/************************************************************************* * * * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. * * All rights reserved. Email: russ@q12.org Web: www.q12.org * * * * This library is free software; you can redistribute it and/or * * modify it under the terms of EITHER: * * (1) The GNU Lesser General Public License as published by the Free * * Software Foundation; either version 2.1 of the License, or (at * * your option) any later version. The text of the GNU Lesser * * General Public License is included with this library in the * * file LICENSE.TXT. * * (2) The BSD-style license that is included with this library in * * the file LICENSE-BSD.TXT. * * * * This library is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files * * LICENSE.TXT and LICENSE-BSD.TXT for more details. * * * *************************************************************************/ /* design note: the general principle for giving a joint the option of connecting to the static environment (i.e. the absolute frame) is to check the second body (joint->node[1].body), and if it is zero then behave as if its body transform is the identity. */ #include #include #include #include #include "joint.h" //**************************************************************************** // externs // extern "C" void dBodyAddTorque (dBodyID, dReal fx, dReal fy, dReal fz); // extern "C" void dBodyAddForce (dBodyID, dReal fx, dReal fy, dReal fz); //**************************************************************************** // utility // set three "ball-and-socket" rows in the constraint equation, and the // corresponding right hand side. static inline void setBall (dxJoint *joint, dxJoint::Info2 *info, dVector3 anchor1, dVector3 anchor2) { // anchor points in global coordinates with respect to body PORs. dVector3 a1,a2; int s = info->rowskip; // set jacobian info->J1l[0] = 1; info->J1l[s+1] = 1; info->J1l[2*s+2] = 1; dMULTIPLY0_331 (a1,joint->node[0].body->posr.R,anchor1); dCROSSMAT (info->J1a,a1,s,-,+); if (joint->node[1].body) { info->J2l[0] = -1; info->J2l[s+1] = -1; info->J2l[2*s+2] = -1; dMULTIPLY0_331 (a2,joint->node[1].body->posr.R,anchor2); dCROSSMAT (info->J2a,a2,s,+,-); } // set right hand side dReal k = info->fps * info->erp; if (joint->node[1].body) { for (int j=0; j<3; j++) { info->c[j] = k * (a2[j] + joint->node[1].body->posr.pos[j] - a1[j] - joint->node[0].body->posr.pos[j]); } } else { for (int j=0; j<3; j++) { info->c[j] = k * (anchor2[j] - a1[j] - joint->node[0].body->posr.pos[j]); } } } // this is like setBall(), except that `axis' is a unit length vector // (in global coordinates) that should be used for the first jacobian // position row (the other two row vectors will be derived from this). // `erp1' is the erp value to use along the axis. static inline void setBall2 (dxJoint *joint, dxJoint::Info2 *info, dVector3 anchor1, dVector3 anchor2, dVector3 axis, dReal erp1) { // anchor points in global coordinates with respect to body PORs. dVector3 a1,a2; int i,s = info->rowskip; // get vectors normal to the axis. in setBall() axis,q1,q2 is [1 0 0], // [0 1 0] and [0 0 1], which makes everything much easier. dVector3 q1,q2; dPlaneSpace (axis,q1,q2); // set jacobian for (i=0; i<3; i++) info->J1l[i] = axis[i]; for (i=0; i<3; i++) info->J1l[s+i] = q1[i]; for (i=0; i<3; i++) info->J1l[2*s+i] = q2[i]; dMULTIPLY0_331 (a1,joint->node[0].body->posr.R,anchor1); dCROSS (info->J1a,=,a1,axis); dCROSS (info->J1a+s,=,a1,q1); dCROSS (info->J1a+2*s,=,a1,q2); if (joint->node[1].body) { for (i=0; i<3; i++) info->J2l[i] = -axis[i]; for (i=0; i<3; i++) info->J2l[s+i] = -q1[i]; for (i=0; i<3; i++) info->J2l[2*s+i] = -q2[i]; dMULTIPLY0_331 (a2,joint->node[1].body->posr.R,anchor2); dCROSS (info->J2a,= -,a2,axis); dCROSS (info->J2a+s,= -,a2,q1); dCROSS (info->J2a+2*s,= -,a2,q2); } // set right hand side - measure error along (axis,q1,q2) dReal k1 = info->fps * erp1; dReal k = info->fps * info->erp; for (i=0; i<3; i++) a1[i] += joint->node[0].body->posr.pos[i]; if (joint->node[1].body) { for (i=0; i<3; i++) a2[i] += joint->node[1].body->posr.pos[i]; info->c[0] = k1 * (dDOT(axis,a2) - dDOT(axis,a1)); info->c[1] = k * (dDOT(q1,a2) - dDOT(q1,a1)); info->c[2] = k * (dDOT(q2,a2) - dDOT(q2,a1)); } else { info->c[0] = k1 * (dDOT(axis,anchor2) - dDOT(axis,a1)); info->c[1] = k * (dDOT(q1,anchor2) - dDOT(q1,a1)); info->c[2] = k * (dDOT(q2,anchor2) - dDOT(q2,a1)); } } // set three orientation rows in the constraint equation, and the // corresponding right hand side. static void setFixedOrientation(dxJoint *joint, dxJoint::Info2 *info, dQuaternion qrel, int start_row) { int s = info->rowskip; int start_index = start_row * s; // 3 rows to make body rotations equal info->J1a[start_index] = 1; info->J1a[start_index + s + 1] = 1; info->J1a[start_index + s*2+2] = 1; if (joint->node[1].body) { info->J2a[start_index] = -1; info->J2a[start_index + s+1] = -1; info->J2a[start_index + s*2+2] = -1; } // compute the right hand side. the first three elements will result in // relative angular velocity of the two bodies - this is set to bring them // back into alignment. the correcting angular velocity is // |angular_velocity| = angle/time = erp*theta / stepsize // = (erp*fps) * theta // angular_velocity = |angular_velocity| * u // = (erp*fps) * theta * u // where rotation along unit length axis u by theta brings body 2's frame // to qrel with respect to body 1's frame. using a small angle approximation // for sin(), this gives // angular_velocity = (erp*fps) * 2 * v // where the quaternion of the relative rotation between the two bodies is // q = [cos(theta/2) sin(theta/2)*u] = [s v] // get qerr = relative rotation (rotation error) between two bodies dQuaternion qerr,e; if (joint->node[1].body) { dQuaternion qq; dQMultiply1 (qq,joint->node[0].body->q,joint->node[1].body->q); dQMultiply2 (qerr,qq,qrel); } else { dQMultiply3 (qerr,joint->node[0].body->q,qrel); } if (qerr[0] < 0) { qerr[1] = -qerr[1]; // adjust sign of qerr to make theta small qerr[2] = -qerr[2]; qerr[3] = -qerr[3]; } dMULTIPLY0_331 (e,joint->node[0].body->posr.R,qerr+1); // @@@ bad SIMD padding! dReal k = info->fps * info->erp; info->c[start_row] = 2*k * e[0]; info->c[start_row+1] = 2*k * e[1]; info->c[start_row+2] = 2*k * e[2]; } // compute anchor points relative to bodies static void setAnchors (dxJoint *j, dReal x, dReal y, dReal z, dVector3 anchor1, dVector3 anchor2) { if (j->node[0].body) { dReal q[4]; q[0] = x - j->node[0].body->posr.pos[0]; q[1] = y - j->node[0].body->posr.pos[1]; q[2] = z - j->node[0].body->posr.pos[2]; q[3] = 0; dMULTIPLY1_331 (anchor1,j->node[0].body->posr.R,q); if (j->node[1].body) { q[0] = x - j->node[1].body->posr.pos[0]; q[1] = y - j->node[1].body->posr.pos[1]; q[2] = z - j->node[1].body->posr.pos[2]; q[3] = 0; dMULTIPLY1_331 (anchor2,j->node[1].body->posr.R,q); } else { anchor2[0] = x; anchor2[1] = y; anchor2[2] = z; } } anchor1[3] = 0; anchor2[3] = 0; } // compute axes relative to bodies. either axis1 or axis2 can be 0. static void setAxes (dxJoint *j, dReal x, dReal y, dReal z, dVector3 axis1, dVector3 axis2) { if (j->node[0].body) { dReal q[4]; q[0] = x; q[1] = y; q[2] = z; q[3] = 0; dNormalize3 (q); if (axis1) { dMULTIPLY1_331 (axis1,j->node[0].body->posr.R,q); axis1[3] = 0; } if (axis2) { if (j->node[1].body) { dMULTIPLY1_331 (axis2,j->node[1].body->posr.R,q); } else { axis2[0] = x; axis2[1] = y; axis2[2] = z; } axis2[3] = 0; } } } static void getAnchor (dxJoint *j, dVector3 result, dVector3 anchor1) { if (j->node[0].body) { dMULTIPLY0_331 (result,j->node[0].body->posr.R,anchor1); result[0] += j->node[0].body->posr.pos[0]; result[1] += j->node[0].body->posr.pos[1]; result[2] += j->node[0].body->posr.pos[2]; } } static void getAnchor2 (dxJoint *j, dVector3 result, dVector3 anchor2) { if (j->node[1].body) { dMULTIPLY0_331 (result,j->node[1].body->posr.R,anchor2); result[0] += j->node[1].body->posr.pos[0]; result[1] += j->node[1].body->posr.pos[1]; result[2] += j->node[1].body->posr.pos[2]; } else { result[0] = anchor2[0]; result[1] = anchor2[1]; result[2] = anchor2[2]; } } static void getAxis (dxJoint *j, dVector3 result, dVector3 axis1) { if (j->node[0].body) { dMULTIPLY0_331 (result,j->node[0].body->posr.R,axis1); } } static void getAxis2 (dxJoint *j, dVector3 result, dVector3 axis2) { if (j->node[1].body) { dMULTIPLY0_331 (result,j->node[1].body->posr.R,axis2); } else { result[0] = axis2[0]; result[1] = axis2[1]; result[2] = axis2[2]; } } static dReal getHingeAngleFromRelativeQuat (dQuaternion qrel, dVector3 axis) { // the angle between the two bodies is extracted from the quaternion that // represents the relative rotation between them. recall that a quaternion // q is: // [s,v] = [ cos(theta/2) , sin(theta/2) * u ] // where s is a scalar and v is a 3-vector. u is a unit length axis and // theta is a rotation along that axis. we can get theta/2 by: // theta/2 = atan2 ( sin(theta/2) , cos(theta/2) ) // but we can't get sin(theta/2) directly, only its absolute value, i.e.: // |v| = |sin(theta/2)| * |u| // = |sin(theta/2)| // using this value will have a strange effect. recall that there are two // quaternion representations of a given rotation, q and -q. typically as // a body rotates along the axis it will go through a complete cycle using // one representation and then the next cycle will use the other // representation. this corresponds to u pointing in the direction of the // hinge axis and then in the opposite direction. the result is that theta // will appear to go "backwards" every other cycle. here is a fix: if u // points "away" from the direction of the hinge (motor) axis (i.e. more // than 90 degrees) then use -q instead of q. this represents the same // rotation, but results in the cos(theta/2) value being sign inverted. // extract the angle from the quaternion. cost2 = cos(theta/2), // sint2 = |sin(theta/2)| dReal cost2 = qrel[0]; dReal sint2 = dSqrt (qrel[1]*qrel[1]+qrel[2]*qrel[2]+qrel[3]*qrel[3]); dReal theta = (dDOT(qrel+1,axis) >= 0) ? // @@@ padding assumptions (2 * dAtan2(sint2,cost2)) : // if u points in direction of axis (2 * dAtan2(sint2,-cost2)); // if u points in opposite direction // the angle we get will be between 0..2*pi, but we want to return angles // between -pi..pi if (theta > M_PI) theta -= 2*M_PI; // the angle we've just extracted has the wrong sign theta = -theta; return theta; } // given two bodies (body1,body2), the hinge axis that they are connected by // w.r.t. body1 (axis), and the initial relative orientation between them // (q_initial), return the relative rotation angle. the initial relative // orientation corresponds to an angle of zero. if body2 is 0 then measure the // angle between body1 and the static frame. // // this will not return the correct angle if the bodies rotate along any axis // other than the given hinge axis. static dReal getHingeAngle (dxBody *body1, dxBody *body2, dVector3 axis, dQuaternion q_initial) { // get qrel = relative rotation between the two bodies dQuaternion qrel; if (body2) { dQuaternion qq; dQMultiply1 (qq,body1->q,body2->q); dQMultiply2 (qrel,qq,q_initial); } else { // pretend body2->q is the identity dQMultiply3 (qrel,body1->q,q_initial); } return getHingeAngleFromRelativeQuat (qrel,axis); } //**************************************************************************** // dxJointLimitMotor void dxJointLimitMotor::init (dxWorld *world) { vel = 0; fmax = 0; lostop = -dInfinity; histop = dInfinity; fudge_factor = 1; normal_cfm = world->global_cfm; stop_erp = world->global_erp; stop_cfm = world->global_cfm; bounce = 0; limit = 0; limit_err = 0; } void dxJointLimitMotor::set (int num, dReal value) { switch (num) { case dParamLoStop: lostop = value; break; case dParamHiStop: histop = value; break; case dParamVel: vel = value; break; case dParamFMax: if (value >= 0) fmax = value; break; case dParamFudgeFactor: if (value >= 0 && value <= 1) fudge_factor = value; break; case dParamBounce: bounce = value; break; case dParamCFM: normal_cfm = value; break; case dParamStopERP: stop_erp = value; break; case dParamStopCFM: stop_cfm = value; break; } } dReal dxJointLimitMotor::get (int num) { switch (num) { case dParamLoStop: return lostop; case dParamHiStop: return histop; case dParamVel: return vel; case dParamFMax: return fmax; case dParamFudgeFactor: return fudge_factor; case dParamBounce: return bounce; case dParamCFM: return normal_cfm; case dParamStopERP: return stop_erp; case dParamStopCFM: return stop_cfm; default: return 0; } } int dxJointLimitMotor::testRotationalLimit (dReal angle) { if (angle <= lostop) { limit = 1; limit_err = angle - lostop; return 1; } else if (angle >= histop) { limit = 2; limit_err = angle - histop; return 1; } else { limit = 0; return 0; } } int dxJointLimitMotor::addLimot (dxJoint *joint, dxJoint::Info2 *info, int row, dVector3 ax1, int rotational) { int srow = row * info->rowskip; // if the joint is powered, or has joint limits, add in the extra row int powered = fmax > 0; if (powered || limit) { dReal *J1 = rotational ? info->J1a : info->J1l; dReal *J2 = rotational ? info->J2a : info->J2l; J1[srow+0] = ax1[0]; J1[srow+1] = ax1[1]; J1[srow+2] = ax1[2]; if (joint->node[1].body) { J2[srow+0] = -ax1[0]; J2[srow+1] = -ax1[1]; J2[srow+2] = -ax1[2]; } // linear limot torque decoupling step: // // if this is a linear limot (e.g. from a slider), we have to be careful // that the linear constraint forces (+/- ax1) applied to the two bodies // do not create a torque couple. in other words, the points that the // constraint force is applied at must lie along the same ax1 axis. // a torque couple will result in powered or limited slider-jointed free // bodies from gaining angular momentum. // the solution used here is to apply the constraint forces at the point // halfway between the body centers. there is no penalty (other than an // extra tiny bit of computation) in doing this adjustment. note that we // only need to do this if the constraint connects two bodies. dVector3 ltd; // Linear Torque Decoupling vector (a torque) if (!rotational && joint->node[1].body) { dVector3 c; c[0]=REAL(0.5)*(joint->node[1].body->posr.pos[0]-joint->node[0].body->posr.pos[0]); c[1]=REAL(0.5)*(joint->node[1].body->posr.pos[1]-joint->node[0].body->posr.pos[1]); c[2]=REAL(0.5)*(joint->node[1].body->posr.pos[2]-joint->node[0].body->posr.pos[2]); dCROSS (ltd,=,c,ax1); info->J1a[srow+0] = ltd[0]; info->J1a[srow+1] = ltd[1]; info->J1a[srow+2] = ltd[2]; info->J2a[srow+0] = ltd[0]; info->J2a[srow+1] = ltd[1]; info->J2a[srow+2] = ltd[2]; } // if we're limited low and high simultaneously, the joint motor is // ineffective if (limit && (lostop == histop)) powered = 0; if (powered) { info->cfm[row] = normal_cfm; if (! limit) { info->c[row] = vel; info->lo[row] = -fmax; info->hi[row] = fmax; } else { // the joint is at a limit, AND is being powered. if the joint is // being powered into the limit then we apply the maximum motor force // in that direction, because the motor is working against the // immovable limit. if the joint is being powered away from the limit // then we have problems because actually we need *two* lcp // constraints to handle this case. so we fake it and apply some // fraction of the maximum force. the fraction to use can be set as // a fudge factor. dReal fm = fmax; if ((vel > 0) || (vel==0 && limit==2)) fm = -fm; // if we're powering away from the limit, apply the fudge factor if ((limit==1 && vel > 0) || (limit==2 && vel < 0)) fm *= fudge_factor; if (rotational) { dBodyAddTorque (joint->node[0].body,-fm*ax1[0],-fm*ax1[1], -fm*ax1[2]); if (joint->node[1].body) dBodyAddTorque (joint->node[1].body,fm*ax1[0],fm*ax1[1],fm*ax1[2]); } else { dBodyAddForce (joint->node[0].body,-fm*ax1[0],-fm*ax1[1],-fm*ax1[2]); if (joint->node[1].body) { dBodyAddForce (joint->node[1].body,fm*ax1[0],fm*ax1[1],fm*ax1[2]); // linear limot torque decoupling step: refer to above discussion dBodyAddTorque (joint->node[0].body,-fm*ltd[0],-fm*ltd[1], -fm*ltd[2]); dBodyAddTorque (joint->node[1].body,-fm*ltd[0],-fm*ltd[1], -fm*ltd[2]); } } } } if (limit) { dReal k = info->fps * stop_erp; info->c[row] = -k * limit_err; info->cfm[row] = stop_cfm; if (lostop == histop) { // limited low and high simultaneously info->lo[row] = -dInfinity; info->hi[row] = dInfinity; } else { if (limit == 1) { // low limit info->lo[row] = 0; info->hi[row] = dInfinity; } else { // high limit info->lo[row] = -dInfinity; info->hi[row] = 0; } // deal with bounce if (bounce > 0) { // calculate joint velocity dReal vel; if (rotational) { vel = dDOT(joint->node[0].body->avel,ax1); if (joint->node[1].body) vel -= dDOT(joint->node[1].body->avel,ax1); } else { vel = dDOT(joint->node[0].body->lvel,ax1); if (joint->node[1].body) vel -= dDOT(joint->node[1].body->lvel,ax1); } // only apply bounce if the velocity is incoming, and if the // resulting c[] exceeds what we already have. if (limit == 1) { // low limit if (vel < 0) { dReal newc = -bounce * vel; if (newc > info->c[row]) info->c[row] = newc; } } else { // high limit - all those computations are reversed if (vel > 0) { dReal newc = -bounce * vel; if (newc < info->c[row]) info->c[row] = newc; } } } } } return 1; } else return 0; } //**************************************************************************** // ball and socket static void ballInit (dxJointBall *j) { dSetZero (j->anchor1,4); dSetZero (j->anchor2,4); } static void ballGetInfo1 (dxJointBall *j, dxJoint::Info1 *info) { info->m = 3; info->nub = 3; } static void ballGetInfo2 (dxJointBall *joint, dxJoint::Info2 *info) { setBall (joint,info,joint->anchor1,joint->anchor2); } void dJointSetBallAnchor (dJointID j, dReal x, dReal y, dReal z) { dxJointBall* joint = (dxJointBall*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dball_vtable,"joint is not a ball"); setAnchors (joint,x,y,z,joint->anchor1,joint->anchor2); } void dJointSetBallAnchor2 (dJointID j, dReal x, dReal y, dReal z) { dxJointBall* joint = (dxJointBall*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dball_vtable,"joint is not a ball"); joint->anchor2[0] = x; joint->anchor2[1] = y; joint->anchor2[2] = z; joint->anchor2[3] = 0; } void dJointGetBallAnchor (dJointID j, dVector3 result) { dxJointBall* joint = (dxJointBall*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dball_vtable,"joint is not a ball"); if (joint->flags & dJOINT_REVERSE) getAnchor2 (joint,result,joint->anchor2); else getAnchor (joint,result,joint->anchor1); } void dJointGetBallAnchor2 (dJointID j, dVector3 result) { dxJointBall* joint = (dxJointBall*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dball_vtable,"joint is not a ball"); if (joint->flags & dJOINT_REVERSE) getAnchor (joint,result,joint->anchor1); else getAnchor2 (joint,result,joint->anchor2); } dxJoint::Vtable __dball_vtable = { sizeof(dxJointBall), (dxJoint::init_fn*) ballInit, (dxJoint::getInfo1_fn*) ballGetInfo1, (dxJoint::getInfo2_fn*) ballGetInfo2, dJointTypeBall}; //**************************************************************************** // hinge static void hingeInit (dxJointHinge *j) { dSetZero (j->anchor1,4); dSetZero (j->anchor2,4); dSetZero (j->axis1,4); j->axis1[0] = 1; dSetZero (j->axis2,4); j->axis2[0] = 1; dSetZero (j->qrel,4); j->limot.init (j->world); } static void hingeGetInfo1 (dxJointHinge *j, dxJoint::Info1 *info) { info->nub = 5; // see if joint is powered if (j->limot.fmax > 0) info->m = 6; // powered hinge needs an extra constraint row else info->m = 5; // see if we're at a joint limit. if ((j->limot.lostop >= -M_PI || j->limot.histop <= M_PI) && j->limot.lostop <= j->limot.histop) { dReal angle = getHingeAngle (j->node[0].body,j->node[1].body,j->axis1, j->qrel); if (j->limot.testRotationalLimit (angle)) info->m = 6; } } static void hingeGetInfo2 (dxJointHinge *joint, dxJoint::Info2 *info) { // set the three ball-and-socket rows setBall (joint,info,joint->anchor1,joint->anchor2); // set the two hinge rows. the hinge axis should be the only unconstrained // rotational axis, the angular velocity of the two bodies perpendicular to // the hinge axis should be equal. thus the constraint equations are // p*w1 - p*w2 = 0 // q*w1 - q*w2 = 0 // where p and q are unit vectors normal to the hinge axis, and w1 and w2 // are the angular velocity vectors of the two bodies. dVector3 ax1; // length 1 joint axis in global coordinates, from 1st body dVector3 p,q; // plane space vectors for ax1 dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); dPlaneSpace (ax1,p,q); int s3=3*info->rowskip; int s4=4*info->rowskip; info->J1a[s3+0] = p[0]; info->J1a[s3+1] = p[1]; info->J1a[s3+2] = p[2]; info->J1a[s4+0] = q[0]; info->J1a[s4+1] = q[1]; info->J1a[s4+2] = q[2]; if (joint->node[1].body) { info->J2a[s3+0] = -p[0]; info->J2a[s3+1] = -p[1]; info->J2a[s3+2] = -p[2]; info->J2a[s4+0] = -q[0]; info->J2a[s4+1] = -q[1]; info->J2a[s4+2] = -q[2]; } // compute the right hand side of the constraint equation. set relative // body velocities along p and q to bring the hinge back into alignment. // if ax1,ax2 are the unit length hinge axes as computed from body1 and // body2, we need to rotate both bodies along the axis u = (ax1 x ax2). // if `theta' is the angle between ax1 and ax2, we need an angular velocity // along u to cover angle erp*theta in one step : // |angular_velocity| = angle/time = erp*theta / stepsize // = (erp*fps) * theta // angular_velocity = |angular_velocity| * (ax1 x ax2) / |ax1 x ax2| // = (erp*fps) * theta * (ax1 x ax2) / sin(theta) // ...as ax1 and ax2 are unit length. if theta is smallish, // theta ~= sin(theta), so // angular_velocity = (erp*fps) * (ax1 x ax2) // ax1 x ax2 is in the plane space of ax1, so we project the angular // velocity to p and q to find the right hand side. dVector3 ax2,b; if (joint->node[1].body) { dMULTIPLY0_331 (ax2,joint->node[1].body->posr.R,joint->axis2); } else { ax2[0] = joint->axis2[0]; ax2[1] = joint->axis2[1]; ax2[2] = joint->axis2[2]; } dCROSS (b,=,ax1,ax2); dReal k = info->fps * info->erp; info->c[3] = k * dDOT(b,p); info->c[4] = k * dDOT(b,q); // if the hinge is powered, or has joint limits, add in the stuff joint->limot.addLimot (joint,info,5,ax1,1); } // compute initial relative rotation body1 -> body2, or env -> body1 static void hingeComputeInitialRelativeRotation (dxJointHinge *joint) { if (joint->node[0].body) { if (joint->node[1].body) { dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); } else { // set joint->qrel to the transpose of the first body q joint->qrel[0] = joint->node[0].body->q[0]; for (int i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; } } } void dJointSetHingeAnchor (dJointID j, dReal x, dReal y, dReal z) { dxJointHinge* joint = (dxJointHinge*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a hinge"); setAnchors (joint,x,y,z,joint->anchor1,joint->anchor2); hingeComputeInitialRelativeRotation (joint); } void dJointSetHingeAnchorDelta (dJointID j, dReal x, dReal y, dReal z, dReal dx, dReal dy, dReal dz) { dxJointHinge* joint = (dxJointHinge*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a hinge"); if (joint->node[0].body) { dReal q[4]; q[0] = x - joint->node[0].body->posr.pos[0]; q[1] = y - joint->node[0].body->posr.pos[1]; q[2] = z - joint->node[0].body->posr.pos[2]; q[3] = 0; dMULTIPLY1_331 (joint->anchor1,joint->node[0].body->posr.R,q); if (joint->node[1].body) { q[0] = x - joint->node[1].body->posr.pos[0]; q[1] = y - joint->node[1].body->posr.pos[1]; q[2] = z - joint->node[1].body->posr.pos[2]; q[3] = 0; dMULTIPLY1_331 (joint->anchor2,joint->node[1].body->posr.R,q); } else { // Move the relative displacement between the passive body and the // anchor in the same direction as the passive body has just moved joint->anchor2[0] = x + dx; joint->anchor2[1] = y + dy; joint->anchor2[2] = z + dz; } } joint->anchor1[3] = 0; joint->anchor2[3] = 0; hingeComputeInitialRelativeRotation (joint); } void dJointSetHingeAxis (dJointID j, dReal x, dReal y, dReal z) { dxJointHinge* joint = (dxJointHinge*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a hinge"); setAxes (joint,x,y,z,joint->axis1,joint->axis2); hingeComputeInitialRelativeRotation (joint); } void dJointGetHingeAnchor (dJointID j, dVector3 result) { dxJointHinge* joint = (dxJointHinge*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a hinge"); if (joint->flags & dJOINT_REVERSE) getAnchor2 (joint,result,joint->anchor2); else getAnchor (joint,result,joint->anchor1); } void dJointGetHingeAnchor2 (dJointID j, dVector3 result) { dxJointHinge* joint = (dxJointHinge*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a hinge"); if (joint->flags & dJOINT_REVERSE) getAnchor (joint,result,joint->anchor1); else getAnchor2 (joint,result,joint->anchor2); } void dJointGetHingeAxis (dJointID j, dVector3 result) { dxJointHinge* joint = (dxJointHinge*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a hinge"); getAxis (joint,result,joint->axis1); } void dJointSetHingeParam (dJointID j, int parameter, dReal value) { dxJointHinge* joint = (dxJointHinge*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a hinge"); joint->limot.set (parameter,value); } dReal dJointGetHingeParam (dJointID j, int parameter) { dxJointHinge* joint = (dxJointHinge*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a hinge"); return joint->limot.get (parameter); } dReal dJointGetHingeAngle (dJointID j) { dxJointHinge* joint = (dxJointHinge*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a hinge"); if (joint->node[0].body) { dReal ang = getHingeAngle (joint->node[0].body,joint->node[1].body,joint->axis1, joint->qrel); if (joint->flags & dJOINT_REVERSE) return -ang; else return ang; } else return 0; } dReal dJointGetHingeAngleRate (dJointID j) { dxJointHinge* joint = (dxJointHinge*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a Hinge"); if (joint->node[0].body) { dVector3 axis; dMULTIPLY0_331 (axis,joint->node[0].body->posr.R,joint->axis1); dReal rate = dDOT(axis,joint->node[0].body->avel); if (joint->node[1].body) rate -= dDOT(axis,joint->node[1].body->avel); if (joint->flags & dJOINT_REVERSE) rate = - rate; return rate; } else return 0; } void dJointAddHingeTorque (dJointID j, dReal torque) { dxJointHinge* joint = (dxJointHinge*)j; dVector3 axis; dAASSERT(joint); dUASSERT(joint->vtable == &__dhinge_vtable,"joint is not a Hinge"); if (joint->flags & dJOINT_REVERSE) torque = -torque; getAxis (joint,axis,joint->axis1); axis[0] *= torque; axis[1] *= torque; axis[2] *= torque; if (joint->node[0].body != 0) dBodyAddTorque (joint->node[0].body, axis[0], axis[1], axis[2]); if (joint->node[1].body != 0) dBodyAddTorque(joint->node[1].body, -axis[0], -axis[1], -axis[2]); } dxJoint::Vtable __dhinge_vtable = { sizeof(dxJointHinge), (dxJoint::init_fn*) hingeInit, (dxJoint::getInfo1_fn*) hingeGetInfo1, (dxJoint::getInfo2_fn*) hingeGetInfo2, dJointTypeHinge}; //**************************************************************************** // slider static void sliderInit (dxJointSlider *j) { dSetZero (j->axis1,4); j->axis1[0] = 1; dSetZero (j->qrel,4); dSetZero (j->offset,4); j->limot.init (j->world); } dReal dJointGetSliderPosition (dJointID j) { dxJointSlider* joint = (dxJointSlider*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dslider_vtable,"joint is not a slider"); // get axis1 in global coordinates dVector3 ax1,q; dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); if (joint->node[1].body) { // get body2 + offset point in global coordinates dMULTIPLY0_331 (q,joint->node[1].body->posr.R,joint->offset); for (int i=0; i<3; i++) q[i] = joint->node[0].body->posr.pos[i] - q[i] - joint->node[1].body->posr.pos[i]; } else { for (int i=0; i<3; i++) q[i] = joint->node[0].body->posr.pos[i] - joint->offset[i]; } return dDOT(ax1,q); } dReal dJointGetSliderPositionRate (dJointID j) { dxJointSlider* joint = (dxJointSlider*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dslider_vtable,"joint is not a slider"); // get axis1 in global coordinates dVector3 ax1; dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); if (joint->node[1].body) { return dDOT(ax1,joint->node[0].body->lvel) - dDOT(ax1,joint->node[1].body->lvel); } else { return dDOT(ax1,joint->node[0].body->lvel); } } static void sliderGetInfo1 (dxJointSlider *j, dxJoint::Info1 *info) { info->nub = 5; // see if joint is powered if (j->limot.fmax > 0) info->m = 6; // powered slider needs an extra constraint row else info->m = 5; // see if we're at a joint limit. j->limot.limit = 0; if ((j->limot.lostop > -dInfinity || j->limot.histop < dInfinity) && j->limot.lostop <= j->limot.histop) { // measure joint position dReal pos = dJointGetSliderPosition (j); if (pos <= j->limot.lostop) { j->limot.limit = 1; j->limot.limit_err = pos - j->limot.lostop; info->m = 6; } else if (pos >= j->limot.histop) { j->limot.limit = 2; j->limot.limit_err = pos - j->limot.histop; info->m = 6; } } } static void sliderGetInfo2 (dxJointSlider *joint, dxJoint::Info2 *info) { int i,s = info->rowskip; int s3=3*s,s4=4*s; // pull out pos and R for both bodies. also get the `connection' // vector pos2-pos1. dReal *pos1,*pos2,*R1,*R2; dVector3 c; pos1 = joint->node[0].body->posr.pos; R1 = joint->node[0].body->posr.R; if (joint->node[1].body) { pos2 = joint->node[1].body->posr.pos; R2 = joint->node[1].body->posr.R; for (i=0; i<3; i++) c[i] = pos2[i] - pos1[i]; } else { pos2 = 0; R2 = 0; } // 3 rows to make body rotations equal setFixedOrientation(joint, info, joint->qrel, 0); // remaining two rows. we want: vel2 = vel1 + w1 x c ... but this would // result in three equations, so we project along the planespace vectors // so that sliding along the slider axis is disregarded. for symmetry we // also substitute (w1+w2)/2 for w1, as w1 is supposed to equal w2. dVector3 ax1; // joint axis in global coordinates (unit length) dVector3 p,q; // plane space of ax1 dMULTIPLY0_331 (ax1,R1,joint->axis1); dPlaneSpace (ax1,p,q); if (joint->node[1].body) { dVector3 tmp; dCROSS (tmp, = REAL(0.5) * ,c,p); for (i=0; i<3; i++) info->J1a[s3+i] = tmp[i]; for (i=0; i<3; i++) info->J2a[s3+i] = tmp[i]; dCROSS (tmp, = REAL(0.5) * ,c,q); for (i=0; i<3; i++) info->J1a[s4+i] = tmp[i]; for (i=0; i<3; i++) info->J2a[s4+i] = tmp[i]; for (i=0; i<3; i++) info->J2l[s3+i] = -p[i]; for (i=0; i<3; i++) info->J2l[s4+i] = -q[i]; } for (i=0; i<3; i++) info->J1l[s3+i] = p[i]; for (i=0; i<3; i++) info->J1l[s4+i] = q[i]; // compute last two elements of right hand side. we want to align the offset // point (in body 2's frame) with the center of body 1. dReal k = info->fps * info->erp; if (joint->node[1].body) { dVector3 ofs; // offset point in global coordinates dMULTIPLY0_331 (ofs,R2,joint->offset); for (i=0; i<3; i++) c[i] += ofs[i]; info->c[3] = k * dDOT(p,c); info->c[4] = k * dDOT(q,c); } else { dVector3 ofs; // offset point in global coordinates for (i=0; i<3; i++) ofs[i] = joint->offset[i] - pos1[i]; info->c[3] = k * dDOT(p,ofs); info->c[4] = k * dDOT(q,ofs); } // if the slider is powered, or has joint limits, add in the extra row joint->limot.addLimot (joint,info,5,ax1,0); } void dJointSetSliderAxis (dJointID j, dReal x, dReal y, dReal z) { dxJointSlider* joint = (dxJointSlider*)j; int i; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dslider_vtable,"joint is not a slider"); setAxes (joint,x,y,z,joint->axis1,0); // compute initial relative rotation body1 -> body2, or env -> body1 // also compute center of body1 w.r.t body 2 if (joint->node[1].body) { dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); dVector3 c; for (i=0; i<3; i++) c[i] = joint->node[0].body->posr.pos[i] - joint->node[1].body->posr.pos[i]; dMULTIPLY1_331 (joint->offset,joint->node[1].body->posr.R,c); } else { // set joint->qrel to the transpose of the first body's q joint->qrel[0] = joint->node[0].body->q[0]; for (i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; for (i=0; i<3; i++) joint->offset[i] = joint->node[0].body->posr.pos[i]; } } void dJointSetSliderAxisDelta (dJointID j, dReal x, dReal y, dReal z, dReal dx, dReal dy, dReal dz) { dxJointSlider* joint = (dxJointSlider*)j; int i; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dslider_vtable,"joint is not a slider"); setAxes (joint,x,y,z,joint->axis1,0); // compute initial relative rotation body1 -> body2, or env -> body1 // also compute center of body1 w.r.t body 2 if (joint->node[1].body) { dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); dVector3 c; for (i=0; i<3; i++) c[i] = joint->node[0].body->posr.pos[i] - joint->node[1].body->posr.pos[i]; dMULTIPLY1_331 (joint->offset,joint->node[1].body->posr.R,c); } else { // set joint->qrel to the transpose of the first body's q joint->qrel[0] = joint->node[0].body->q[0]; for (i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; joint->offset[0] = joint->node[0].body->posr.pos[0] + dx; joint->offset[1] = joint->node[0].body->posr.pos[1] + dy; joint->offset[2] = joint->node[0].body->posr.pos[2] + dz; } } void dJointGetSliderAxis (dJointID j, dVector3 result) { dxJointSlider* joint = (dxJointSlider*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dslider_vtable,"joint is not a slider"); getAxis (joint,result,joint->axis1); } void dJointSetSliderParam (dJointID j, int parameter, dReal value) { dxJointSlider* joint = (dxJointSlider*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dslider_vtable,"joint is not a slider"); joint->limot.set (parameter,value); } dReal dJointGetSliderParam (dJointID j, int parameter) { dxJointSlider* joint = (dxJointSlider*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dslider_vtable,"joint is not a slider"); return joint->limot.get (parameter); } void dJointAddSliderForce (dJointID j, dReal force) { dxJointSlider* joint = (dxJointSlider*)j; dVector3 axis; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dslider_vtable,"joint is not a slider"); if (joint->flags & dJOINT_REVERSE) force -= force; getAxis (joint,axis,joint->axis1); axis[0] *= force; axis[1] *= force; axis[2] *= force; if (joint->node[0].body != 0) dBodyAddForce (joint->node[0].body,axis[0],axis[1],axis[2]); if (joint->node[1].body != 0) dBodyAddForce(joint->node[1].body, -axis[0], -axis[1], -axis[2]); if (joint->node[0].body != 0 && joint->node[1].body != 0) { // linear torque decoupling: // we have to compensate the torque, that this slider force may generate // if body centers are not aligned along the slider axis dVector3 ltd; // Linear Torque Decoupling vector (a torque) dVector3 c; c[0]=REAL(0.5)*(joint->node[1].body->posr.pos[0]-joint->node[0].body->posr.pos[0]); c[1]=REAL(0.5)*(joint->node[1].body->posr.pos[1]-joint->node[0].body->posr.pos[1]); c[2]=REAL(0.5)*(joint->node[1].body->posr.pos[2]-joint->node[0].body->posr.pos[2]); dCROSS (ltd,=,c,axis); dBodyAddTorque (joint->node[0].body,ltd[0],ltd[1], ltd[2]); dBodyAddTorque (joint->node[1].body,ltd[0],ltd[1], ltd[2]); } } dxJoint::Vtable __dslider_vtable = { sizeof(dxJointSlider), (dxJoint::init_fn*) sliderInit, (dxJoint::getInfo1_fn*) sliderGetInfo1, (dxJoint::getInfo2_fn*) sliderGetInfo2, dJointTypeSlider}; //**************************************************************************** // contact static void contactInit (dxJointContact *j) { // default frictionless contact. hmmm, this info gets overwritten straight // away anyway, so why bother? #if 0 /* so don't bother ;) */ j->contact.surface.mode = 0; j->contact.surface.mu = 0; dSetZero (j->contact.geom.pos,4); dSetZero (j->contact.geom.normal,4); j->contact.geom.depth = 0; #endif } static void contactGetInfo1 (dxJointContact *j, dxJoint::Info1 *info) { // make sure mu's >= 0, then calculate number of constraint rows and number // of unbounded rows. int m = 1, nub=0; if (j->contact.surface.mu < 0) j->contact.surface.mu = 0; if (j->contact.surface.mode & dContactMu2) { if (j->contact.surface.mu > 0) m++; if (j->contact.surface.mu2 < 0) j->contact.surface.mu2 = 0; if (j->contact.surface.mu2 > 0) m++; if (j->contact.surface.mu == dInfinity) nub ++; if (j->contact.surface.mu2 == dInfinity) nub ++; } else { if (j->contact.surface.mu > 0) m += 2; if (j->contact.surface.mu == dInfinity) nub += 2; } j->the_m = m; info->m = m; info->nub = nub; } static void contactGetInfo2 (dxJointContact *j, dxJoint::Info2 *info) { int s = info->rowskip; int s2 = 2*s; // get normal, with sign adjusted for body1/body2 polarity dVector3 normal; if (j->flags & dJOINT_REVERSE) { normal[0] = - j->contact.geom.normal[0]; normal[1] = - j->contact.geom.normal[1]; normal[2] = - j->contact.geom.normal[2]; } else { normal[0] = j->contact.geom.normal[0]; normal[1] = j->contact.geom.normal[1]; normal[2] = j->contact.geom.normal[2]; } normal[3] = 0; // @@@ hmmm // c1,c2 = contact points with respect to body PORs dVector3 c1,c2; c1[0] = j->contact.geom.pos[0] - j->node[0].body->posr.pos[0]; c1[1] = j->contact.geom.pos[1] - j->node[0].body->posr.pos[1]; c1[2] = j->contact.geom.pos[2] - j->node[0].body->posr.pos[2]; // set jacobian for normal info->J1l[0] = normal[0]; info->J1l[1] = normal[1]; info->J1l[2] = normal[2]; dCROSS (info->J1a,=,c1,normal); if (j->node[1].body) { c2[0] = j->contact.geom.pos[0] - j->node[1].body->posr.pos[0]; c2[1] = j->contact.geom.pos[1] - j->node[1].body->posr.pos[1]; c2[2] = j->contact.geom.pos[2] - j->node[1].body->posr.pos[2]; info->J2l[0] = -normal[0]; info->J2l[1] = -normal[1]; info->J2l[2] = -normal[2]; dCROSS (info->J2a,= -,c2,normal); } // set right hand side and cfm value for normal dReal erp = info->erp; if (j->contact.surface.mode & dContactSoftERP) erp = j->contact.surface.soft_erp; dReal k = info->fps * erp; dReal depth = j->contact.geom.depth - j->world->contactp.min_depth; if (depth < 0) depth = 0; dReal maxvel = j->world->contactp.max_vel; if (k*depth > maxvel) info->c[0] = maxvel; else info->c[0] = k*depth; if (j->contact.surface.mode & dContactSoftCFM) info->cfm[0] = j->contact.surface.soft_cfm; // deal with bounce if (j->contact.surface.mode & dContactBounce) { // calculate outgoing velocity (-ve for incoming contact) dReal outgoing = dDOT(info->J1l,j->node[0].body->lvel) + dDOT(info->J1a,j->node[0].body->avel); if (j->node[1].body) { outgoing += dDOT(info->J2l,j->node[1].body->lvel) + dDOT(info->J2a,j->node[1].body->avel); } // only apply bounce if the outgoing velocity is greater than the // threshold, and if the resulting c[0] exceeds what we already have. if (j->contact.surface.bounce_vel >= 0 && (-outgoing) > j->contact.surface.bounce_vel) { dReal newc = - j->contact.surface.bounce * outgoing; if (newc > info->c[0]) info->c[0] = newc; } } // set LCP limits for normal info->lo[0] = 0; info->hi[0] = dInfinity; // now do jacobian for tangential forces dVector3 t1,t2; // two vectors tangential to normal // first friction direction if (j->the_m >= 2) { if (j->contact.surface.mode & dContactFDir1) { // use fdir1 ? t1[0] = j->contact.fdir1[0]; t1[1] = j->contact.fdir1[1]; t1[2] = j->contact.fdir1[2]; dCROSS (t2,=,normal,t1); } else { dPlaneSpace (normal,t1,t2); } info->J1l[s+0] = t1[0]; info->J1l[s+1] = t1[1]; info->J1l[s+2] = t1[2]; dCROSS (info->J1a+s,=,c1,t1); if (j->node[1].body) { info->J2l[s+0] = -t1[0]; info->J2l[s+1] = -t1[1]; info->J2l[s+2] = -t1[2]; dCROSS (info->J2a+s,= -,c2,t1); } // set right hand side if (j->contact.surface.mode & dContactMotion1) { info->c[1] = j->contact.surface.motion1; } // set LCP bounds and friction index. this depends on the approximation // mode info->lo[1] = -j->contact.surface.mu; info->hi[1] = j->contact.surface.mu; if (j->contact.surface.mode & dContactApprox1_1) info->findex[1] = 0; // set slip (constraint force mixing) if (j->contact.surface.mode & dContactSlip1) info->cfm[1] = j->contact.surface.slip1; } // second friction direction if (j->the_m >= 3) { info->J1l[s2+0] = t2[0]; info->J1l[s2+1] = t2[1]; info->J1l[s2+2] = t2[2]; dCROSS (info->J1a+s2,=,c1,t2); if (j->node[1].body) { info->J2l[s2+0] = -t2[0]; info->J2l[s2+1] = -t2[1]; info->J2l[s2+2] = -t2[2]; dCROSS (info->J2a+s2,= -,c2,t2); } // set right hand side if (j->contact.surface.mode & dContactMotion2) { info->c[2] = j->contact.surface.motion2; } // set LCP bounds and friction index. this depends on the approximation // mode if (j->contact.surface.mode & dContactMu2) { info->lo[2] = -j->contact.surface.mu2; info->hi[2] = j->contact.surface.mu2; } else { info->lo[2] = -j->contact.surface.mu; info->hi[2] = j->contact.surface.mu; } if (j->contact.surface.mode & dContactApprox1_2) info->findex[2] = 0; // set slip (constraint force mixing) if (j->contact.surface.mode & dContactSlip2) info->cfm[2] = j->contact.surface.slip2; } } dxJoint::Vtable __dcontact_vtable = { sizeof(dxJointContact), (dxJoint::init_fn*) contactInit, (dxJoint::getInfo1_fn*) contactGetInfo1, (dxJoint::getInfo2_fn*) contactGetInfo2, dJointTypeContact}; //**************************************************************************** // hinge 2. note that this joint must be attached to two bodies for it to work static dReal measureHinge2Angle (dxJointHinge2 *joint) { dVector3 a1,a2; dMULTIPLY0_331 (a1,joint->node[1].body->posr.R,joint->axis2); dMULTIPLY1_331 (a2,joint->node[0].body->posr.R,a1); dReal x = dDOT(joint->v1,a2); dReal y = dDOT(joint->v2,a2); return -dAtan2 (y,x); } static void hinge2Init (dxJointHinge2 *j) { dSetZero (j->anchor1,4); dSetZero (j->anchor2,4); dSetZero (j->axis1,4); j->axis1[0] = 1; dSetZero (j->axis2,4); j->axis2[1] = 1; j->c0 = 0; j->s0 = 0; dSetZero (j->v1,4); j->v1[0] = 1; dSetZero (j->v2,4); j->v2[1] = 1; j->limot1.init (j->world); j->limot2.init (j->world); j->susp_erp = j->world->global_erp; j->susp_cfm = j->world->global_cfm; j->flags |= dJOINT_TWOBODIES; } static void hinge2GetInfo1 (dxJointHinge2 *j, dxJoint::Info1 *info) { info->m = 4; info->nub = 4; // see if we're powered or at a joint limit for axis 1 int atlimit=0; if ((j->limot1.lostop >= -M_PI || j->limot1.histop <= M_PI) && j->limot1.lostop <= j->limot1.histop) { dReal angle = measureHinge2Angle (j); if (j->limot1.testRotationalLimit (angle)) atlimit = 1; } if (atlimit || j->limot1.fmax > 0) info->m++; // see if we're powering axis 2 (we currently never limit this axis) j->limot2.limit = 0; if (j->limot2.fmax > 0) info->m++; } // macro that computes ax1,ax2 = axis 1 and 2 in global coordinates (they are // relative to body 1 and 2 initially) and then computes the constrained // rotational axis as the cross product of ax1 and ax2. // the sin and cos of the angle between axis 1 and 2 is computed, this comes // from dot and cross product rules. #define HINGE2_GET_AXIS_INFO(axis,sin_angle,cos_angle) \ dVector3 ax1,ax2; \ dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); \ dMULTIPLY0_331 (ax2,joint->node[1].body->posr.R,joint->axis2); \ dCROSS (axis,=,ax1,ax2); \ sin_angle = dSqrt (axis[0]*axis[0] + axis[1]*axis[1] + axis[2]*axis[2]); \ cos_angle = dDOT (ax1,ax2); static void hinge2GetInfo2 (dxJointHinge2 *joint, dxJoint::Info2 *info) { // get information we need to set the hinge row dReal s,c; dVector3 q; HINGE2_GET_AXIS_INFO (q,s,c); dNormalize3 (q); // @@@ quicker: divide q by s ? // set the three ball-and-socket rows (aligned to the suspension axis ax1) setBall2 (joint,info,joint->anchor1,joint->anchor2,ax1,joint->susp_erp); // set the hinge row int s3=3*info->rowskip; info->J1a[s3+0] = q[0]; info->J1a[s3+1] = q[1]; info->J1a[s3+2] = q[2]; if (joint->node[1].body) { info->J2a[s3+0] = -q[0]; info->J2a[s3+1] = -q[1]; info->J2a[s3+2] = -q[2]; } // compute the right hand side for the constrained rotational DOF. // axis 1 and axis 2 are separated by an angle `theta'. the desired // separation angle is theta0. sin(theta0) and cos(theta0) are recorded // in the joint structure. the correcting angular velocity is: // |angular_velocity| = angle/time = erp*(theta0-theta) / stepsize // = (erp*fps) * (theta0-theta) // (theta0-theta) can be computed using the following small-angle-difference // approximation: // theta0-theta ~= tan(theta0-theta) // = sin(theta0-theta)/cos(theta0-theta) // = (c*s0 - s*c0) / (c*c0 + s*s0) // = c*s0 - s*c0 assuming c*c0 + s*s0 ~= 1 // where c = cos(theta), s = sin(theta) // c0 = cos(theta0), s0 = sin(theta0) dReal k = info->fps * info->erp; info->c[3] = k * (joint->c0 * s - joint->s0 * c); // if the axis1 hinge is powered, or has joint limits, add in more stuff int row = 4 + joint->limot1.addLimot (joint,info,4,ax1,1); // if the axis2 hinge is powered, add in more stuff joint->limot2.addLimot (joint,info,row,ax2,1); // set parameter for the suspension info->cfm[0] = joint->susp_cfm; } // compute vectors v1 and v2 (embedded in body1), used to measure angle // between body 1 and body 2 static void makeHinge2V1andV2 (dxJointHinge2 *joint) { if (joint->node[0].body) { // get axis 1 and 2 in global coords dVector3 ax1,ax2,v; dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); dMULTIPLY0_331 (ax2,joint->node[1].body->posr.R,joint->axis2); // don't do anything if the axis1 or axis2 vectors are zero or the same if ((ax1[0]==0 && ax1[1]==0 && ax1[2]==0) || (ax2[0]==0 && ax2[1]==0 && ax2[2]==0) || (ax1[0]==ax2[0] && ax1[1]==ax2[1] && ax1[2]==ax2[2])) return; // modify axis 2 so it's perpendicular to axis 1 dReal k = dDOT(ax1,ax2); for (int i=0; i<3; i++) ax2[i] -= k*ax1[i]; dNormalize3 (ax2); // make v1 = modified axis2, v2 = axis1 x (modified axis2) dCROSS (v,=,ax1,ax2); dMULTIPLY1_331 (joint->v1,joint->node[0].body->posr.R,ax2); dMULTIPLY1_331 (joint->v2,joint->node[0].body->posr.R,v); } } void dJointSetHinge2Anchor (dJointID j, dReal x, dReal y, dReal z) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); setAnchors (joint,x,y,z,joint->anchor1,joint->anchor2); makeHinge2V1andV2 (joint); } void dJointSetHinge2Axis1 (dJointID j, dReal x, dReal y, dReal z) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->node[0].body) { dReal q[4]; q[0] = x; q[1] = y; q[2] = z; q[3] = 0; dNormalize3 (q); dMULTIPLY1_331 (joint->axis1,joint->node[0].body->posr.R,q); joint->axis1[3] = 0; // compute the sin and cos of the angle between axis 1 and axis 2 dVector3 ax; HINGE2_GET_AXIS_INFO(ax,joint->s0,joint->c0); } makeHinge2V1andV2 (joint); } void dJointSetHinge2Axis2 (dJointID j, dReal x, dReal y, dReal z) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->node[1].body) { dReal q[4]; q[0] = x; q[1] = y; q[2] = z; q[3] = 0; dNormalize3 (q); dMULTIPLY1_331 (joint->axis2,joint->node[1].body->posr.R,q); joint->axis1[3] = 0; // compute the sin and cos of the angle between axis 1 and axis 2 dVector3 ax; HINGE2_GET_AXIS_INFO(ax,joint->s0,joint->c0); } makeHinge2V1andV2 (joint); } void dJointSetHinge2Param (dJointID j, int parameter, dReal value) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if ((parameter & 0xff00) == 0x100) { joint->limot2.set (parameter & 0xff,value); } else { if (parameter == dParamSuspensionERP) joint->susp_erp = value; else if (parameter == dParamSuspensionCFM) joint->susp_cfm = value; else joint->limot1.set (parameter,value); } } void dJointGetHinge2Anchor (dJointID j, dVector3 result) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->flags & dJOINT_REVERSE) getAnchor2 (joint,result,joint->anchor2); else getAnchor (joint,result,joint->anchor1); } void dJointGetHinge2Anchor2 (dJointID j, dVector3 result) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->flags & dJOINT_REVERSE) getAnchor (joint,result,joint->anchor1); else getAnchor2 (joint,result,joint->anchor2); } void dJointGetHinge2Axis1 (dJointID j, dVector3 result) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->node[0].body) { dMULTIPLY0_331 (result,joint->node[0].body->posr.R,joint->axis1); } } void dJointGetHinge2Axis2 (dJointID j, dVector3 result) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->node[1].body) { dMULTIPLY0_331 (result,joint->node[1].body->posr.R,joint->axis2); } } dReal dJointGetHinge2Param (dJointID j, int parameter) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if ((parameter & 0xff00) == 0x100) { return joint->limot2.get (parameter & 0xff); } else { if (parameter == dParamSuspensionERP) return joint->susp_erp; else if (parameter == dParamSuspensionCFM) return joint->susp_cfm; else return joint->limot1.get (parameter); } } dReal dJointGetHinge2Angle1 (dJointID j) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->node[0].body) return measureHinge2Angle (joint); else return 0; } dReal dJointGetHinge2Angle1Rate (dJointID j) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->node[0].body) { dVector3 axis; dMULTIPLY0_331 (axis,joint->node[0].body->posr.R,joint->axis1); dReal rate = dDOT(axis,joint->node[0].body->avel); if (joint->node[1].body) rate -= dDOT(axis,joint->node[1].body->avel); return rate; } else return 0; } dReal dJointGetHinge2Angle2Rate (dJointID j) { dxJointHinge2* joint = (dxJointHinge2*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->node[0].body && joint->node[1].body) { dVector3 axis; dMULTIPLY0_331 (axis,joint->node[1].body->posr.R,joint->axis2); dReal rate = dDOT(axis,joint->node[0].body->avel); if (joint->node[1].body) rate -= dDOT(axis,joint->node[1].body->avel); return rate; } else return 0; } void dJointAddHinge2Torques (dJointID j, dReal torque1, dReal torque2) { dxJointHinge2* joint = (dxJointHinge2*)j; dVector3 axis1, axis2; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dhinge2_vtable,"joint is not a hinge2"); if (joint->node[0].body && joint->node[1].body) { dMULTIPLY0_331 (axis1,joint->node[0].body->posr.R,joint->axis1); dMULTIPLY0_331 (axis2,joint->node[1].body->posr.R,joint->axis2); axis1[0] = axis1[0] * torque1 + axis2[0] * torque2; axis1[1] = axis1[1] * torque1 + axis2[1] * torque2; axis1[2] = axis1[2] * torque1 + axis2[2] * torque2; dBodyAddTorque (joint->node[0].body,axis1[0],axis1[1],axis1[2]); dBodyAddTorque(joint->node[1].body, -axis1[0], -axis1[1], -axis1[2]); } } dxJoint::Vtable __dhinge2_vtable = { sizeof(dxJointHinge2), (dxJoint::init_fn*) hinge2Init, (dxJoint::getInfo1_fn*) hinge2GetInfo1, (dxJoint::getInfo2_fn*) hinge2GetInfo2, dJointTypeHinge2}; //**************************************************************************** // universal // I just realized that the universal joint is equivalent to a hinge 2 joint with // perfectly stiff suspension. By comparing the hinge 2 implementation to // the universal implementation, you may be able to improve this // implementation (or, less likely, the hinge2 implementation). static void universalInit (dxJointUniversal *j) { dSetZero (j->anchor1,4); dSetZero (j->anchor2,4); dSetZero (j->axis1,4); j->axis1[0] = 1; dSetZero (j->axis2,4); j->axis2[1] = 1; dSetZero(j->qrel1,4); dSetZero(j->qrel2,4); j->limot1.init (j->world); j->limot2.init (j->world); } static void getUniversalAxes(dxJointUniversal *joint, dVector3 ax1, dVector3 ax2) { // This says "ax1 = joint->node[0].body->posr.R * joint->axis1" dMULTIPLY0_331 (ax1,joint->node[0].body->posr.R,joint->axis1); if (joint->node[1].body) { dMULTIPLY0_331 (ax2,joint->node[1].body->posr.R,joint->axis2); } else { ax2[0] = joint->axis2[0]; ax2[1] = joint->axis2[1]; ax2[2] = joint->axis2[2]; } } static void getUniversalAngles(dxJointUniversal *joint, dReal *angle1, dReal *angle2) { if (joint->node[0].body) { // length 1 joint axis in global coordinates, from each body dVector3 ax1, ax2; dMatrix3 R; dQuaternion qcross, qq, qrel; getUniversalAxes (joint,ax1,ax2); // It should be possible to get both angles without explicitly // constructing the rotation matrix of the cross. Basically, // orientation of the cross about axis1 comes from body 2, // about axis 2 comes from body 1, and the perpendicular // axis can come from the two bodies somehow. (We don't really // want to assume it's 90 degrees, because in general the // constraints won't be perfectly satisfied, or even very well // satisfied.) // // However, we'd need a version of getHingeAngleFromRElativeQuat() // that CAN handle when its relative quat is rotated along a direction // other than the given axis. What I have here works, // although it's probably much slower than need be. dRFrom2Axes (R, ax1[0], ax1[1], ax1[2], ax2[0], ax2[1], ax2[2]); dRtoQ (R, qcross); // This code is essentialy the same as getHingeAngle(), see the comments // there for details. // get qrel = relative rotation between node[0] and the cross dQMultiply1 (qq, joint->node[0].body->q, qcross); dQMultiply2 (qrel, qq, joint->qrel1); *angle1 = getHingeAngleFromRelativeQuat(qrel, joint->axis1); // This is equivalent to // dRFrom2Axes(R, ax2[0], ax2[1], ax2[2], ax1[0], ax1[1], ax1[2]); // You see that the R is constructed from the same 2 axis as for angle1 // but the first and second axis are swapped. // So we can take the first R and rapply a rotation to it. // The rotation is around the axis between the 2 axes (ax1 and ax2). // We do a rotation of 180deg. dQuaternion qcross2; // Find the vector between ax1 and ax2 (i.e. in the middle) // We need to turn around this vector by 180deg // The 2 axes should be normalize so to find the vector between the 2. // Add and devide by 2 then normalize or simply normalize // ax2 // ^ // | // | /// *------------> ax1 // We want the vector a 45deg // // N.B. We don't need to normalize the ax1 and ax2 since there are // normalized when we set them. // We set the quaternion q = [cos(theta), dir*sin(theta)] = [w, x, y, Z] qrel[0] = 0; // equivalent to cos(Pi/2) qrel[1] = ax1[0] + ax2[0]; // equivalent to x*sin(Pi/2); since sin(Pi/2) = 1 qrel[2] = ax1[1] + ax2[1]; qrel[3] = ax1[2] + ax2[2]; dReal l = dRecip(sqrt(qrel[1]*qrel[1] + qrel[2]*qrel[2] + qrel[3]*qrel[3])); qrel[1] *= l; qrel[2] *= l; qrel[3] *= l; dQMultiply0 (qcross2, qrel, qcross); if (joint->node[1].body) { dQMultiply1 (qq, joint->node[1].body->q, qcross2); dQMultiply2 (qrel, qq, joint->qrel2); } else { // pretend joint->node[1].body->q is the identity dQMultiply2 (qrel, qcross2, joint->qrel2); } *angle2 = - getHingeAngleFromRelativeQuat(qrel, joint->axis2); } else { *angle1 = 0; *angle2 = 0; } } static dReal getUniversalAngle1(dxJointUniversal *joint) { if (joint->node[0].body) { // length 1 joint axis in global coordinates, from each body dVector3 ax1, ax2; dMatrix3 R; dQuaternion qcross, qq, qrel; getUniversalAxes (joint,ax1,ax2); // It should be possible to get both angles without explicitly // constructing the rotation matrix of the cross. Basically, // orientation of the cross about axis1 comes from body 2, // about axis 2 comes from body 1, and the perpendicular // axis can come from the two bodies somehow. (We don't really // want to assume it's 90 degrees, because in general the // constraints won't be perfectly satisfied, or even very well // satisfied.) // // However, we'd need a version of getHingeAngleFromRElativeQuat() // that CAN handle when its relative quat is rotated along a direction // other than the given axis. What I have here works, // although it's probably much slower than need be. dRFrom2Axes(R, ax1[0], ax1[1], ax1[2], ax2[0], ax2[1], ax2[2]); dRtoQ (R,qcross); // This code is essential the same as getHingeAngle(), see the comments // there for details. // get qrel = relative rotation between node[0] and the cross dQMultiply1 (qq,joint->node[0].body->q,qcross); dQMultiply2 (qrel,qq,joint->qrel1); return getHingeAngleFromRelativeQuat(qrel, joint->axis1); } return 0; } static dReal getUniversalAngle2(dxJointUniversal *joint) { if (joint->node[0].body) { // length 1 joint axis in global coordinates, from each body dVector3 ax1, ax2; dMatrix3 R; dQuaternion qcross, qq, qrel; getUniversalAxes (joint,ax1,ax2); // It should be possible to get both angles without explicitly // constructing the rotation matrix of the cross. Basically, // orientation of the cross about axis1 comes from body 2, // about axis 2 comes from body 1, and the perpendicular // axis can come from the two bodies somehow. (We don't really // want to assume it's 90 degrees, because in general the // constraints won't be perfectly satisfied, or even very well // satisfied.) // // However, we'd need a version of getHingeAngleFromRElativeQuat() // that CAN handle when its relative quat is rotated along a direction // other than the given axis. What I have here works, // although it's probably much slower than need be. dRFrom2Axes(R, ax2[0], ax2[1], ax2[2], ax1[0], ax1[1], ax1[2]); dRtoQ(R, qcross); if (joint->node[1].body) { dQMultiply1 (qq, joint->node[1].body->q, qcross); dQMultiply2 (qrel,qq,joint->qrel2); } else { // pretend joint->node[1].body->q is the identity dQMultiply2 (qrel,qcross, joint->qrel2); } return - getHingeAngleFromRelativeQuat(qrel, joint->axis2); } return 0; } static void universalGetInfo1 (dxJointUniversal *j, dxJoint::Info1 *info) { info->nub = 4; info->m = 4; // see if we're powered or at a joint limit. bool constraint1 = j->limot1.fmax > 0; bool constraint2 = j->limot2.fmax > 0; bool limiting1 = (j->limot1.lostop >= -M_PI || j->limot1.histop <= M_PI) && j->limot1.lostop <= j->limot1.histop; bool limiting2 = (j->limot2.lostop >= -M_PI || j->limot2.histop <= M_PI) && j->limot2.lostop <= j->limot2.histop; // We need to call testRotationLimit() even if we're motored, since it // records the result. if (limiting1 || limiting2) { dReal angle1, angle2; getUniversalAngles (j, &angle1, &angle2); if (limiting1 && j->limot1.testRotationalLimit (angle1)) constraint1 = true; if (limiting2 && j->limot2.testRotationalLimit (angle2)) constraint2 = true; } if (constraint1) info->m++; if (constraint2) info->m++; } static void universalGetInfo2 (dxJointUniversal *joint, dxJoint::Info2 *info) { // set the three ball-and-socket rows setBall (joint,info,joint->anchor1,joint->anchor2); // set the universal joint row. the angular velocity about an axis // perpendicular to both joint axes should be equal. thus the constraint // equation is // p*w1 - p*w2 = 0 // where p is a vector normal to both joint axes, and w1 and w2 // are the angular velocity vectors of the two bodies. // length 1 joint axis in global coordinates, from each body dVector3 ax1, ax2; dVector3 ax2_temp; // length 1 vector perpendicular to ax1 and ax2. Neither body can rotate // about this. dVector3 p; dReal k; getUniversalAxes(joint, ax1, ax2); k = dDOT(ax1, ax2); ax2_temp[0] = ax2[0] - k*ax1[0]; ax2_temp[1] = ax2[1] - k*ax1[1]; ax2_temp[2] = ax2[2] - k*ax1[2]; dCROSS(p, =, ax1, ax2_temp); dNormalize3(p); int s3=3*info->rowskip; info->J1a[s3+0] = p[0]; info->J1a[s3+1] = p[1]; info->J1a[s3+2] = p[2]; if (joint->node[1].body) { info->J2a[s3+0] = -p[0]; info->J2a[s3+1] = -p[1]; info->J2a[s3+2] = -p[2]; } // compute the right hand side of the constraint equation. set relative // body velocities along p to bring the axes back to perpendicular. // If ax1, ax2 are unit length joint axes as computed from body1 and // body2, we need to rotate both bodies along the axis p. If theta // is the angle between ax1 and ax2, we need an angular velocity // along p to cover the angle erp * (theta - Pi/2) in one step: // // |angular_velocity| = angle/time = erp*(theta - Pi/2) / stepsize // = (erp*fps) * (theta - Pi/2) // // if theta is close to Pi/2, // theta - Pi/2 ~= cos(theta), so // |angular_velocity| ~= (erp*fps) * (ax1 dot ax2) info->c[3] = info->fps * info->erp * - dDOT(ax1, ax2); // if the first angle is powered, or has joint limits, add in the stuff int row = 4 + joint->limot1.addLimot (joint,info,4,ax1,1); // if the second angle is powered, or has joint limits, add in more stuff joint->limot2.addLimot (joint,info,row,ax2,1); } static void universalComputeInitialRelativeRotations (dxJointUniversal *joint) { if (joint->node[0].body) { dVector3 ax1, ax2; dMatrix3 R; dQuaternion qcross; getUniversalAxes(joint, ax1, ax2); // Axis 1. dRFrom2Axes(R, ax1[0], ax1[1], ax1[2], ax2[0], ax2[1], ax2[2]); dRtoQ(R, qcross); dQMultiply1 (joint->qrel1, joint->node[0].body->q, qcross); // Axis 2. dRFrom2Axes(R, ax2[0], ax2[1], ax2[2], ax1[0], ax1[1], ax1[2]); dRtoQ(R, qcross); if (joint->node[1].body) { dQMultiply1 (joint->qrel2, joint->node[1].body->q, qcross); } else { // set joint->qrel to qcross for (int i=0; i<4; i++) joint->qrel2[i] = qcross[i]; } } } void dJointSetUniversalAnchor (dJointID j, dReal x, dReal y, dReal z) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); setAnchors (joint,x,y,z,joint->anchor1,joint->anchor2); universalComputeInitialRelativeRotations(joint); } void dJointSetUniversalAxis1 (dJointID j, dReal x, dReal y, dReal z) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) setAxes (joint,x,y,z,NULL,joint->axis2); else setAxes (joint,x,y,z,joint->axis1,NULL); universalComputeInitialRelativeRotations(joint); } void dJointSetUniversalAxis2 (dJointID j, dReal x, dReal y, dReal z) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) setAxes (joint,x,y,z,joint->axis1,NULL); else setAxes (joint,x,y,z,NULL,joint->axis2); universalComputeInitialRelativeRotations(joint); } void dJointGetUniversalAnchor (dJointID j, dVector3 result) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) getAnchor2 (joint,result,joint->anchor2); else getAnchor (joint,result,joint->anchor1); } void dJointGetUniversalAnchor2 (dJointID j, dVector3 result) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) getAnchor (joint,result,joint->anchor1); else getAnchor2 (joint,result,joint->anchor2); } void dJointGetUniversalAxis1 (dJointID j, dVector3 result) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) getAxis2 (joint,result,joint->axis2); else getAxis (joint,result,joint->axis1); } void dJointGetUniversalAxis2 (dJointID j, dVector3 result) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) getAxis (joint,result,joint->axis1); else getAxis2 (joint,result,joint->axis2); } void dJointSetUniversalParam (dJointID j, int parameter, dReal value) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if ((parameter & 0xff00) == 0x100) { joint->limot2.set (parameter & 0xff,value); } else { joint->limot1.set (parameter,value); } } dReal dJointGetUniversalParam (dJointID j, int parameter) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if ((parameter & 0xff00) == 0x100) { return joint->limot2.get (parameter & 0xff); } else { return joint->limot1.get (parameter); } } void dJointGetUniversalAngles (dJointID j, dReal *angle1, dReal *angle2) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) return getUniversalAngles (joint, angle2, angle1); else return getUniversalAngles (joint, angle1, angle2); } dReal dJointGetUniversalAngle1 (dJointID j) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) return getUniversalAngle2 (joint); else return getUniversalAngle1 (joint); } dReal dJointGetUniversalAngle2 (dJointID j) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) return getUniversalAngle1 (joint); else return getUniversalAngle2 (joint); } dReal dJointGetUniversalAngle1Rate (dJointID j) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->node[0].body) { dVector3 axis; if (joint->flags & dJOINT_REVERSE) getAxis2 (joint,axis,joint->axis2); else getAxis (joint,axis,joint->axis1); dReal rate = dDOT(axis, joint->node[0].body->avel); if (joint->node[1].body) rate -= dDOT(axis, joint->node[1].body->avel); return rate; } return 0; } dReal dJointGetUniversalAngle2Rate (dJointID j) { dxJointUniversal* joint = (dxJointUniversal*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->node[0].body) { dVector3 axis; if (joint->flags & dJOINT_REVERSE) getAxis (joint,axis,joint->axis1); else getAxis2 (joint,axis,joint->axis2); dReal rate = dDOT(axis, joint->node[0].body->avel); if (joint->node[1].body) rate -= dDOT(axis, joint->node[1].body->avel); return rate; } return 0; } void dJointAddUniversalTorques (dJointID j, dReal torque1, dReal torque2) { dxJointUniversal* joint = (dxJointUniversal*)j; dVector3 axis1, axis2; dAASSERT(joint); dUASSERT(joint->vtable == &__duniversal_vtable,"joint is not a universal"); if (joint->flags & dJOINT_REVERSE) { dReal temp = torque1; torque1 = - torque2; torque2 = - temp; } getAxis (joint,axis1,joint->axis1); getAxis2 (joint,axis2,joint->axis2); axis1[0] = axis1[0] * torque1 + axis2[0] * torque2; axis1[1] = axis1[1] * torque1 + axis2[1] * torque2; axis1[2] = axis1[2] * torque1 + axis2[2] * torque2; if (joint->node[0].body != 0) dBodyAddTorque (joint->node[0].body,axis1[0],axis1[1],axis1[2]); if (joint->node[1].body != 0) dBodyAddTorque(joint->node[1].body, -axis1[0], -axis1[1], -axis1[2]); } dxJoint::Vtable __duniversal_vtable = { sizeof(dxJointUniversal), (dxJoint::init_fn*) universalInit, (dxJoint::getInfo1_fn*) universalGetInfo1, (dxJoint::getInfo2_fn*) universalGetInfo2, dJointTypeUniversal}; //**************************************************************************** // Prismatic and Rotoide static void PRInit (dxJointPR *j) { // Default Position // Z^ // | Body 1 P R Body2 // |+---------+ _ _ +-----------+ // || |----|----(_)--------+ | // |+---------+ - +-----------+ // | // X.-----------------------------------------> Y // N.B. X is comming out of the page dSetZero (j->anchor2,4); dSetZero (j->axisR1,4); j->axisR1[0] = 1; dSetZero (j->axisR2,4); j->axisR2[0] = 1; dSetZero (j->axisP1,4); j->axisP1[1] = 1; dSetZero (j->qrel,4); dSetZero (j->offset,4); dSetZero (j->prev,4); j->limotR.init (j->world); j->limotP.init (j->world); } dReal dJointGetPRPosition (dJointID j) { dxJointPR* joint = (dxJointPR*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); dVector3 q; // get the offset in global coordinates dMULTIPLY0_331 (q,joint->node[0].body->posr.R,joint->offset); if (joint->node[1].body) { dVector3 anchor2; // get the anchor2 in global coordinates dMULTIPLY0_331 (anchor2,joint->node[1].body->posr.R,joint->anchor2); q[0] = ( (joint->node[0].body->posr.pos[0] + q[0]) - (joint->node[1].body->posr.pos[0] + anchor2[0]) ); q[1] = ( (joint->node[0].body->posr.pos[1] + q[1]) - (joint->node[1].body->posr.pos[1] + anchor2[1]) ); q[2] = ( (joint->node[0].body->posr.pos[2] + q[2]) - (joint->node[1].body->posr.pos[2] + anchor2[2]) ); } else { //N.B. When there is no body 2 the joint->anchor2 is already in // global coordinates q[0] = ( (joint->node[0].body->posr.pos[0] + q[0]) - (joint->anchor2[0]) ); q[1] = ( (joint->node[0].body->posr.pos[1] + q[1]) - (joint->anchor2[1]) ); q[2] = ( (joint->node[0].body->posr.pos[2] + q[2]) - (joint->anchor2[2]) ); } dVector3 axP; // get prismatic axis in global coordinates dMULTIPLY0_331 (axP,joint->node[0].body->posr.R,joint->axisP1); return dDOT(axP, q); } dReal dJointGetPRPositionRate (dJointID j) { dxJointPR* joint = (dxJointPR*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); if (joint->node[0].body) { // We want to find the rate of change of the prismatic part of the joint // We can find it by looking at the speed difference between body1 and the // anchor point. // r will be used to find the distance between body1 and the anchor point dVector3 r; if (joint->node[1].body) { // Find joint->anchor2 in global coordinates dVector3 anchor2; dMULTIPLY0_331 (anchor2,joint->node[1].body->posr.R,joint->anchor2); r[0] = joint->node[0].body->posr.pos[0] - anchor2[0]; r[1] = joint->node[0].body->posr.pos[1] - anchor2[1]; r[2] = joint->node[0].body->posr.pos[2] - anchor2[2]; } else { //N.B. When there is no body 2 the joint->anchor2 is already in // global coordinates r[0] = joint->node[0].body->posr.pos[0] - joint->anchor2[0]; r[1] = joint->node[0].body->posr.pos[1] - joint->anchor2[1]; r[2] = joint->node[0].body->posr.pos[2] - joint->anchor2[2]; } // The body1 can have velocity coming from the rotation of // the rotoide axis. We need to remove this. // Take only the angular rotation coming from the rotation // of the rotoide articulation // N.B. Body1 and Body2 should have the same rotation along axis // other than the rotoide axis. dVector3 angular; dMULTIPLY0_331 (angular,joint->node[0].body->posr.R,joint->axisR1); dReal omega = dDOT(angular, joint->node[0].body->avel); angular[0] *= omega; angular[1] *= omega; angular[2] *= omega; // Find the contribution of the angular rotation to the linear speed // N.B. We do vel = r X w instead of vel = w x r to have vel negative // since we want to remove it from the linear velocity of the body dVector3 lvel1; dCROSS(lvel1, =, r, angular); lvel1[0] += joint->node[0].body->lvel[0]; lvel1[1] += joint->node[0].body->lvel[1]; lvel1[2] += joint->node[0].body->lvel[2]; // Since we want rate of change along the prismatic axis // get axisP1 in global coordinates and get the component // along this axis only dVector3 axP1; dMULTIPLY0_331 (axP1,joint->node[0].body->posr.R,joint->axisP1); return dDOT(axP1, lvel1); } return 0.0; } static void PRGetInfo1 (dxJointPR *j, dxJoint::Info1 *info) { info->m = 4; info->nub = 4; bool added = false; added = false; // see if the prismatic articulation is powered if (j->limotP.fmax > 0) { added = true; (info->m)++; // powered needs an extra constraint row } // see if we're at a joint limit. j->limotP.limit = 0; if ((j->limotP.lostop > -dInfinity || j->limotP.histop < dInfinity) && j->limotP.lostop <= j->limotP.histop) { // measure joint position dReal pos = dJointGetPRPosition (j); if (pos <= j->limotP.lostop) { j->limotP.limit = 1; j->limotP.limit_err = pos - j->limotP.lostop; if (!added) (info->m)++; } if (pos >= j->limotP.histop) { j->limotP.limit = 2; j->limotP.limit_err = pos - j->limotP.histop; if (!added) (info->m)++; } } } static void PRGetInfo2 (dxJointPR *joint, dxJoint::Info2 *info) { int i; int s = info->rowskip; int s2= 2*s; int s3= 3*s; int s4= 4*s; dReal k = info->fps * info->erp; dVector3 q; // plane space of axP and after that axR // pull out pos and R for both bodies. also get the `connection' // vector pos2-pos1. dReal *pos1,*pos2,*R1,*R2; pos1 = joint->node[0].body->posr.pos; R1 = joint->node[0].body->posr.R; if (joint->node[1].body) { pos2 = joint->node[1].body->posr.pos; R2 = joint->node[1].body->posr.R; } else { // pos2 = 0; // N.B. We can do that to be safe but it is no necessary // R2 = 0; // N.B. We can do that to be safe but it is no necessary } dVector3 axP; // Axis of the prismatic joint in global frame dMULTIPLY0_331 (axP, R1, joint->axisP1); // distance between the body1 and the anchor2 in global frame // Calculated in the same way as the offset dVector3 dist; if (joint->node[1].body) { dMULTIPLY0_331 (dist, R2, joint->anchor2); dist[0] += pos2[0] - pos1[0]; dist[1] += pos2[1] - pos1[1]; dist[2] += pos2[2] - pos1[2]; } else { dist[0] = joint->anchor2[0] - pos1[0]; dist[1] = joint->anchor2[1] - pos1[1]; dist[2] = joint->anchor2[2] - pos1[2]; } // ====================================================================== // Work on the Rotoide part (i.e. row 0, 1 and maybe 4 if rotoide powered // Set the two rotoide rows. The rotoide axis should be the only unconstrained // rotational axis, the angular velocity of the two bodies perpendicular to // the rotoide axis should be equal. Thus the constraint equations are // p*w1 - p*w2 = 0 // q*w1 - q*w2 = 0 // where p and q are unit vectors normal to the rotoide axis, and w1 and w2 // are the angular velocity vectors of the two bodies. dVector3 ax1; dMULTIPLY0_331 (ax1, joint->node[0].body->posr.R, joint->axisR1); dCROSS(q , =, ax1, axP); info->J1a[0] = axP[0]; info->J1a[1] = axP[1]; info->J1a[2] = axP[2]; info->J1a[s+0] = q[0]; info->J1a[s+1] = q[1]; info->J1a[s+2] = q[2]; if (joint->node[1].body) { info->J2a[0] = -axP[0]; info->J2a[1] = -axP[1]; info->J2a[2] = -axP[2]; info->J2a[s+0] = -q[0]; info->J2a[s+1] = -q[1]; info->J2a[s+2] = -q[2]; } // Compute the right hand side of the constraint equation set. Relative // body velocities along p and q to bring the hinge back into alignment. // ax1,ax2 are the unit length rotoide axes of body1 and body2 in world frame. // We need to rotate both bodies along the axis u = (ax1 x ax2). // if `theta' is the angle between ax1 and ax2, we need an angular velocity // along u to cover angle erp*theta in one step : // |angular_velocity| = angle/time = erp*theta / stepsize // = (erp*fps) * theta // angular_velocity = |angular_velocity| * (ax1 x ax2) / |ax1 x ax2| // = (erp*fps) * theta * (ax1 x ax2) / sin(theta) // ...as ax1 and ax2 are unit length. if theta is smallish, // theta ~= sin(theta), so // angular_velocity = (erp*fps) * (ax1 x ax2) // ax1 x ax2 is in the plane space of ax1, so we project the angular // velocity to p and q to find the right hand side. dVector3 ax2; if (joint->node[1].body) { dMULTIPLY0_331 (ax2, R2, joint->axisR2); } else { ax2[0] = joint->axisR2[0]; ax2[1] = joint->axisR2[1]; ax2[2] = joint->axisR2[2]; } dVector3 b; dCROSS (b,=,ax1, ax2); info->c[0] = k * dDOT(b, axP); info->c[1] = k * dDOT(b, q); // ========================== // Work on the Prismatic part (i.e row 2,3 and 4 if only the prismatic is powered // or 5 if rotoide and prismatic powered // two rows. we want: vel2 = vel1 + w1 x c ... but this would // result in three equations, so we project along the planespace vectors // so that sliding along the prismatic axis is disregarded. for symmetry we // also substitute (w1+w2)/2 for w1, as w1 is supposed to equal w2. // p1 + R1 dist' = p2 + R2 anchor2' ## OLD ## p1 + R1 anchor1' = p2 + R2 dist' // v1 + w1 x R1 dist' + v_p = v2 + w2 x R2 anchor2'## OLD v1 + w1 x R1 anchor1' = v2 + w2 x R2 dist' + v_p // v_p is speed of prismatic joint (i.e. elongation rate) // Since the constraints are perpendicular to v_p we have: // p dot v_p = 0 and q dot v_p = 0 // ax1 dot ( v1 + w1 x dist = v2 + w2 x anchor2 ) // q dot ( v1 + w1 x dist = v2 + w2 x anchor2 ) // == // ax1 . v1 + ax1 . w1 x dist = ax1 . v2 + ax1 . w2 x anchor2 ## OLD ## ax1 . v1 + ax1 . w1 x anchor1 = ax1 . v2 + ax1 . w2 x dist // since a . (b x c) = - b . (a x c) = - (a x c) . b // and a x b = - b x a // ax1 . v1 - ax1 x dist . w1 - ax1 . v2 - (- ax1 x anchor2 . w2) = 0 // ax1 . v1 + dist x ax1 . w1 - ax1 . v2 - anchor2 x ax1 . w2 = 0 // Coeff for 1er line of: J1l => ax1, J2l => -ax1 // Coeff for 2er line of: J1l => q, J2l => -q // Coeff for 1er line of: J1a => dist x ax1, J2a => - anchor2 x ax1 // Coeff for 2er line of: J1a => dist x q, J2a => - anchor2 x q dCROSS ((info->J1a)+s2, = , dist, ax1); dCROSS ((info->J1a)+s3, = , dist, q); info->J1l[s2+0] = ax1[0]; info->J1l[s2+1] = ax1[1]; info->J1l[s2+2] = ax1[2]; info->J1l[s3+0] = q[0]; info->J1l[s3+1] = q[1]; info->J1l[s3+2] = q[2]; dVector3 anchor2; if (joint->node[1].body) { // Calculate anchor2 in world coordinate dMULTIPLY0_331 (anchor2, R2, joint->anchor2); // ax2 x anchor2 instead of anchor2 x ax2 since we want the negative value dCROSS ((info->J2a)+s2, = , ax2, anchor2); // since ax1 == ax2 // The cross product is in reverse order since we want the negative value dCROSS ((info->J2a)+s3, = , q, anchor2); info->J2l[s2+0] = -ax1[0]; info->J2l[s2+1] = -ax1[1]; info->J2l[s2+2] = -ax1[2]; info->J2l[s3+0] = -q[0]; info->J2l[s3+1] = -q[1]; info->J2l[s3+2] = -q[2]; } else { anchor2[0] = joint->anchor2[0]; anchor2[1] = joint->anchor2[1]; anchor2[2] = joint->anchor2[2]; } // We want to make correction for motion not in the line of the axisP // We calculate the displacement w.r.t. the anchor pt. // // compute the elements 2 and 3 of right hand side. // we want to align the offset point (in body 2's frame) with the center of body 1. // The position should be the same when we are not along the prismatic axis dVector3 err; dMULTIPLY0_331 (err, R1, joint->offset); err[0] += dist[0]; err[1] += dist[1]; err[2] += dist[2]; info->c[2] = k * dDOT(ax1, err); info->c[3] = k * dDOT(q, err); // Here we can't use addLimot because of some assumption in the function int powered = joint->limotP.fmax > 0; if (powered || joint->limotP.limit) { info->J1l[s4+0] = axP[0]; info->J1l[s4+1] = axP[1]; info->J1l[s4+2] = axP[2]; if (joint->node[1].body) { info->J2l[s4+0] = -axP[0]; info->J2l[s4+1] = -axP[1]; info->J2l[s4+2] = -axP[2]; } // linear limot torque decoupling step: // // if this is a linear limot (e.g. from a slider), we have to be careful // that the linear constraint forces (+/- ax1) applied to the two bodies // do not create a torque couple. in other words, the points that the // constraint force is applied at must lie along the same ax1 axis. // a torque couple will result in powered or limited slider-jointed free // bodies from gaining angular momentum. // the solution used here is to apply the constraint forces at the point // halfway between the body centers. there is no penalty (other than an // extra tiny bit of computation) in doing this adjustment. note that we // only need to do this if the constraint connects two bodies. dVector3 ltd; // Linear Torque Decoupling vector (a torque) if (joint->node[1].body) { dVector3 c; c[0]=REAL(0.5)*(joint->node[1].body->posr.pos[0]-joint->node[0].body->posr.pos[0]); c[1]=REAL(0.5)*(joint->node[1].body->posr.pos[1]-joint->node[0].body->posr.pos[1]); c[2]=REAL(0.5)*(joint->node[1].body->posr.pos[2]-joint->node[0].body->posr.pos[2]); dReal val = dDOT(q, c); c[0] -= val * c[0]; c[1] -= val * c[1]; c[2] -= val * c[2]; dCROSS (ltd,=,c,axP); info->J1a[s4+0] = ltd[0]; info->J1a[s4+1] = ltd[1]; info->J1a[s4+2] = ltd[2]; info->J2a[s4+0] = ltd[0]; info->J2a[s4+1] = ltd[1]; info->J2a[s4+2] = ltd[2]; } // if we're limited low and high simultaneously, the joint motor is // ineffective if (joint->limotP.limit && (joint->limotP.lostop == joint->limotP.histop)) powered = 0; int row = 4; if (powered) { info->cfm[row] = joint->limotP.normal_cfm; if (!joint->limotP.limit) { info->c[row] = joint->limotP.vel; info->lo[row] = -joint->limotP.fmax; info->hi[row] = joint->limotP.fmax; } else { // the joint is at a limit, AND is being powered. if the joint is // being powered into the limit then we apply the maximum motor force // in that direction, because the motor is working against the // immovable limit. if the joint is being powered away from the limit // then we have problems because actually we need *two* lcp // constraints to handle this case. so we fake it and apply some // fraction of the maximum force. the fraction to use can be set as // a fudge factor. dReal fm = joint->limotP.fmax; dReal vel = joint->limotP.vel; int limit = joint->limotP.limit; if ((vel > 0) || (vel==0 && limit==2)) fm = -fm; // if we're powering away from the limit, apply the fudge factor if ((limit==1 && vel > 0) || (limit==2 && vel < 0)) fm *= joint->limotP.fudge_factor; dBodyAddForce (joint->node[0].body,-fm*axP[0],-fm*axP[1],-fm*axP[2]); if (joint->node[1].body) { dBodyAddForce (joint->node[1].body,fm*axP[0],fm*axP[1],fm*axP[2]); // linear limot torque decoupling step: refer to above discussion dBodyAddTorque (joint->node[0].body,-fm*ltd[0],-fm*ltd[1], -fm*ltd[2]); dBodyAddTorque (joint->node[1].body,-fm*ltd[0],-fm*ltd[1], -fm*ltd[2]); } } } if (joint->limotP.limit) { dReal k = info->fps * joint->limotP.stop_erp; info->c[row] = -k * joint->limotP.limit_err; info->cfm[row] = joint->limotP.stop_cfm; if (joint->limotP.lostop == joint->limotP.histop) { // limited low and high simultaneously info->lo[row] = -dInfinity; info->hi[row] = dInfinity; } else { if (joint->limotP.limit == 1) { // low limit info->lo[row] = 0; info->hi[row] = dInfinity; } else { // high limit info->lo[row] = -dInfinity; info->hi[row] = 0; } // deal with bounce if (joint->limotP.bounce > 0) { // calculate joint velocity dReal vel; vel = dDOT(joint->node[0].body->lvel, axP); if (joint->node[1].body) vel -= dDOT(joint->node[1].body->lvel, axP); // only apply bounce if the velocity is incoming, and if the // resulting c[] exceeds what we already have. if (joint->limotP.limit == 1) { // low limit if (vel < 0) { dReal newc = -joint->limotP.bounce * vel; if (newc > info->c[row]) info->c[row] = newc; } } else { // high limit - all those computations are reversed if (vel > 0) { dReal newc = -joint->limotP.bounce * vel; if (newc < info->c[row]) info->c[row] = newc; } } } } } } } // compute initial relative rotation body1 -> body2, or env -> body1 static void PRComputeInitialRelativeRotation (dxJointPR *joint) { if (joint->node[0].body) { if (joint->node[1].body) { dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); } else { // set joint->qrel to the transpose of the first body q joint->qrel[0] = joint->node[0].body->q[0]; for (int i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; // WARNING do we need the - in -joint->node[0].body->q[i]; or not } } } void dJointSetPRAnchor (dJointID j, dReal x, dReal y, dReal z) { dxJointPR* joint = (dxJointPR*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); dVector3 dummy; setAnchors (joint,x,y,z,dummy,joint->anchor2); PRComputeInitialRelativeRotation (joint); if (joint->node[1].body) dMULTIPLY0_331 (joint->prev, joint->node[1].body->posr.R,joint->anchor2); else { joint->prev[0] = joint->anchor2[0]; joint->prev[1] = joint->anchor2[1]; joint->prev[2] = joint->anchor2[2]; } } void dJointSetPRAxis1 (dJointID j, dReal x, dReal y, dReal z) { dxJointPR* joint = (dxJointPR*)j; int i; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); setAxes (joint,x,y,z,joint->axisP1, 0); PRComputeInitialRelativeRotation (joint); // compute initial relative rotation body1 -> body2, or env -> body1 // also compute distance between anchor of body1 w.r.t center of body 2 dVector3 c; if (joint->node[1].body) { dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); dVector3 anchor2; dMULTIPLY0_331 (anchor2,joint->node[1].body->posr.R, joint->anchor2); c[0] = ( joint->node[1].body->posr.pos[0] + anchor2[0] - joint->node[0].body->posr.pos[0] ); c[1] = ( joint->node[1].body->posr.pos[1] + anchor2[1] - joint->node[0].body->posr.pos[1] ); c[2] = ( joint->node[1].body->posr.pos[2] + anchor2[2] - joint->node[0].body->posr.pos[2] ); } else if (joint->node[0].body) { // set joint->qrel to the transpose of the first body's q joint->qrel[0] = joint->node[0].body->q[0]; for (i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; c[0] = joint->anchor2[0] - joint->node[0].body->posr.pos[0]; c[1] = joint->anchor2[1] - joint->node[0].body->posr.pos[1]; c[2] = joint->anchor2[2] - joint->node[0].body->posr.pos[2]; } else { joint->offset[0] = joint->anchor2[0]; joint->offset[1] = joint->anchor2[1]; joint->offset[2] = joint->anchor2[2]; return; } dMULTIPLY1_331 (joint->offset,joint->node[0].body->posr.R,c); } void dJointSetPRAxis2 (dJointID j, dReal x, dReal y, dReal z) { dxJointPR* joint = (dxJointPR*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); setAxes (joint,x,y,z,joint->axisR1,joint->axisR2); PRComputeInitialRelativeRotation (joint); } void dJointSetPRParam (dJointID j, int parameter, dReal value) { dxJointPR* joint = (dxJointPR*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); if ((parameter & 0xff00) == 0x100) { joint->limotR.set (parameter,value); } else { joint->limotP.set (parameter & 0xff,value); } } void dJointGetPRAnchor (dJointID j, dVector3 result) { dxJointPR* joint = (dxJointPR*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); if (joint->node[1].body) getAnchor2 (joint,result,joint->anchor2); else { result[0] = joint->anchor2[0]; result[1] = joint->anchor2[1]; result[2] = joint->anchor2[2]; } } void dJointGetPRAxis1 (dJointID j, dVector3 result) { dxJointPR* joint = (dxJointPR*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); getAxis(joint, result, joint->axisP1); } void dJointGetPRAxis2 (dJointID j, dVector3 result) { dxJointPR* joint = (dxJointPR*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(result,"bad result argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); getAxis(joint, result, joint->axisR1); } dReal dJointGetPRParam (dJointID j, int parameter) { dxJointPR* joint = (dxJointPR*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not Prismatic and Rotoide"); if ((parameter & 0xff00) == 0x100) { return joint->limotR.get (parameter & 0xff); } else { return joint->limotP.get (parameter); } } void dJointAddPRTorque (dJointID j, dReal torque) { dxJointPR* joint = (dxJointPR*)j; dVector3 axis; dAASSERT(joint); dUASSERT(joint->vtable == &__dPR_vtable,"joint is not a Prismatic and Rotoide"); if (joint->flags & dJOINT_REVERSE) torque = -torque; getAxis (joint,axis,joint->axisR1); axis[0] *= torque; axis[1] *= torque; axis[2] *= torque; if (joint->node[0].body != 0) dBodyAddTorque (joint->node[0].body, axis[0], axis[1], axis[2]); if (joint->node[1].body != 0) dBodyAddTorque(joint->node[1].body, -axis[0], -axis[1], -axis[2]); } dxJoint::Vtable __dPR_vtable = { sizeof(dxJointPR), (dxJoint::init_fn*) PRInit, (dxJoint::getInfo1_fn*) PRGetInfo1, (dxJoint::getInfo2_fn*) PRGetInfo2, dJointTypePR }; //**************************************************************************** // angular motor static void amotorInit (dxJointAMotor *j) { int i; j->num = 0; j->mode = dAMotorUser; for (i=0; i<3; i++) { j->rel[i] = 0; dSetZero (j->axis[i],4); j->limot[i].init (j->world); j->angle[i] = 0; } dSetZero (j->reference1,4); dSetZero (j->reference2,4); } // compute the 3 axes in global coordinates static void amotorComputeGlobalAxes (dxJointAMotor *joint, dVector3 ax[3]) { if (joint->mode == dAMotorEuler) { // special handling for euler mode dMULTIPLY0_331 (ax[0],joint->node[0].body->posr.R,joint->axis[0]); if (joint->node[1].body) { dMULTIPLY0_331 (ax[2],joint->node[1].body->posr.R,joint->axis[2]); } else { ax[2][0] = joint->axis[2][0]; ax[2][1] = joint->axis[2][1]; ax[2][2] = joint->axis[2][2]; } dCROSS (ax[1],=,ax[2],ax[0]); dNormalize3 (ax[1]); } else { for (int i=0; i < joint->num; i++) { if (joint->rel[i] == 1) { // relative to b1 dMULTIPLY0_331 (ax[i],joint->node[0].body->posr.R,joint->axis[i]); } else if (joint->rel[i] == 2) { // relative to b2 if (joint->node[1].body) { // jds: don't assert, just ignore dMULTIPLY0_331 (ax[i],joint->node[1].body->posr.R,joint->axis[i]); } } else { // global - just copy it ax[i][0] = joint->axis[i][0]; ax[i][1] = joint->axis[i][1]; ax[i][2] = joint->axis[i][2]; } } } } static void amotorComputeEulerAngles (dxJointAMotor *joint, dVector3 ax[3]) { // assumptions: // global axes already calculated --> ax // axis[0] is relative to body 1 --> global ax[0] // axis[2] is relative to body 2 --> global ax[2] // ax[1] = ax[2] x ax[0] // original ax[0] and ax[2] are perpendicular // reference1 is perpendicular to ax[0] (in body 1 frame) // reference2 is perpendicular to ax[2] (in body 2 frame) // all ax[] and reference vectors are unit length // calculate references in global frame dVector3 ref1,ref2; dMULTIPLY0_331 (ref1,joint->node[0].body->posr.R,joint->reference1); if (joint->node[1].body) { dMULTIPLY0_331 (ref2,joint->node[1].body->posr.R,joint->reference2); } else { ref2[0] = joint->reference2[0]; ref2[1] = joint->reference2[1]; ref2[2] = joint->reference2[2]; } // get q perpendicular to both ax[0] and ref1, get first euler angle dVector3 q; dCROSS (q,=,ax[0],ref1); joint->angle[0] = -dAtan2 (dDOT(ax[2],q),dDOT(ax[2],ref1)); // get q perpendicular to both ax[0] and ax[1], get second euler angle dCROSS (q,=,ax[0],ax[1]); joint->angle[1] = -dAtan2 (dDOT(ax[2],ax[0]),dDOT(ax[2],q)); // get q perpendicular to both ax[1] and ax[2], get third euler angle dCROSS (q,=,ax[1],ax[2]); joint->angle[2] = -dAtan2 (dDOT(ref2,ax[1]), dDOT(ref2,q)); } // set the reference vectors as follows: // * reference1 = current axis[2] relative to body 1 // * reference2 = current axis[0] relative to body 2 // this assumes that: // * axis[0] is relative to body 1 // * axis[2] is relative to body 2 static void amotorSetEulerReferenceVectors (dxJointAMotor *j) { if (j->node[0].body && j->node[1].body) { dVector3 r; // axis[2] and axis[0] in global coordinates dMULTIPLY0_331 (r,j->node[1].body->posr.R,j->axis[2]); dMULTIPLY1_331 (j->reference1,j->node[0].body->posr.R,r); dMULTIPLY0_331 (r,j->node[0].body->posr.R,j->axis[0]); dMULTIPLY1_331 (j->reference2,j->node[1].body->posr.R,r); } else { // jds // else if (j->node[0].body) { // dMULTIPLY1_331 (j->reference1,j->node[0].body->posr.R,j->axis[2]); // dMULTIPLY0_331 (j->reference2,j->node[0].body->posr.R,j->axis[0]); // We want to handle angular motors attached to passive geoms dVector3 r; // axis[2] and axis[0] in global coordinates r[0] = j->axis[2][0]; r[1] = j->axis[2][1]; r[2] = j->axis[2][2]; r[3] = j->axis[2][3]; dMULTIPLY1_331 (j->reference1,j->node[0].body->posr.R,r); dMULTIPLY0_331 (r,j->node[0].body->posr.R,j->axis[0]); j->reference2[0] += r[0]; j->reference2[1] += r[1]; j->reference2[2] += r[2]; j->reference2[3] += r[3]; } } static void amotorGetInfo1 (dxJointAMotor *j, dxJoint::Info1 *info) { info->m = 0; info->nub = 0; // compute the axes and angles, if in euler mode if (j->mode == dAMotorEuler) { dVector3 ax[3]; amotorComputeGlobalAxes (j,ax); amotorComputeEulerAngles (j,ax); } // see if we're powered or at a joint limit for each axis for (int i=0; i < j->num; i++) { if (j->limot[i].testRotationalLimit (j->angle[i]) || j->limot[i].fmax > 0) { info->m++; } } } static void amotorGetInfo2 (dxJointAMotor *joint, dxJoint::Info2 *info) { int i; // compute the axes (if not global) dVector3 ax[3]; amotorComputeGlobalAxes (joint,ax); // in euler angle mode we do not actually constrain the angular velocity // along the axes axis[0] and axis[2] (although we do use axis[1]) : // // to get constrain w2-w1 along ...not // ------ --------------------- ------ // d(angle[0])/dt = 0 ax[1] x ax[2] ax[0] // d(angle[1])/dt = 0 ax[1] // d(angle[2])/dt = 0 ax[0] x ax[1] ax[2] // // constraining w2-w1 along an axis 'a' means that a'*(w2-w1)=0. // to prove the result for angle[0], write the expression for angle[0] from // GetInfo1 then take the derivative. to prove this for angle[2] it is // easier to take the euler rate expression for d(angle[2])/dt with respect // to the components of w and set that to 0. dVector3 *axptr[3]; axptr[0] = &ax[0]; axptr[1] = &ax[1]; axptr[2] = &ax[2]; dVector3 ax0_cross_ax1; dVector3 ax1_cross_ax2; if (joint->mode == dAMotorEuler) { dCROSS (ax0_cross_ax1,=,ax[0],ax[1]); axptr[2] = &ax0_cross_ax1; dCROSS (ax1_cross_ax2,=,ax[1],ax[2]); axptr[0] = &ax1_cross_ax2; } int row=0; for (i=0; i < joint->num; i++) { row += joint->limot[i].addLimot (joint,info,row,*(axptr[i]),1); } } void dJointSetAMotorNumAxes (dJointID j, int num) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint && num >= 0 && num <= 3); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); if (joint->mode == dAMotorEuler) { joint->num = 3; } else { if (num < 0) num = 0; if (num > 3) num = 3; joint->num = num; } } void dJointSetAMotorAxis (dJointID j, int anum, int rel, dReal x, dReal y, dReal z) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint && anum >= 0 && anum <= 2 && rel >= 0 && rel <= 2); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); dUASSERT(!(!joint->node[1].body && (joint->flags & dJOINT_REVERSE) && rel == 1),"no first body, can't set axis rel=1"); dUASSERT(!(!joint->node[1].body && !(joint->flags & dJOINT_REVERSE) && rel == 2),"no second body, can't set axis rel=2"); if (anum < 0) anum = 0; if (anum > 2) anum = 2; // adjust rel to match the internal body order if (!joint->node[1].body && rel==2) rel = 1; joint->rel[anum] = rel; // x,y,z is always in global coordinates regardless of rel, so we may have // to convert it to be relative to a body dVector3 r; r[0] = x; r[1] = y; r[2] = z; r[3] = 0; if (rel > 0) { if (rel==1) { dMULTIPLY1_331 (joint->axis[anum],joint->node[0].body->posr.R,r); } else { // don't assert; handle the case of attachment to a bodiless geom if (joint->node[1].body) { // jds dMULTIPLY1_331 (joint->axis[anum],joint->node[1].body->posr.R,r); } else { joint->axis[anum][0] = r[0]; joint->axis[anum][1] = r[1]; joint->axis[anum][2] = r[2]; joint->axis[anum][3] = r[3]; } } } else { joint->axis[anum][0] = r[0]; joint->axis[anum][1] = r[1]; joint->axis[anum][2] = r[2]; } dNormalize3 (joint->axis[anum]); if (joint->mode == dAMotorEuler) amotorSetEulerReferenceVectors (joint); } void dJointSetAMotorAngle (dJointID j, int anum, dReal angle) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint && anum >= 0 && anum < 3); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); if (joint->mode == dAMotorUser) { if (anum < 0) anum = 0; if (anum > 3) anum = 3; joint->angle[anum] = angle; } } void dJointSetAMotorParam (dJointID j, int parameter, dReal value) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); int anum = parameter >> 8; if (anum < 0) anum = 0; if (anum > 2) anum = 2; parameter &= 0xff; joint->limot[anum].set (parameter, value); } void dJointSetAMotorMode (dJointID j, int mode) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); joint->mode = mode; if (joint->mode == dAMotorEuler) { joint->num = 3; amotorSetEulerReferenceVectors (joint); } } int dJointGetAMotorNumAxes (dJointID j) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); return joint->num; } void dJointGetAMotorAxis (dJointID j, int anum, dVector3 result) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint && anum >= 0 && anum < 3); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); if (anum < 0) anum = 0; if (anum > 2) anum = 2; if (joint->rel[anum] > 0) { if (joint->rel[anum]==1) { dMULTIPLY0_331 (result,joint->node[0].body->posr.R,joint->axis[anum]); } else { if (joint->node[1].body) { // jds dMULTIPLY0_331 (result,joint->node[1].body->posr.R,joint->axis[anum]); } else { result[0] = joint->axis[anum][0]; result[1] = joint->axis[anum][1]; result[2] = joint->axis[anum][2]; result[3] = joint->axis[anum][3]; } } } else { result[0] = joint->axis[anum][0]; result[1] = joint->axis[anum][1]; result[2] = joint->axis[anum][2]; } } int dJointGetAMotorAxisRel (dJointID j, int anum) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint && anum >= 0 && anum < 3); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); if (anum < 0) anum = 0; if (anum > 2) anum = 2; return joint->rel[anum]; } dReal dJointGetAMotorAngle (dJointID j, int anum) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint && anum >= 0 && anum < 3); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); if (anum < 0) anum = 0; if (anum > 3) anum = 3; return joint->angle[anum]; } dReal dJointGetAMotorAngleRate (dJointID j, int anum) { dxJointAMotor* joint = (dxJointAMotor*)j; // @@@ dDebug (0,"not yet implemented"); return 0; } dReal dJointGetAMotorParam (dJointID j, int parameter) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); int anum = parameter >> 8; if (anum < 0) anum = 0; if (anum > 2) anum = 2; parameter &= 0xff; return joint->limot[anum].get (parameter); } int dJointGetAMotorMode (dJointID j) { dxJointAMotor* joint = (dxJointAMotor*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); return joint->mode; } void dJointAddAMotorTorques (dJointID j, dReal torque1, dReal torque2, dReal torque3) { dxJointAMotor* joint = (dxJointAMotor*)j; dVector3 axes[3]; dAASSERT(joint); dUASSERT(joint->vtable == &__damotor_vtable,"joint is not an amotor"); if (joint->num == 0) return; dUASSERT((joint->flags & dJOINT_REVERSE) == 0, "dJointAddAMotorTorques not yet implemented for reverse AMotor joints"); amotorComputeGlobalAxes (joint,axes); axes[0][0] *= torque1; axes[0][1] *= torque1; axes[0][2] *= torque1; if (joint->num >= 2) { axes[0][0] += axes[1][0] * torque2; axes[0][1] += axes[1][1] * torque2; axes[0][2] += axes[1][2] * torque2; if (joint->num >= 3) { axes[0][0] += axes[2][0] * torque3; axes[0][1] += axes[2][1] * torque3; axes[0][2] += axes[2][2] * torque3; } } if (joint->node[0].body != 0) dBodyAddTorque (joint->node[0].body,axes[0][0],axes[0][1],axes[0][2]); if (joint->node[1].body != 0) dBodyAddTorque(joint->node[1].body, -axes[0][0], -axes[0][1], -axes[0][2]); } dxJoint::Vtable __damotor_vtable = { sizeof(dxJointAMotor), (dxJoint::init_fn*) amotorInit, (dxJoint::getInfo1_fn*) amotorGetInfo1, (dxJoint::getInfo2_fn*) amotorGetInfo2, dJointTypeAMotor}; //**************************************************************************** // lmotor joint static void lmotorInit (dxJointLMotor *j) { int i; j->num = 0; for (i=0;i<3;i++) { dSetZero(j->axis[i],4); j->limot[i].init(j->world); } } static void lmotorComputeGlobalAxes (dxJointLMotor *joint, dVector3 ax[3]) { for (int i=0; i< joint->num; i++) { if (joint->rel[i] == 1) { dMULTIPLY0_331 (ax[i],joint->node[0].body->posr.R,joint->axis[i]); } else if (joint->rel[i] == 2) { if (joint->node[1].body) { // jds: don't assert, just ignore dMULTIPLY0_331 (ax[i],joint->node[1].body->posr.R,joint->axis[i]); } } else { ax[i][0] = joint->axis[i][0]; ax[i][1] = joint->axis[i][1]; ax[i][2] = joint->axis[i][2]; } } } static void lmotorGetInfo1 (dxJointLMotor *j, dxJoint::Info1 *info) { info->m = 0; info->nub = 0; for (int i=0; i < j->num; i++) { if (j->limot[i].fmax > 0) { info->m++; } } } static void lmotorGetInfo2 (dxJointLMotor *joint, dxJoint::Info2 *info) { int row=0; dVector3 ax[3]; lmotorComputeGlobalAxes(joint, ax); for (int i=0;inum;i++) { row += joint->limot[i].addLimot(joint,info,row,ax[i], 0); } } void dJointSetLMotorAxis (dJointID j, int anum, int rel, dReal x, dReal y, dReal z) { dxJointLMotor* joint = (dxJointLMotor*)j; //for now we are ignoring rel! dAASSERT(joint && anum >= 0 && anum <= 2 && rel >= 0 && rel <= 2); dUASSERT(joint->vtable == &__dlmotor_vtable,"joint is not an lmotor"); if (anum < 0) anum = 0; if (anum > 2) anum = 2; if (!joint->node[1].body && rel==2) rel = 1; //ref 1 joint->rel[anum] = rel; dVector3 r; r[0] = x; r[1] = y; r[2] = z; r[3] = 0; if (rel > 0) { if (rel==1) { dMULTIPLY1_331 (joint->axis[anum],joint->node[0].body->posr.R,r); } else { //second body has to exists thanks to ref 1 line dMULTIPLY1_331 (joint->axis[anum],joint->node[1].body->posr.R,r); } } else { joint->axis[anum][0] = r[0]; joint->axis[anum][1] = r[1]; joint->axis[anum][2] = r[2]; } dNormalize3 (joint->axis[anum]); } void dJointSetLMotorNumAxes (dJointID j, int num) { dxJointLMotor* joint = (dxJointLMotor*)j; dAASSERT(joint && num >= 0 && num <= 3); dUASSERT(joint->vtable == &__dlmotor_vtable,"joint is not an lmotor"); if (num < 0) num = 0; if (num > 3) num = 3; joint->num = num; } void dJointSetLMotorParam (dJointID j, int parameter, dReal value) { dxJointLMotor* joint = (dxJointLMotor*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__dlmotor_vtable,"joint is not an lmotor"); int anum = parameter >> 8; if (anum < 0) anum = 0; if (anum > 2) anum = 2; parameter &= 0xff; joint->limot[anum].set (parameter, value); } int dJointGetLMotorNumAxes (dJointID j) { dxJointLMotor* joint = (dxJointLMotor*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__dlmotor_vtable,"joint is not an lmotor"); return joint->num; } void dJointGetLMotorAxis (dJointID j, int anum, dVector3 result) { dxJointLMotor* joint = (dxJointLMotor*)j; dAASSERT(joint && anum >= 0 && anum < 3); dUASSERT(joint->vtable == &__dlmotor_vtable,"joint is not an lmotor"); if (anum < 0) anum = 0; if (anum > 2) anum = 2; result[0] = joint->axis[anum][0]; result[1] = joint->axis[anum][1]; result[2] = joint->axis[anum][2]; } dReal dJointGetLMotorParam (dJointID j, int parameter) { dxJointLMotor* joint = (dxJointLMotor*)j; dAASSERT(joint); dUASSERT(joint->vtable == &__dlmotor_vtable,"joint is not an lmotor"); int anum = parameter >> 8; if (anum < 0) anum = 0; if (anum > 2) anum = 2; parameter &= 0xff; return joint->limot[anum].get (parameter); } dxJoint::Vtable __dlmotor_vtable = { sizeof(dxJointLMotor), (dxJoint::init_fn*) lmotorInit, (dxJoint::getInfo1_fn*) lmotorGetInfo1, (dxJoint::getInfo2_fn*) lmotorGetInfo2, dJointTypeLMotor }; //**************************************************************************** // fixed joint static void fixedInit (dxJointFixed *j) { dSetZero (j->offset,4); dSetZero (j->qrel,4); } static void fixedGetInfo1 (dxJointFixed *j, dxJoint::Info1 *info) { info->m = 6; info->nub = 6; } static void fixedGetInfo2 (dxJointFixed *joint, dxJoint::Info2 *info) { int s = info->rowskip; // Three rows for orientation setFixedOrientation(joint, info, joint->qrel, 3); // Three rows for position. // set jacobian info->J1l[0] = 1; info->J1l[s+1] = 1; info->J1l[2*s+2] = 1; dVector3 ofs; dMULTIPLY0_331 (ofs,joint->node[0].body->posr.R,joint->offset); if (joint->node[1].body) { dCROSSMAT (info->J1a,ofs,s,+,-); info->J2l[0] = -1; info->J2l[s+1] = -1; info->J2l[2*s+2] = -1; } // set right hand side for the first three rows (linear) dReal k = info->fps * info->erp; if (joint->node[1].body) { for (int j=0; j<3; j++) info->c[j] = k * (joint->node[1].body->posr.pos[j] - joint->node[0].body->posr.pos[j] + ofs[j]); } else { for (int j=0; j<3; j++) info->c[j] = k * (joint->offset[j] - joint->node[0].body->posr.pos[j]); } } void dJointSetFixed (dJointID j) { dxJointFixed* joint = (dxJointFixed*)j; dUASSERT(joint,"bad joint argument"); dUASSERT(joint->vtable == &__dfixed_vtable,"joint is not fixed"); int i; // This code is taken from sJointSetSliderAxis(), we should really put the // common code in its own function. // compute the offset between the bodies if (joint->node[0].body) { if (joint->node[1].body) { dQMultiply1 (joint->qrel,joint->node[0].body->q,joint->node[1].body->q); dReal ofs[4]; for (i=0; i<4; i++) ofs[i] = joint->node[0].body->posr.pos[i]; for (i=0; i<4; i++) ofs[i] -= joint->node[1].body->posr.pos[i]; dMULTIPLY1_331 (joint->offset,joint->node[0].body->posr.R,ofs); } else { // set joint->qrel to the transpose of the first body's q joint->qrel[0] = joint->node[0].body->q[0]; for (i=1; i<4; i++) joint->qrel[i] = -joint->node[0].body->q[i]; for (i=0; i<4; i++) joint->offset[i] = joint->node[0].body->posr.pos[i]; } } } dxJoint::Vtable __dfixed_vtable = { sizeof(dxJointFixed), (dxJoint::init_fn*) fixedInit, (dxJoint::getInfo1_fn*) fixedGetInfo1, (dxJoint::getInfo2_fn*) fixedGetInfo2, dJointTypeFixed}; //**************************************************************************** // null joint static void nullGetInfo1 (dxJointNull *j, dxJoint::Info1 *info) { info->m = 0; info->nub = 0; } static void nullGetInfo2 (dxJointNull *joint, dxJoint::Info2 *info) { dDebug (0,"this should never get called"); } dxJoint::Vtable __dnull_vtable = { sizeof(dxJointNull), (dxJoint::init_fn*) 0, (dxJoint::getInfo1_fn*) nullGetInfo1, (dxJoint::getInfo2_fn*) nullGetInfo2, dJointTypeNull}; /* This code is part of the Plane2D ODE joint by psero@gmx.de Wed Apr 23 18:53:43 CEST 2003 Add this code to the file: ode/src/joint.cpp */ # define VoXYZ(v1, o1, x, y, z) \ ( \ (v1)[0] o1 (x), \ (v1)[1] o1 (y), \ (v1)[2] o1 (z) \ ) static dReal Midentity[3][3] = { { 1, 0, 0 }, { 0, 1, 0 }, { 0, 0, 1, } }; static void plane2dInit (dxJointPlane2D *j) /*********************************************/ { /* MINFO ("plane2dInit ()"); */ j->motor_x.init (j->world); j->motor_y.init (j->world); j->motor_angle.init (j->world); } static void plane2dGetInfo1 (dxJointPlane2D *j, dxJoint::Info1 *info) /***********************************************************************/ { /* MINFO ("plane2dGetInfo1 ()"); */ info->nub = 3; info->m = 3; if (j->motor_x.fmax > 0) j->row_motor_x = info->m ++; if (j->motor_y.fmax > 0) j->row_motor_y = info->m ++; if (j->motor_angle.fmax > 0) j->row_motor_angle = info->m ++; } static void plane2dGetInfo2 (dxJointPlane2D *joint, dxJoint::Info2 *info) /***************************************************************************/ { int r0 = 0, r1 = info->rowskip, r2 = 2 * r1; dReal eps = info->fps * info->erp; /* MINFO ("plane2dGetInfo2 ()"); */ /* v = v1, w = omega1 (v2, omega2 not important (== static environment)) constraint equations: xz = 0 wx = 0 wy = 0 <=> ( 0 0 1 ) (vx) ( 0 0 0 ) (wx) ( 0 ) ( 0 0 0 ) (vy) + ( 1 0 0 ) (wy) = ( 0 ) ( 0 0 0 ) (vz) ( 0 1 0 ) (wz) ( 0 ) J1/J1l Omega1/J1a */ // fill in linear and angular coeff. for left hand side: VoXYZ (&info->J1l[r0], =, 0, 0, 1); VoXYZ (&info->J1l[r1], =, 0, 0, 0); VoXYZ (&info->J1l[r2], =, 0, 0, 0); VoXYZ (&info->J1a[r0], =, 0, 0, 0); VoXYZ (&info->J1a[r1], =, 1, 0, 0); VoXYZ (&info->J1a[r2], =, 0, 1, 0); // error correction (against drift): // a) linear vz, so that z (== pos[2]) == 0 info->c[0] = eps * -joint->node[0].body->posr.pos[2]; # if 0 // b) angular correction? -> left to application !!! dReal *body_z_axis = &joint->node[0].body->R[8]; info->c[1] = eps * +atan2 (body_z_axis[1], body_z_axis[2]); // wx error info->c[2] = eps * -atan2 (body_z_axis[0], body_z_axis[2]); // wy error # endif // if the slider is powered, or has joint limits, add in the extra row: if (joint->row_motor_x > 0) joint->motor_x.addLimot ( joint, info, joint->row_motor_x, Midentity[0], 0); if (joint->row_motor_y > 0) joint->motor_y.addLimot ( joint, info, joint->row_motor_y, Midentity[1], 0); if (joint->row_motor_angle > 0) joint->motor_angle.addLimot ( joint, info, joint->row_motor_angle, Midentity[2], 1); } dxJoint::Vtable __dplane2d_vtable = { sizeof (dxJointPlane2D), (dxJoint::init_fn*) plane2dInit, (dxJoint::getInfo1_fn*) plane2dGetInfo1, (dxJoint::getInfo2_fn*) plane2dGetInfo2, dJointTypePlane2D }; void dJointSetPlane2DXParam (dxJoint *joint, int parameter, dReal value) { dUASSERT (joint, "bad joint argument"); dUASSERT (joint->vtable == &__dplane2d_vtable, "joint is not a plane2d"); dxJointPlane2D* joint2d = (dxJointPlane2D*)( joint ); joint2d->motor_x.set (parameter, value); } void dJointSetPlane2DYParam (dxJoint *joint, int parameter, dReal value) { dUASSERT (joint, "bad joint argument"); dUASSERT (joint->vtable == &__dplane2d_vtable, "joint is not a plane2d"); dxJointPlane2D* joint2d = (dxJointPlane2D*)( joint ); joint2d->motor_y.set (parameter, value); } void dJointSetPlane2DAngleParam (dxJoint *joint, int parameter, dReal value) { dUASSERT (joint, "bad joint argument"); dUASSERT (joint->vtable == &__dplane2d_vtable, "joint is not a plane2d"); dxJointPlane2D* joint2d = (dxJointPlane2D*)( joint ); joint2d->motor_angle.set (parameter, value); }