472 lines
15 KiB
C++
472 lines
15 KiB
C++
/*************************************************************************/
|
|
/* hinge_joint_sw.cpp */
|
|
/*************************************************************************/
|
|
/* This file is part of: */
|
|
/* GODOT ENGINE */
|
|
/* http://www.godotengine.org */
|
|
/*************************************************************************/
|
|
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
|
|
/* */
|
|
/* 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 */
|
|
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
|
|
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
|
|
/* 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 "hinge_joint_sw.h"
|
|
|
|
static void plane_space(const Vector3& n, Vector3& p, Vector3& q) {
|
|
|
|
if (Math::abs(n.z) > 0.707106781186547524400844362) {
|
|
// choose p in y-z plane
|
|
real_t a = n[1]*n[1] + n[2]*n[2];
|
|
real_t k = 1.0/Math::sqrt(a);
|
|
p=Vector3(0,-n[2]*k,n[1]*k);
|
|
// set q = n x p
|
|
q=Vector3(a*k,-n[0]*p[2],n[0]*p[1]);
|
|
}
|
|
else {
|
|
// choose p in x-y plane
|
|
real_t a = n.x*n.x + n.y*n.y;
|
|
real_t k = 1.0/Math::sqrt(a);
|
|
p=Vector3(-n.y*k,n.x*k,0);
|
|
// set q = n x p
|
|
q=Vector3(-n.z*p.y,n.z*p.x,a*k);
|
|
}
|
|
}
|
|
|
|
HingeJointSW::HingeJointSW(BodySW* rbA,BodySW* rbB, const Transform& frameA, const Transform& frameB) : JointSW(_arr,2) {
|
|
|
|
A=rbA;
|
|
B=rbB;
|
|
|
|
m_rbAFrame=frameA;
|
|
m_rbBFrame=frameB;
|
|
// flip axis
|
|
m_rbBFrame.basis[0][2] *= real_t(-1.);
|
|
m_rbBFrame.basis[1][2] *= real_t(-1.);
|
|
m_rbBFrame.basis[2][2] *= real_t(-1.);
|
|
|
|
|
|
//start with free
|
|
m_lowerLimit = Math_PI;
|
|
m_upperLimit = -Math_PI;
|
|
|
|
|
|
m_useLimit = false;
|
|
m_biasFactor = 0.3f;
|
|
m_relaxationFactor = 1.0f;
|
|
m_limitSoftness = 0.9f;
|
|
m_solveLimit = false;
|
|
|
|
tau=0.3;
|
|
|
|
m_angularOnly=false;
|
|
m_enableAngularMotor=false;
|
|
|
|
A->add_constraint(this,0);
|
|
B->add_constraint(this,1);
|
|
|
|
}
|
|
|
|
HingeJointSW::HingeJointSW(BodySW* rbA,BodySW* rbB, const Vector3& pivotInA,const Vector3& pivotInB,
|
|
const Vector3& axisInA,const Vector3& axisInB) : JointSW(_arr,2) {
|
|
|
|
A=rbA;
|
|
B=rbB;
|
|
|
|
m_rbAFrame.origin = pivotInA;
|
|
|
|
// since no frame is given, assume this to be zero angle and just pick rb transform axis
|
|
Vector3 rbAxisA1 = rbA->get_transform().basis.get_axis(0);
|
|
|
|
Vector3 rbAxisA2;
|
|
real_t projection = axisInA.dot(rbAxisA1);
|
|
if (projection >= 1.0f - CMP_EPSILON) {
|
|
rbAxisA1 = -rbA->get_transform().basis.get_axis(2);
|
|
rbAxisA2 = rbA->get_transform().basis.get_axis(1);
|
|
} else if (projection <= -1.0f + CMP_EPSILON) {
|
|
rbAxisA1 = rbA->get_transform().basis.get_axis(2);
|
|
rbAxisA2 = rbA->get_transform().basis.get_axis(1);
|
|
} else {
|
|
rbAxisA2 = axisInA.cross(rbAxisA1);
|
|
rbAxisA1 = rbAxisA2.cross(axisInA);
|
|
}
|
|
|
|
m_rbAFrame.basis=Basis( rbAxisA1.x,rbAxisA2.x,axisInA.x,
|
|
rbAxisA1.y,rbAxisA2.y,axisInA.y,
|
|
rbAxisA1.z,rbAxisA2.z,axisInA.z );
|
|
|
|
Quat rotationArc = Quat(axisInA,axisInB);
|
|
Vector3 rbAxisB1 = rotationArc.xform(rbAxisA1);
|
|
Vector3 rbAxisB2 = axisInB.cross(rbAxisB1);
|
|
|
|
m_rbBFrame.origin = pivotInB;
|
|
m_rbBFrame.basis=Basis( rbAxisB1.x,rbAxisB2.x,-axisInB.x,
|
|
rbAxisB1.y,rbAxisB2.y,-axisInB.y,
|
|
rbAxisB1.z,rbAxisB2.z,-axisInB.z );
|
|
|
|
//start with free
|
|
m_lowerLimit = Math_PI;
|
|
m_upperLimit = -Math_PI;
|
|
|
|
|
|
m_useLimit = false;
|
|
m_biasFactor = 0.3f;
|
|
m_relaxationFactor = 1.0f;
|
|
m_limitSoftness = 0.9f;
|
|
m_solveLimit = false;
|
|
|
|
tau=0.3;
|
|
|
|
m_angularOnly=false;
|
|
m_enableAngularMotor=false;
|
|
|
|
A->add_constraint(this,0);
|
|
B->add_constraint(this,1);
|
|
|
|
}
|
|
|
|
|
|
|
|
bool HingeJointSW::setup(float p_step) {
|
|
|
|
m_appliedImpulse = real_t(0.);
|
|
|
|
if (!m_angularOnly)
|
|
{
|
|
Vector3 pivotAInW = A->get_transform().xform(m_rbAFrame.origin);
|
|
Vector3 pivotBInW = B->get_transform().xform(m_rbBFrame.origin);
|
|
Vector3 relPos = pivotBInW - pivotAInW;
|
|
|
|
Vector3 normal[3];
|
|
if (relPos.length_squared() > CMP_EPSILON)
|
|
{
|
|
normal[0] = relPos.normalized();
|
|
}
|
|
else
|
|
{
|
|
normal[0]=Vector3(real_t(1.0),0,0);
|
|
}
|
|
|
|
plane_space(normal[0], normal[1], normal[2]);
|
|
|
|
for (int i=0;i<3;i++)
|
|
{
|
|
memnew_placement(&m_jac[i], 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(),
|
|
normal[i],
|
|
A->get_inv_inertia(),
|
|
A->get_inv_mass(),
|
|
B->get_inv_inertia(),
|
|
B->get_inv_mass()) );
|
|
}
|
|
}
|
|
|
|
//calculate two perpendicular jointAxis, orthogonal to hingeAxis
|
|
//these two jointAxis require equal angular velocities for both bodies
|
|
|
|
//this is unused for now, it's a todo
|
|
Vector3 jointAxis0local;
|
|
Vector3 jointAxis1local;
|
|
|
|
plane_space(m_rbAFrame.basis.get_axis(2),jointAxis0local,jointAxis1local);
|
|
|
|
A->get_transform().basis.xform( m_rbAFrame.basis.get_axis(2) );
|
|
Vector3 jointAxis0 = A->get_transform().basis.xform( jointAxis0local );
|
|
Vector3 jointAxis1 = A->get_transform().basis.xform( jointAxis1local );
|
|
Vector3 hingeAxisWorld = A->get_transform().basis.xform( m_rbAFrame.basis.get_axis(2) );
|
|
|
|
memnew_placement(&m_jacAng[0], JacobianEntrySW(jointAxis0,
|
|
A->get_principal_inertia_axes().transposed(),
|
|
B->get_principal_inertia_axes().transposed(),
|
|
A->get_inv_inertia(),
|
|
B->get_inv_inertia()));
|
|
|
|
memnew_placement(&m_jacAng[1], JacobianEntrySW(jointAxis1,
|
|
A->get_principal_inertia_axes().transposed(),
|
|
B->get_principal_inertia_axes().transposed(),
|
|
A->get_inv_inertia(),
|
|
B->get_inv_inertia()));
|
|
|
|
memnew_placement(&m_jacAng[2], JacobianEntrySW(hingeAxisWorld,
|
|
A->get_principal_inertia_axes().transposed(),
|
|
B->get_principal_inertia_axes().transposed(),
|
|
A->get_inv_inertia(),
|
|
B->get_inv_inertia()));
|
|
|
|
|
|
// Compute limit information
|
|
real_t hingeAngle = get_hinge_angle();
|
|
|
|
//print_line("angle: "+rtos(hingeAngle));
|
|
//set bias, sign, clear accumulator
|
|
m_correction = real_t(0.);
|
|
m_limitSign = real_t(0.);
|
|
m_solveLimit = false;
|
|
m_accLimitImpulse = real_t(0.);
|
|
|
|
|
|
|
|
/*if (m_useLimit) {
|
|
print_line("low: "+rtos(m_lowerLimit));
|
|
print_line("hi: "+rtos(m_upperLimit));
|
|
}*/
|
|
|
|
//if (m_lowerLimit < m_upperLimit)
|
|
if (m_useLimit && m_lowerLimit <= m_upperLimit)
|
|
{
|
|
//if (hingeAngle <= m_lowerLimit*m_limitSoftness)
|
|
if (hingeAngle <= m_lowerLimit)
|
|
{
|
|
m_correction = (m_lowerLimit - hingeAngle);
|
|
m_limitSign = 1.0f;
|
|
m_solveLimit = true;
|
|
}
|
|
//else if (hingeAngle >= m_upperLimit*m_limitSoftness)
|
|
else if (hingeAngle >= m_upperLimit)
|
|
{
|
|
m_correction = m_upperLimit - hingeAngle;
|
|
m_limitSign = -1.0f;
|
|
m_solveLimit = true;
|
|
}
|
|
}
|
|
|
|
//Compute K = J*W*J' for hinge axis
|
|
Vector3 axisA = A->get_transform().basis.xform( m_rbAFrame.basis.get_axis(2) );
|
|
m_kHinge = 1.0f / (A->compute_angular_impulse_denominator(axisA) +
|
|
B->compute_angular_impulse_denominator(axisA));
|
|
|
|
return true;
|
|
}
|
|
|
|
void HingeJointSW::solve(float p_step) {
|
|
|
|
Vector3 pivotAInW = A->get_transform().xform(m_rbAFrame.origin);
|
|
Vector3 pivotBInW = B->get_transform().xform(m_rbBFrame.origin);
|
|
|
|
//real_t tau = real_t(0.3);
|
|
|
|
//linear part
|
|
if (!m_angularOnly)
|
|
{
|
|
Vector3 rel_pos1 = pivotAInW - A->get_transform().origin;
|
|
Vector3 rel_pos2 = pivotBInW - B->get_transform().origin;
|
|
|
|
Vector3 vel1 = A->get_velocity_in_local_point(rel_pos1);
|
|
Vector3 vel2 = B->get_velocity_in_local_point(rel_pos2);
|
|
Vector3 vel = vel1 - vel2;
|
|
|
|
for (int i=0;i<3;i++)
|
|
{
|
|
const Vector3& normal = m_jac[i].m_linearJointAxis;
|
|
real_t jacDiagABInv = real_t(1.) / m_jac[i].getDiagonal();
|
|
|
|
real_t rel_vel;
|
|
rel_vel = normal.dot(vel);
|
|
//positional error (zeroth order error)
|
|
real_t depth = -(pivotAInW - pivotBInW).dot(normal); //this is the error projected on the normal
|
|
real_t impulse = depth*tau/p_step * jacDiagABInv - rel_vel * jacDiagABInv;
|
|
m_appliedImpulse += impulse;
|
|
Vector3 impulse_vector = normal * impulse;
|
|
A->apply_impulse(pivotAInW - A->get_transform().origin,impulse_vector);
|
|
B->apply_impulse(pivotBInW - B->get_transform().origin,-impulse_vector);
|
|
}
|
|
}
|
|
|
|
|
|
{
|
|
///solve angular part
|
|
|
|
// get axes in world space
|
|
Vector3 axisA = A->get_transform().basis.xform( m_rbAFrame.basis.get_axis(2) );
|
|
Vector3 axisB = B->get_transform().basis.xform( m_rbBFrame.basis.get_axis(2) );
|
|
|
|
const Vector3& angVelA = A->get_angular_velocity();
|
|
const Vector3& angVelB = B->get_angular_velocity();
|
|
|
|
Vector3 angVelAroundHingeAxisA = axisA * axisA.dot(angVelA);
|
|
Vector3 angVelAroundHingeAxisB = axisB * axisB.dot(angVelB);
|
|
|
|
Vector3 angAorthog = angVelA - angVelAroundHingeAxisA;
|
|
Vector3 angBorthog = angVelB - angVelAroundHingeAxisB;
|
|
Vector3 velrelOrthog = angAorthog-angBorthog;
|
|
{
|
|
//solve orthogonal angular velocity correction
|
|
real_t relaxation = real_t(1.);
|
|
real_t len = velrelOrthog.length();
|
|
if (len > real_t(0.00001))
|
|
{
|
|
Vector3 normal = velrelOrthog.normalized();
|
|
real_t denom = A->compute_angular_impulse_denominator(normal) +
|
|
B->compute_angular_impulse_denominator(normal);
|
|
// scale for mass and relaxation
|
|
velrelOrthog *= (real_t(1.)/denom) * m_relaxationFactor;
|
|
}
|
|
|
|
//solve angular positional correction
|
|
Vector3 angularError = -axisA.cross(axisB) *(real_t(1.)/p_step);
|
|
real_t len2 = angularError.length();
|
|
if (len2>real_t(0.00001))
|
|
{
|
|
Vector3 normal2 = angularError.normalized();
|
|
real_t denom2 = A->compute_angular_impulse_denominator(normal2) +
|
|
B->compute_angular_impulse_denominator(normal2);
|
|
angularError *= (real_t(1.)/denom2) * relaxation;
|
|
}
|
|
|
|
A->apply_torque_impulse(-velrelOrthog+angularError);
|
|
B->apply_torque_impulse(velrelOrthog-angularError);
|
|
|
|
// solve limit
|
|
if (m_solveLimit)
|
|
{
|
|
real_t amplitude = ( (angVelB - angVelA).dot( axisA )*m_relaxationFactor + m_correction* (real_t(1.)/p_step)*m_biasFactor ) * m_limitSign;
|
|
|
|
real_t impulseMag = amplitude * m_kHinge;
|
|
|
|
// Clamp the accumulated impulse
|
|
real_t temp = m_accLimitImpulse;
|
|
m_accLimitImpulse = MAX(m_accLimitImpulse + impulseMag, real_t(0) );
|
|
impulseMag = m_accLimitImpulse - temp;
|
|
|
|
|
|
Vector3 impulse = axisA * impulseMag * m_limitSign;
|
|
A->apply_torque_impulse(impulse);
|
|
B->apply_torque_impulse(-impulse);
|
|
}
|
|
}
|
|
|
|
//apply motor
|
|
if (m_enableAngularMotor)
|
|
{
|
|
//todo: add limits too
|
|
Vector3 angularLimit(0,0,0);
|
|
|
|
Vector3 velrel = angVelAroundHingeAxisA - angVelAroundHingeAxisB;
|
|
real_t projRelVel = velrel.dot(axisA);
|
|
|
|
real_t desiredMotorVel = m_motorTargetVelocity;
|
|
real_t motor_relvel = desiredMotorVel - projRelVel;
|
|
|
|
real_t unclippedMotorImpulse = m_kHinge * motor_relvel;
|
|
//todo: should clip against accumulated impulse
|
|
real_t clippedMotorImpulse = unclippedMotorImpulse > m_maxMotorImpulse ? m_maxMotorImpulse : unclippedMotorImpulse;
|
|
clippedMotorImpulse = clippedMotorImpulse < -m_maxMotorImpulse ? -m_maxMotorImpulse : clippedMotorImpulse;
|
|
Vector3 motorImp = clippedMotorImpulse * axisA;
|
|
|
|
A->apply_torque_impulse(motorImp+angularLimit);
|
|
B->apply_torque_impulse(-motorImp-angularLimit);
|
|
|
|
}
|
|
}
|
|
|
|
}
|
|
/*
|
|
void HingeJointSW::updateRHS(real_t timeStep)
|
|
{
|
|
(void)timeStep;
|
|
|
|
}
|
|
*/
|
|
|
|
static _FORCE_INLINE_ real_t atan2fast(real_t y, real_t x)
|
|
{
|
|
real_t coeff_1 = Math_PI / 4.0f;
|
|
real_t coeff_2 = 3.0f * coeff_1;
|
|
real_t abs_y = Math::abs(y);
|
|
real_t angle;
|
|
if (x >= 0.0f) {
|
|
real_t r = (x - abs_y) / (x + abs_y);
|
|
angle = coeff_1 - coeff_1 * r;
|
|
} else {
|
|
real_t r = (x + abs_y) / (abs_y - x);
|
|
angle = coeff_2 - coeff_1 * r;
|
|
}
|
|
return (y < 0.0f) ? -angle : angle;
|
|
}
|
|
|
|
|
|
real_t HingeJointSW::get_hinge_angle() {
|
|
const Vector3 refAxis0 = A->get_transform().basis.xform( m_rbAFrame.basis.get_axis(0) );
|
|
const Vector3 refAxis1 = A->get_transform().basis.xform( m_rbAFrame.basis.get_axis(1) );
|
|
const Vector3 swingAxis = B->get_transform().basis.xform( m_rbBFrame.basis.get_axis(1) );
|
|
|
|
return atan2fast( swingAxis.dot(refAxis0), swingAxis.dot(refAxis1) );
|
|
}
|
|
|
|
|
|
void HingeJointSW::set_param(PhysicsServer::HingeJointParam p_param, float p_value) {
|
|
|
|
switch (p_param) {
|
|
|
|
case PhysicsServer::HINGE_JOINT_BIAS: tau=p_value; break;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_UPPER: m_upperLimit=p_value; break;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_LOWER: m_lowerLimit=p_value; break;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_BIAS: m_biasFactor=p_value; break;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_SOFTNESS: m_limitSoftness=p_value; break;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_RELAXATION: m_relaxationFactor=p_value; break;
|
|
case PhysicsServer::HINGE_JOINT_MOTOR_TARGET_VELOCITY: m_motorTargetVelocity=p_value; break;
|
|
case PhysicsServer::HINGE_JOINT_MOTOR_MAX_IMPULSE: m_maxMotorImpulse=p_value; break;
|
|
|
|
}
|
|
}
|
|
|
|
float HingeJointSW::get_param(PhysicsServer::HingeJointParam p_param) const{
|
|
|
|
switch (p_param) {
|
|
|
|
case PhysicsServer::HINGE_JOINT_BIAS: return tau;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_UPPER: return m_upperLimit;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_LOWER: return m_lowerLimit;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_BIAS: return m_biasFactor;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_SOFTNESS: return m_limitSoftness;
|
|
case PhysicsServer::HINGE_JOINT_LIMIT_RELAXATION: return m_relaxationFactor;
|
|
case PhysicsServer::HINGE_JOINT_MOTOR_TARGET_VELOCITY: return m_motorTargetVelocity;
|
|
case PhysicsServer::HINGE_JOINT_MOTOR_MAX_IMPULSE: return m_maxMotorImpulse;
|
|
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void HingeJointSW::set_flag(PhysicsServer::HingeJointFlag p_flag, bool p_value){
|
|
|
|
switch (p_flag) {
|
|
case PhysicsServer::HINGE_JOINT_FLAG_USE_LIMIT: m_useLimit=p_value; break;
|
|
case PhysicsServer::HINGE_JOINT_FLAG_ENABLE_MOTOR: m_enableAngularMotor=p_value; break;
|
|
}
|
|
|
|
}
|
|
bool HingeJointSW::get_flag(PhysicsServer::HingeJointFlag p_flag) const{
|
|
|
|
switch (p_flag) {
|
|
case PhysicsServer::HINGE_JOINT_FLAG_USE_LIMIT: return m_useLimit;
|
|
case PhysicsServer::HINGE_JOINT_FLAG_ENABLE_MOTOR:return m_enableAngularMotor;
|
|
}
|
|
|
|
return false;
|
|
}
|