virtualx-engine/servers/physics/joints/generic_6dof_joint_sw.cpp
2017-04-08 00:11:42 +02:00

594 lines
18 KiB
C++

/*************************************************************************/
/* generic_6dof_joint_sw.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md) */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
/*
Adapted to Godot from the Bullet library.
See corresponding header file for licensing info.
*/
#include "generic_6dof_joint_sw.h"
#define GENERIC_D6_DISABLE_WARMSTARTING 1
//////////////////////////// G6DOFRotationalLimitMotorSW ////////////////////////////////////
int G6DOFRotationalLimitMotorSW::testLimitValue(real_t test_value) {
if (m_loLimit > m_hiLimit) {
m_currentLimit = 0; //Free from violation
return 0;
}
if (test_value < m_loLimit) {
m_currentLimit = 1; //low limit violation
m_currentLimitError = test_value - m_loLimit;
return 1;
} else if (test_value > m_hiLimit) {
m_currentLimit = 2; //High limit violation
m_currentLimitError = test_value - m_hiLimit;
return 2;
};
m_currentLimit = 0; //Free from violation
return 0;
}
real_t G6DOFRotationalLimitMotorSW::solveAngularLimits(
real_t timeStep, Vector3 &axis, real_t jacDiagABInv,
BodySW *body0, BodySW *body1) {
if (needApplyTorques() == false) return 0.0f;
real_t target_velocity = m_targetVelocity;
real_t maxMotorForce = m_maxMotorForce;
//current error correction
if (m_currentLimit != 0) {
target_velocity = -m_ERP * m_currentLimitError / (timeStep);
maxMotorForce = m_maxLimitForce;
}
maxMotorForce *= timeStep;
// current velocity difference
Vector3 vel_diff = body0->get_angular_velocity();
if (body1) {
vel_diff -= body1->get_angular_velocity();
}
real_t rel_vel = axis.dot(vel_diff);
// correction velocity
real_t motor_relvel = m_limitSoftness * (target_velocity - m_damping * rel_vel);
if (motor_relvel < CMP_EPSILON && motor_relvel > -CMP_EPSILON) {
return 0.0f; //no need for applying force
}
// correction impulse
real_t unclippedMotorImpulse = (1 + m_bounce) * motor_relvel * jacDiagABInv;
// clip correction impulse
real_t clippedMotorImpulse;
///@todo: should clip against accumulated impulse
if (unclippedMotorImpulse > 0.0f) {
clippedMotorImpulse = unclippedMotorImpulse > maxMotorForce ? maxMotorForce : unclippedMotorImpulse;
} else {
clippedMotorImpulse = unclippedMotorImpulse < -maxMotorForce ? -maxMotorForce : unclippedMotorImpulse;
}
// sort with accumulated impulses
real_t lo = real_t(-1e30);
real_t hi = real_t(1e30);
real_t oldaccumImpulse = m_accumulatedImpulse;
real_t sum = oldaccumImpulse + clippedMotorImpulse;
m_accumulatedImpulse = sum > hi ? real_t(0.) : sum < lo ? real_t(0.) : sum;
clippedMotorImpulse = m_accumulatedImpulse - oldaccumImpulse;
Vector3 motorImp = clippedMotorImpulse * axis;
body0->apply_torque_impulse(motorImp);
if (body1) body1->apply_torque_impulse(-motorImp);
return clippedMotorImpulse;
}
//////////////////////////// End G6DOFRotationalLimitMotorSW ////////////////////////////////////
//////////////////////////// G6DOFTranslationalLimitMotorSW ////////////////////////////////////
real_t G6DOFTranslationalLimitMotorSW::solveLinearAxis(
real_t timeStep,
real_t jacDiagABInv,
BodySW *body1, const Vector3 &pointInA,
BodySW *body2, const Vector3 &pointInB,
int limit_index,
const Vector3 &axis_normal_on_a,
const Vector3 &anchorPos) {
///find relative velocity
// Vector3 rel_pos1 = pointInA - body1->get_transform().origin;
// Vector3 rel_pos2 = pointInB - body2->get_transform().origin;
Vector3 rel_pos1 = anchorPos - body1->get_transform().origin;
Vector3 rel_pos2 = anchorPos - body2->get_transform().origin;
Vector3 vel1 = body1->get_velocity_in_local_point(rel_pos1);
Vector3 vel2 = body2->get_velocity_in_local_point(rel_pos2);
Vector3 vel = vel1 - vel2;
real_t rel_vel = axis_normal_on_a.dot(vel);
/// apply displacement correction
//positional error (zeroth order error)
real_t depth = -(pointInA - pointInB).dot(axis_normal_on_a);
real_t lo = real_t(-1e30);
real_t hi = real_t(1e30);
real_t minLimit = m_lowerLimit[limit_index];
real_t maxLimit = m_upperLimit[limit_index];
//handle the limits
if (minLimit < maxLimit) {
{
if (depth > maxLimit) {
depth -= maxLimit;
lo = real_t(0.);
} else {
if (depth < minLimit) {
depth -= minLimit;
hi = real_t(0.);
} else {
return 0.0f;
}
}
}
}
real_t normalImpulse = m_limitSoftness[limit_index] * (m_restitution[limit_index] * depth / timeStep - m_damping[limit_index] * rel_vel) * jacDiagABInv;
real_t oldNormalImpulse = m_accumulatedImpulse[limit_index];
real_t sum = oldNormalImpulse + normalImpulse;
m_accumulatedImpulse[limit_index] = sum > hi ? real_t(0.) : sum < lo ? real_t(0.) : sum;
normalImpulse = m_accumulatedImpulse[limit_index] - oldNormalImpulse;
Vector3 impulse_vector = axis_normal_on_a * normalImpulse;
body1->apply_impulse(rel_pos1, impulse_vector);
body2->apply_impulse(rel_pos2, -impulse_vector);
return normalImpulse;
}
//////////////////////////// G6DOFTranslationalLimitMotorSW ////////////////////////////////////
Generic6DOFJointSW::Generic6DOFJointSW(BodySW *rbA, BodySW *rbB, const Transform &frameInA, const Transform &frameInB, bool useLinearReferenceFrameA)
: JointSW(_arr, 2), m_frameInA(frameInA), m_frameInB(frameInB),
m_useLinearReferenceFrameA(useLinearReferenceFrameA) {
A = rbA;
B = rbB;
A->add_constraint(this, 0);
B->add_constraint(this, 1);
}
void Generic6DOFJointSW::calculateAngleInfo() {
Basis relative_frame = m_calculatedTransformA.basis.inverse() * m_calculatedTransformB.basis;
m_calculatedAxisAngleDiff = relative_frame.get_euler();
// 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.
Vector3 axis0 = m_calculatedTransformB.basis.get_axis(0);
Vector3 axis2 = m_calculatedTransformA.basis.get_axis(2);
m_calculatedAxis[1] = axis2.cross(axis0);
m_calculatedAxis[0] = m_calculatedAxis[1].cross(axis2);
m_calculatedAxis[2] = axis0.cross(m_calculatedAxis[1]);
/*
if(m_debugDrawer)
{
char buff[300];
sprintf(buff,"\n X: %.2f ; Y: %.2f ; Z: %.2f ",
m_calculatedAxisAngleDiff[0],
m_calculatedAxisAngleDiff[1],
m_calculatedAxisAngleDiff[2]);
m_debugDrawer->reportErrorWarning(buff);
}
*/
}
void Generic6DOFJointSW::calculateTransforms() {
m_calculatedTransformA = A->get_transform() * m_frameInA;
m_calculatedTransformB = B->get_transform() * m_frameInB;
calculateAngleInfo();
}
void Generic6DOFJointSW::buildLinearJacobian(
JacobianEntrySW &jacLinear, const Vector3 &normalWorld,
const Vector3 &pivotAInW, const Vector3 &pivotBInW) {
memnew_placement(&jacLinear, JacobianEntrySW(
A->get_principal_inertia_axes().transposed(),
B->get_principal_inertia_axes().transposed(),
pivotAInW - A->get_transform().origin - A->get_center_of_mass(),
pivotBInW - B->get_transform().origin - B->get_center_of_mass(),
normalWorld,
A->get_inv_inertia(),
A->get_inv_mass(),
B->get_inv_inertia(),
B->get_inv_mass()));
}
void Generic6DOFJointSW::buildAngularJacobian(
JacobianEntrySW &jacAngular, const Vector3 &jointAxisW) {
memnew_placement(&jacAngular, JacobianEntrySW(jointAxisW,
A->get_principal_inertia_axes().transposed(),
B->get_principal_inertia_axes().transposed(),
A->get_inv_inertia(),
B->get_inv_inertia()));
}
bool Generic6DOFJointSW::testAngularLimitMotor(int axis_index) {
real_t angle = m_calculatedAxisAngleDiff[axis_index];
//test limits
m_angularLimits[axis_index].testLimitValue(angle);
return m_angularLimits[axis_index].needApplyTorques();
}
bool Generic6DOFJointSW::setup(real_t p_step) {
// Clear accumulated impulses for the next simulation step
m_linearLimits.m_accumulatedImpulse = Vector3(real_t(0.), real_t(0.), real_t(0.));
int i;
for (i = 0; i < 3; i++) {
m_angularLimits[i].m_accumulatedImpulse = real_t(0.);
}
//calculates transform
calculateTransforms();
// const Vector3& pivotAInW = m_calculatedTransformA.origin;
// const Vector3& pivotBInW = m_calculatedTransformB.origin;
calcAnchorPos();
Vector3 pivotAInW = m_AnchorPos;
Vector3 pivotBInW = m_AnchorPos;
// not used here
// Vector3 rel_pos1 = pivotAInW - A->get_transform().origin;
// Vector3 rel_pos2 = pivotBInW - B->get_transform().origin;
Vector3 normalWorld;
//linear part
for (i = 0; i < 3; i++) {
if (m_linearLimits.enable_limit[i] && m_linearLimits.isLimited(i)) {
if (m_useLinearReferenceFrameA)
normalWorld = m_calculatedTransformA.basis.get_axis(i);
else
normalWorld = m_calculatedTransformB.basis.get_axis(i);
buildLinearJacobian(
m_jacLinear[i], normalWorld,
pivotAInW, pivotBInW);
}
}
// angular part
for (i = 0; i < 3; i++) {
//calculates error angle
if (m_angularLimits[i].m_enableLimit && testAngularLimitMotor(i)) {
normalWorld = this->getAxis(i);
// Create angular atom
buildAngularJacobian(m_jacAng[i], normalWorld);
}
}
return true;
}
void Generic6DOFJointSW::solve(real_t timeStep) {
m_timeStep = timeStep;
//calculateTransforms();
int i;
// linear
Vector3 pointInA = m_calculatedTransformA.origin;
Vector3 pointInB = m_calculatedTransformB.origin;
real_t jacDiagABInv;
Vector3 linear_axis;
for (i = 0; i < 3; i++) {
if (m_linearLimits.enable_limit[i] && m_linearLimits.isLimited(i)) {
jacDiagABInv = real_t(1.) / m_jacLinear[i].getDiagonal();
if (m_useLinearReferenceFrameA)
linear_axis = m_calculatedTransformA.basis.get_axis(i);
else
linear_axis = m_calculatedTransformB.basis.get_axis(i);
m_linearLimits.solveLinearAxis(
m_timeStep,
jacDiagABInv,
A, pointInA,
B, pointInB,
i, linear_axis, m_AnchorPos);
}
}
// angular
Vector3 angular_axis;
real_t angularJacDiagABInv;
for (i = 0; i < 3; i++) {
if (m_angularLimits[i].m_enableLimit && m_angularLimits[i].needApplyTorques()) {
// get axis
angular_axis = getAxis(i);
angularJacDiagABInv = real_t(1.) / m_jacAng[i].getDiagonal();
m_angularLimits[i].solveAngularLimits(m_timeStep, angular_axis, angularJacDiagABInv, A, B);
}
}
}
void Generic6DOFJointSW::updateRHS(real_t timeStep) {
(void)timeStep;
}
Vector3 Generic6DOFJointSW::getAxis(int axis_index) const {
return m_calculatedAxis[axis_index];
}
real_t Generic6DOFJointSW::getAngle(int axis_index) const {
return m_calculatedAxisAngleDiff[axis_index];
}
void Generic6DOFJointSW::calcAnchorPos(void) {
real_t imA = A->get_inv_mass();
real_t imB = B->get_inv_mass();
real_t weight;
if (imB == real_t(0.0)) {
weight = real_t(1.0);
} else {
weight = imA / (imA + imB);
}
const Vector3 &pA = m_calculatedTransformA.origin;
const Vector3 &pB = m_calculatedTransformB.origin;
m_AnchorPos = pA * weight + pB * (real_t(1.0) - weight);
return;
} // Generic6DOFJointSW::calcAnchorPos()
void Generic6DOFJointSW::set_param(Vector3::Axis p_axis, PhysicsServer::G6DOFJointAxisParam p_param, real_t p_value) {
ERR_FAIL_INDEX(p_axis, 3);
switch (p_param) {
case PhysicsServer::G6DOF_JOINT_LINEAR_LOWER_LIMIT: {
m_linearLimits.m_lowerLimit[p_axis] = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_LINEAR_UPPER_LIMIT: {
m_linearLimits.m_upperLimit[p_axis] = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_LINEAR_LIMIT_SOFTNESS: {
m_linearLimits.m_limitSoftness[p_axis] = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_LINEAR_RESTITUTION: {
m_linearLimits.m_restitution[p_axis] = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_LINEAR_DAMPING: {
m_linearLimits.m_damping[p_axis] = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_LOWER_LIMIT: {
m_angularLimits[p_axis].m_loLimit = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_UPPER_LIMIT: {
m_angularLimits[p_axis].m_hiLimit = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_LIMIT_SOFTNESS: {
m_angularLimits[p_axis].m_limitSoftness = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_DAMPING: {
m_angularLimits[p_axis].m_damping = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_RESTITUTION: {
m_angularLimits[p_axis].m_bounce = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_FORCE_LIMIT: {
m_angularLimits[p_axis].m_maxLimitForce = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_ERP: {
m_angularLimits[p_axis].m_ERP = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_MOTOR_TARGET_VELOCITY: {
m_angularLimits[p_axis].m_targetVelocity = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_MOTOR_FORCE_LIMIT: {
m_angularLimits[p_axis].m_maxLimitForce = p_value;
} break;
}
}
real_t Generic6DOFJointSW::get_param(Vector3::Axis p_axis, PhysicsServer::G6DOFJointAxisParam p_param) const {
ERR_FAIL_INDEX_V(p_axis, 3, 0);
switch (p_param) {
case PhysicsServer::G6DOF_JOINT_LINEAR_LOWER_LIMIT: {
return m_linearLimits.m_lowerLimit[p_axis];
} break;
case PhysicsServer::G6DOF_JOINT_LINEAR_UPPER_LIMIT: {
return m_linearLimits.m_upperLimit[p_axis];
} break;
case PhysicsServer::G6DOF_JOINT_LINEAR_LIMIT_SOFTNESS: {
return m_linearLimits.m_limitSoftness[p_axis];
} break;
case PhysicsServer::G6DOF_JOINT_LINEAR_RESTITUTION: {
return m_linearLimits.m_restitution[p_axis];
} break;
case PhysicsServer::G6DOF_JOINT_LINEAR_DAMPING: {
return m_linearLimits.m_damping[p_axis];
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_LOWER_LIMIT: {
return m_angularLimits[p_axis].m_loLimit;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_UPPER_LIMIT: {
return m_angularLimits[p_axis].m_hiLimit;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_LIMIT_SOFTNESS: {
return m_angularLimits[p_axis].m_limitSoftness;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_DAMPING: {
return m_angularLimits[p_axis].m_damping;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_RESTITUTION: {
return m_angularLimits[p_axis].m_bounce;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_FORCE_LIMIT: {
return m_angularLimits[p_axis].m_maxLimitForce;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_ERP: {
return m_angularLimits[p_axis].m_ERP;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_MOTOR_TARGET_VELOCITY: {
return m_angularLimits[p_axis].m_targetVelocity;
} break;
case PhysicsServer::G6DOF_JOINT_ANGULAR_MOTOR_FORCE_LIMIT: {
return m_angularLimits[p_axis].m_maxMotorForce;
} break;
}
return 0;
}
void Generic6DOFJointSW::set_flag(Vector3::Axis p_axis, PhysicsServer::G6DOFJointAxisFlag p_flag, bool p_value) {
ERR_FAIL_INDEX(p_axis, 3);
switch (p_flag) {
case PhysicsServer::G6DOF_JOINT_FLAG_ENABLE_LINEAR_LIMIT: {
m_linearLimits.enable_limit[p_axis] = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_FLAG_ENABLE_ANGULAR_LIMIT: {
m_angularLimits[p_axis].m_enableLimit = p_value;
} break;
case PhysicsServer::G6DOF_JOINT_FLAG_ENABLE_MOTOR: {
m_angularLimits[p_axis].m_enableMotor = p_value;
} break;
}
}
bool Generic6DOFJointSW::get_flag(Vector3::Axis p_axis, PhysicsServer::G6DOFJointAxisFlag p_flag) const {
ERR_FAIL_INDEX_V(p_axis, 3, 0);
switch (p_flag) {
case PhysicsServer::G6DOF_JOINT_FLAG_ENABLE_LINEAR_LIMIT: {
return m_linearLimits.enable_limit[p_axis];
} break;
case PhysicsServer::G6DOF_JOINT_FLAG_ENABLE_ANGULAR_LIMIT: {
return m_angularLimits[p_axis].m_enableLimit;
} break;
case PhysicsServer::G6DOF_JOINT_FLAG_ENABLE_MOTOR: {
return m_angularLimits[p_axis].m_enableMotor;
} break;
}
return 0;
}