godot/scene/3d/vehicle_body.cpp
Rémi Verschelde d8223ffa75 Welcome in 2017, dear changelog reader!
That year should bring the long-awaited OpenGL ES 3.0 compatible renderer
with state-of-the-art rendering techniques tuned to work as low as middle
end handheld devices - without compromising with the possibilities given
for higher end desktop games of course. Great times ahead for the Godot
community and the gamers that will play our games!

(cherry picked from commit c7bc44d5ad)
2017-01-12 19:15:30 +01:00

1074 lines
31 KiB
C++

/*************************************************************************/
/* vehicle_body.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. */
/*************************************************************************/
#include "vehicle_body.h"
#define ROLLING_INFLUENCE_FIX
class btVehicleJacobianEntry
{
public:
Vector3 m_linearJointAxis;
Vector3 m_aJ;
Vector3 m_bJ;
Vector3 m_0MinvJt;
Vector3 m_1MinvJt;
//Optimization: can be stored in the w/last component of one of the vectors
real_t m_Adiag;
real_t getDiagonal() const { return m_Adiag; }
btVehicleJacobianEntry() {};
//constraint between two different rigidbodies
btVehicleJacobianEntry(
const Matrix3& world2A,
const Matrix3& world2B,
const Vector3& rel_pos1,
const Vector3& rel_pos2,
const Vector3& jointAxis,
const Vector3& inertiaInvA,
const real_t massInvA,
const Vector3& inertiaInvB,
const real_t massInvB)
:m_linearJointAxis(jointAxis)
{
m_aJ = world2A.xform(rel_pos1.cross(m_linearJointAxis));
m_bJ = world2B.xform(rel_pos2.cross(-m_linearJointAxis));
m_0MinvJt = inertiaInvA * m_aJ;
m_1MinvJt = inertiaInvB * m_bJ;
m_Adiag = massInvA + m_0MinvJt.dot(m_aJ) + massInvB + m_1MinvJt.dot(m_bJ);
//btAssert(m_Adiag > real_t(0.0));
}
real_t getRelativeVelocity(const Vector3& linvelA,const Vector3& angvelA,const Vector3& linvelB,const Vector3& angvelB)
{
Vector3 linrel = linvelA - linvelB;
Vector3 angvela = angvelA * m_aJ;
Vector3 angvelb = angvelB * m_bJ;
linrel *= m_linearJointAxis;
angvela += angvelb;
angvela += linrel;
real_t rel_vel2 = angvela[0]+angvela[1]+angvela[2];
return rel_vel2 + CMP_EPSILON;
}
};
void VehicleWheel::_notification(int p_what) {
if (p_what==NOTIFICATION_ENTER_TREE) {
if (!get_parent())
return;
VehicleBody *cb = get_parent()->cast_to<VehicleBody>();
if (!cb)
return;
body=cb;
local_xform=get_transform();
cb->wheels.push_back(this);
m_chassisConnectionPointCS = get_transform().origin;
m_wheelDirectionCS = -get_transform().basis.get_axis(Vector3::AXIS_Y).normalized();
m_wheelAxleCS = get_transform().basis.get_axis(Vector3::AXIS_X).normalized();
}
if (p_what==NOTIFICATION_EXIT_TREE) {
if (!get_parent())
return;
VehicleBody *cb = get_parent()->cast_to<VehicleBody>();
if (!cb)
return;
cb->wheels.erase(this);
body=NULL;
}
}
void VehicleWheel::_update(PhysicsDirectBodyState *s) {
if (m_raycastInfo.m_isInContact)
{
real_t project= m_raycastInfo.m_contactNormalWS.dot( m_raycastInfo.m_wheelDirectionWS );
Vector3 chassis_velocity_at_contactPoint;
Vector3 relpos = m_raycastInfo.m_contactPointWS - s->get_transform().origin;
chassis_velocity_at_contactPoint = s->get_linear_velocity() +
(s->get_angular_velocity()).cross(relpos);// * mPos);
real_t projVel = m_raycastInfo.m_contactNormalWS.dot( chassis_velocity_at_contactPoint );
if ( project >= real_t(-0.1))
{
m_suspensionRelativeVelocity = real_t(0.0);
m_clippedInvContactDotSuspension = real_t(1.0) / real_t(0.1);
}
else
{
real_t inv = real_t(-1.) / project;
m_suspensionRelativeVelocity = projVel * inv;
m_clippedInvContactDotSuspension = inv;
}
}
else // Not in contact : position wheel in a nice (rest length) position
{
m_raycastInfo.m_suspensionLength = m_suspensionRestLength;
m_suspensionRelativeVelocity = real_t(0.0);
m_raycastInfo.m_contactNormalWS = -m_raycastInfo.m_wheelDirectionWS;
m_clippedInvContactDotSuspension = real_t(1.0);
}
}
void VehicleWheel::set_radius(float p_radius) {
m_wheelRadius=p_radius;
update_gizmo();
}
float VehicleWheel::get_radius() const{
return m_wheelRadius;
}
void VehicleWheel::set_suspension_rest_length(float p_length){
m_suspensionRestLength=p_length;
update_gizmo();
}
float VehicleWheel::get_suspension_rest_length() const{
return m_suspensionRestLength;
}
void VehicleWheel::set_suspension_travel(float p_length){
m_maxSuspensionTravelCm=p_length/0.01;
}
float VehicleWheel::get_suspension_travel() const{
return m_maxSuspensionTravelCm*0.01;
}
void VehicleWheel::set_suspension_stiffness(float p_value){
m_suspensionStiffness=p_value;
}
float VehicleWheel::get_suspension_stiffness() const{
return m_suspensionStiffness;
}
void VehicleWheel::set_suspension_max_force(float p_value){
m_maxSuspensionForce=p_value;
}
float VehicleWheel::get_suspension_max_force() const{
return m_maxSuspensionForce;
}
void VehicleWheel::set_damping_compression(float p_value){
m_wheelsDampingCompression=p_value;
}
float VehicleWheel::get_damping_compression() const{
return m_wheelsDampingCompression;
}
void VehicleWheel::set_damping_relaxation(float p_value){
m_wheelsDampingRelaxation=p_value;
}
float VehicleWheel::get_damping_relaxation() const{
return m_wheelsDampingRelaxation;
}
void VehicleWheel::set_friction_slip(float p_value) {
m_frictionSlip=p_value;
}
float VehicleWheel::get_friction_slip() const{
return m_frictionSlip;
}
void VehicleWheel::_bind_methods() {
ObjectTypeDB::bind_method(_MD("set_radius","length"),&VehicleWheel::set_radius);
ObjectTypeDB::bind_method(_MD("get_radius"),&VehicleWheel::get_radius);
ObjectTypeDB::bind_method(_MD("set_suspension_rest_length","length"),&VehicleWheel::set_suspension_rest_length);
ObjectTypeDB::bind_method(_MD("get_suspension_rest_length"),&VehicleWheel::get_suspension_rest_length);
ObjectTypeDB::bind_method(_MD("set_suspension_travel","length"),&VehicleWheel::set_suspension_travel);
ObjectTypeDB::bind_method(_MD("get_suspension_travel"),&VehicleWheel::get_suspension_travel);
ObjectTypeDB::bind_method(_MD("set_suspension_stiffness","length"),&VehicleWheel::set_suspension_stiffness);
ObjectTypeDB::bind_method(_MD("get_suspension_stiffness"),&VehicleWheel::get_suspension_stiffness);
ObjectTypeDB::bind_method(_MD("set_suspension_max_force","length"),&VehicleWheel::set_suspension_max_force);
ObjectTypeDB::bind_method(_MD("get_suspension_max_force"),&VehicleWheel::get_suspension_max_force);
ObjectTypeDB::bind_method(_MD("set_damping_compression","length"),&VehicleWheel::set_damping_compression);
ObjectTypeDB::bind_method(_MD("get_damping_compression"),&VehicleWheel::get_damping_compression);
ObjectTypeDB::bind_method(_MD("set_damping_relaxation","length"),&VehicleWheel::set_damping_relaxation);
ObjectTypeDB::bind_method(_MD("get_damping_relaxation"),&VehicleWheel::get_damping_relaxation);
ObjectTypeDB::bind_method(_MD("set_use_as_traction","enable"),&VehicleWheel::set_use_as_traction);
ObjectTypeDB::bind_method(_MD("is_used_as_traction"),&VehicleWheel::is_used_as_traction);
ObjectTypeDB::bind_method(_MD("set_use_as_steering","enable"),&VehicleWheel::set_use_as_steering);
ObjectTypeDB::bind_method(_MD("is_used_as_steering"),&VehicleWheel::is_used_as_steering);
ObjectTypeDB::bind_method(_MD("set_friction_slip","length"),&VehicleWheel::set_friction_slip);
ObjectTypeDB::bind_method(_MD("get_friction_slip"),&VehicleWheel::get_friction_slip);
ADD_PROPERTY(PropertyInfo(Variant::BOOL,"type/traction"),_SCS("set_use_as_traction"),_SCS("is_used_as_traction"));
ADD_PROPERTY(PropertyInfo(Variant::BOOL,"type/steering"),_SCS("set_use_as_steering"),_SCS("is_used_as_steering"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"wheel/radius"),_SCS("set_radius"),_SCS("get_radius"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"wheel/rest_length"),_SCS("set_suspension_rest_length"),_SCS("get_suspension_rest_length"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"wheel/friction_slip"),_SCS("set_friction_slip"),_SCS("get_friction_slip"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"suspension/travel"),_SCS("set_suspension_travel"),_SCS("get_suspension_travel"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"suspension/stiffness"),_SCS("set_suspension_stiffness"),_SCS("get_suspension_stiffness"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"suspension/max_force"),_SCS("set_suspension_max_force"),_SCS("get_suspension_max_force"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"damping/compression"),_SCS("set_damping_compression"),_SCS("get_damping_compression"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"damping/relaxation"),_SCS("set_damping_relaxation"),_SCS("get_damping_relaxation"));
}
void VehicleWheel::set_use_as_traction(bool p_enable) {
engine_traction=p_enable;
}
bool VehicleWheel::is_used_as_traction() const{
return engine_traction;
}
void VehicleWheel::set_use_as_steering(bool p_enabled){
steers=p_enabled;
}
bool VehicleWheel::is_used_as_steering() const{
return steers;
}
VehicleWheel::VehicleWheel() {
steers=false;
engine_traction=false;
m_steering = real_t(0.);
//m_engineForce = real_t(0.);
m_rotation = real_t(0.);
m_deltaRotation = real_t(0.);
m_brake = real_t(0.);
m_rollInfluence = real_t(0.1);
m_suspensionRestLength = 0.15;
m_wheelRadius = 0.5;//0.28;
m_suspensionStiffness = 5.88;
m_wheelsDampingCompression = 0.83;
m_wheelsDampingRelaxation = 0.88;
m_frictionSlip = 10.5;
m_bIsFrontWheel = false;
m_maxSuspensionTravelCm = 500;
m_maxSuspensionForce = 6000;
m_suspensionRelativeVelocity=0;
m_clippedInvContactDotSuspension=1.0;
m_raycastInfo.m_isInContact=false;
body=NULL;
}
void VehicleBody::_update_wheel_transform(VehicleWheel& wheel ,PhysicsDirectBodyState *s) {
wheel.m_raycastInfo.m_isInContact = false;
Transform chassisTrans = s->get_transform();
//if (interpolatedTransform && (getRigidBody()->getMotionState()))
//{
// getRigidBody()->getMotionState()->getWorldTransform(chassisTrans);
//}
wheel.m_raycastInfo.m_hardPointWS = chassisTrans.xform( wheel.m_chassisConnectionPointCS );
//wheel.m_raycastInfo.m_hardPointWS+=s->get_linear_velocity()*s->get_step();
wheel.m_raycastInfo.m_wheelDirectionWS = chassisTrans.get_basis().xform( wheel.m_wheelDirectionCS).normalized();
wheel.m_raycastInfo.m_wheelAxleWS = chassisTrans.get_basis().xform( wheel.m_wheelAxleCS ).normalized();
}
void VehicleBody::_update_wheel(int p_idx,PhysicsDirectBodyState *s) {
VehicleWheel& wheel = *wheels[p_idx];
_update_wheel_transform(wheel,s);
Vector3 up = -wheel.m_raycastInfo.m_wheelDirectionWS;
const Vector3& right = wheel.m_raycastInfo.m_wheelAxleWS;
Vector3 fwd = up.cross(right);
fwd = fwd.normalized();
// up = right.cross(fwd);
// up.normalize();
//rotate around steering over de wheelAxleWS
real_t steering = wheel.steers?m_steeringValue:0.0;
//print_line(itos(p_idx)+": "+rtos(steering));
Matrix3 steeringMat(up,steering);
Matrix3 rotatingMat(right,-wheel.m_rotation);
// if (p_idx==1)
// print_line("steeringMat " +steeringMat);
Matrix3 basis2(
right[0],up[0],fwd[0],
right[1],up[1],fwd[1],
right[2],up[2],fwd[2]
);
wheel.m_worldTransform.set_basis(steeringMat * rotatingMat * basis2);
//wheel.m_worldTransform.set_basis(basis2 * (steeringMat * rotatingMat));
wheel.m_worldTransform.set_origin(
wheel.m_raycastInfo.m_hardPointWS + wheel.m_raycastInfo.m_wheelDirectionWS * wheel.m_raycastInfo.m_suspensionLength
);
}
real_t VehicleBody::_ray_cast(int p_idx,PhysicsDirectBodyState *s) {
VehicleWheel& wheel = *wheels[p_idx];
_update_wheel_transform(wheel,s);
real_t depth = -1;
real_t raylen = wheel.m_suspensionRestLength+wheel.m_wheelRadius;
Vector3 rayvector = wheel.m_raycastInfo.m_wheelDirectionWS * (raylen);
Vector3 source = wheel.m_raycastInfo.m_hardPointWS;
wheel.m_raycastInfo.m_contactPointWS = source + rayvector;
const Vector3& target = wheel.m_raycastInfo.m_contactPointWS;
source-=wheel.m_wheelRadius * wheel.m_raycastInfo.m_wheelDirectionWS;
real_t param = real_t(0.);
PhysicsDirectSpaceState::RayResult rr;
PhysicsDirectSpaceState *ss=s->get_space_state();
bool col = ss->intersect_ray(source,target,rr,exclude);
wheel.m_raycastInfo.m_groundObject = 0;
if (col)
{
//print_line("WHEEL "+itos(p_idx)+" FROM "+source+" TO: "+target);
//print_line("WHEEL "+itos(p_idx)+" COLLIDE? "+itos(col));
param = source.distance_to(rr.position)/source.distance_to(target);
depth = raylen * param;
wheel.m_raycastInfo.m_contactNormalWS = rr.normal;
wheel.m_raycastInfo.m_isInContact = true;
if (rr.collider)
wheel.m_raycastInfo.m_groundObject=rr.collider->cast_to<PhysicsBody>();
real_t hitDistance = param*raylen;
wheel.m_raycastInfo.m_suspensionLength = hitDistance - wheel.m_wheelRadius;
//clamp on max suspension travel
real_t minSuspensionLength = wheel.m_suspensionRestLength - wheel.m_maxSuspensionTravelCm*real_t(0.01);
real_t maxSuspensionLength = wheel.m_suspensionRestLength+ wheel.m_maxSuspensionTravelCm*real_t(0.01);
if (wheel.m_raycastInfo.m_suspensionLength < minSuspensionLength)
{
wheel.m_raycastInfo.m_suspensionLength = minSuspensionLength;
}
if (wheel.m_raycastInfo.m_suspensionLength > maxSuspensionLength)
{
wheel.m_raycastInfo.m_suspensionLength = maxSuspensionLength;
}
wheel.m_raycastInfo.m_contactPointWS = rr.position;
real_t denominator= wheel.m_raycastInfo.m_contactNormalWS.dot( wheel.m_raycastInfo.m_wheelDirectionWS );
Vector3 chassis_velocity_at_contactPoint;
//Vector3 relpos = wheel.m_raycastInfo.m_contactPointWS-getRigidBody()->getCenterOfMassPosition();
//chassis_velocity_at_contactPoint = getRigidBody()->getVelocityInLocalPoint(relpos);
chassis_velocity_at_contactPoint = s->get_linear_velocity() +
(s->get_angular_velocity()).cross(wheel.m_raycastInfo.m_contactPointWS-s->get_transform().origin);// * mPos);
real_t projVel = wheel.m_raycastInfo.m_contactNormalWS.dot( chassis_velocity_at_contactPoint );
if ( denominator >= real_t(-0.1))
{
wheel.m_suspensionRelativeVelocity = real_t(0.0);
wheel.m_clippedInvContactDotSuspension = real_t(1.0) / real_t(0.1);
}
else
{
real_t inv = real_t(-1.) / denominator;
wheel.m_suspensionRelativeVelocity = projVel * inv;
wheel.m_clippedInvContactDotSuspension = inv;
}
} else
{
wheel.m_raycastInfo.m_isInContact = false;
//put wheel info as in rest position
wheel.m_raycastInfo.m_suspensionLength = wheel.m_suspensionRestLength;
wheel.m_suspensionRelativeVelocity = real_t(0.0);
wheel.m_raycastInfo.m_contactNormalWS = - wheel.m_raycastInfo.m_wheelDirectionWS;
wheel.m_clippedInvContactDotSuspension = real_t(1.0);
}
return depth;
}
void VehicleBody::_update_suspension(PhysicsDirectBodyState *s)
{
real_t chassisMass = mass;
for (int w_it=0; w_it<wheels.size(); w_it++)
{
VehicleWheel& wheel_info = *wheels[w_it];
if ( wheel_info.m_raycastInfo.m_isInContact )
{
real_t force;
// Spring
{
real_t susp_length = wheel_info.m_suspensionRestLength;
real_t current_length = wheel_info.m_raycastInfo.m_suspensionLength;
real_t length_diff = (susp_length - current_length);
force = wheel_info.m_suspensionStiffness
* length_diff * wheel_info.m_clippedInvContactDotSuspension;
}
// Damper
{
real_t projected_rel_vel = wheel_info.m_suspensionRelativeVelocity;
{
real_t susp_damping;
if ( projected_rel_vel < real_t(0.0) )
{
susp_damping = wheel_info.m_wheelsDampingCompression;
}
else
{
susp_damping = wheel_info.m_wheelsDampingRelaxation;
}
force -= susp_damping * projected_rel_vel;
}
}
// RESULT
wheel_info.m_wheelsSuspensionForce = force * chassisMass;
if (wheel_info.m_wheelsSuspensionForce < real_t(0.))
{
wheel_info.m_wheelsSuspensionForce = real_t(0.);
}
}
else
{
wheel_info.m_wheelsSuspensionForce = real_t(0.0);
}
}
}
//bilateral constraint between two dynamic objects
void VehicleBody::_resolve_single_bilateral(PhysicsDirectBodyState *s, const Vector3& pos1,
PhysicsBody* body2, const Vector3& pos2, const Vector3& normal,real_t& impulse)
{
real_t normalLenSqr = normal.length_squared();
//ERR_FAIL_COND( normalLenSqr < real_t(1.1));
if (normalLenSqr > real_t(1.1))
{
impulse = real_t(0.);
return;
}
Vector3 rel_pos1 = pos1 - s->get_transform().origin;
Vector3 rel_pos2;
if (body2)
rel_pos2 = pos2 - body2->get_global_transform().origin;
//this jacobian entry could be re-used for all iterations
Vector3 vel1 = s->get_linear_velocity() + (s->get_angular_velocity()).cross(rel_pos1);// * mPos);
Vector3 vel2;
if (body2)
vel2=body2->get_linear_velocity() + body2->get_angular_velocity().cross(rel_pos2);
Vector3 vel = vel1 - vel2;
Matrix3 b2trans;
float b2invmass=0;
Vector3 b2lv;
Vector3 b2av;
Vector3 b2invinertia; //todo
if (body2) {
b2trans = body2->get_global_transform().basis.transposed();
b2invmass = body2->get_inverse_mass();
b2lv = body2->get_linear_velocity();
b2av = body2->get_angular_velocity();
}
btVehicleJacobianEntry jac(s->get_transform().basis.transposed(),
b2trans,
rel_pos1,
rel_pos2,
normal,
s->get_inverse_inertia(),
1.0/mass,
b2invinertia,
b2invmass);
real_t rel_vel = jac.getRelativeVelocity(
s->get_linear_velocity(),
s->get_transform().basis.transposed().xform(s->get_angular_velocity()),
b2lv,
b2trans.xform(b2av));
rel_vel = normal.dot(vel);
//TODO: move this into proper structure
real_t contactDamping = real_t(0.4);
#define ONLY_USE_LINEAR_MASS
#ifdef ONLY_USE_LINEAR_MASS
real_t massTerm = real_t(1.) / ((1.0/mass) + b2invmass);
impulse = - contactDamping * rel_vel * massTerm;
#else
real_t velocityImpulse = -contactDamping * rel_vel * jacDiagABInv;
impulse = velocityImpulse;
#endif
}
VehicleBody::btVehicleWheelContactPoint::btVehicleWheelContactPoint(PhysicsDirectBodyState *s,PhysicsBody* body1,const Vector3& frictionPosWorld,const Vector3& frictionDirectionWorld, real_t maxImpulse)
:m_s(s),
m_body1(body1),
m_frictionPositionWorld(frictionPosWorld),
m_frictionDirectionWorld(frictionDirectionWorld),
m_maxImpulse(maxImpulse)
{
float denom0=0;
float denom1=0;
{
Vector3 r0 = frictionPosWorld - s->get_transform().origin;
Vector3 c0 = (r0).cross(frictionDirectionWorld);
Vector3 vec = s->get_inverse_inertia_tensor().xform_inv(c0).cross(r0);
denom0= s->get_inverse_mass() + frictionDirectionWorld.dot(vec);
}
/* TODO: Why is this code unused?
if (body1) {
Vector3 r0 = frictionPosWorld - body1->get_global_transform().origin;
Vector3 c0 = (r0).cross(frictionDirectionWorld);
Vector3 vec = s->get_inverse_inertia_tensor().xform_inv(c0).cross(r0);
//denom1= body1->get_inverse_mass() + frictionDirectionWorld.dot(vec);
}
*/
real_t relaxation = 1.f;
m_jacDiagABInv = relaxation/(denom0+denom1);
}
real_t VehicleBody::_calc_rolling_friction(btVehicleWheelContactPoint& contactPoint) {
real_t j1=0.f;
const Vector3& contactPosWorld = contactPoint.m_frictionPositionWorld;
Vector3 rel_pos1 = contactPosWorld - contactPoint.m_s->get_transform().origin;
Vector3 rel_pos2;
if (contactPoint.m_body1)
rel_pos2 = contactPosWorld - contactPoint.m_body1->get_global_transform().origin;
real_t maxImpulse = contactPoint.m_maxImpulse;
Vector3 vel1 = contactPoint.m_s->get_linear_velocity() + (contactPoint.m_s->get_angular_velocity()).cross(rel_pos1);// * mPos);
Vector3 vel2;
if (contactPoint.m_body1) {
vel2=contactPoint.m_body1->get_linear_velocity() + contactPoint.m_body1->get_angular_velocity().cross(rel_pos2);
}
Vector3 vel = vel1 - vel2;
real_t vrel = contactPoint.m_frictionDirectionWorld.dot(vel);
// calculate j that moves us to zero relative velocity
j1 = -vrel * contactPoint.m_jacDiagABInv;
return CLAMP(j1,-maxImpulse,maxImpulse);
}
static const real_t sideFrictionStiffness2 = real_t(1.0);
void VehicleBody::_update_friction(PhysicsDirectBodyState *s) {
//calculate the impulse, so that the wheels don't move sidewards
int numWheel = wheels.size();
if (!numWheel)
return;
m_forwardWS.resize(numWheel);
m_axle.resize(numWheel);
m_forwardImpulse.resize(numWheel);
m_sideImpulse.resize(numWheel);
int numWheelsOnGround = 0;
//collapse all those loops into one!
for (int i=0;i<wheels.size();i++)
{
VehicleWheel& wheelInfo = *wheels[i];
if (wheelInfo.m_raycastInfo.m_isInContact)
numWheelsOnGround++;
m_sideImpulse[i] = real_t(0.);
m_forwardImpulse[i] = real_t(0.);
}
{
for (int i=0;i<wheels.size();i++)
{
VehicleWheel& wheelInfo = *wheels[i];
if (wheelInfo.m_raycastInfo.m_isInContact)
{
//const btTransform& wheelTrans = getWheelTransformWS( i );
Matrix3 wheelBasis0 = wheelInfo.m_worldTransform.basis;//get_global_transform().basis;
m_axle[i] = wheelBasis0.get_axis(Vector3::AXIS_X);
//m_axle[i] = wheelInfo.m_raycastInfo.m_wheelAxleWS;
const Vector3& surfNormalWS = wheelInfo.m_raycastInfo.m_contactNormalWS;
real_t proj = m_axle[i].dot(surfNormalWS);
m_axle[i] -= surfNormalWS * proj;
m_axle[i] = m_axle[i].normalized();
m_forwardWS[i] = surfNormalWS.cross(m_axle[i]);
m_forwardWS[i].normalize();
_resolve_single_bilateral(s, wheelInfo.m_raycastInfo.m_contactPointWS,
wheelInfo.m_raycastInfo.m_groundObject, wheelInfo.m_raycastInfo.m_contactPointWS,
m_axle[i],m_sideImpulse[i]);
m_sideImpulse[i] *= sideFrictionStiffness2;
}
}
}
real_t sideFactor = real_t(1.);
real_t fwdFactor = 0.5;
bool sliding = false;
{
for (int wheel =0;wheel <wheels.size();wheel++)
{
VehicleWheel& wheelInfo = *wheels[wheel];
//class btRigidBody* groundObject = (class btRigidBody*) wheelInfo.m_raycastInfo.m_groundObject;
real_t rollingFriction = 0.f;
if (wheelInfo.m_raycastInfo.m_isInContact)
{
if (engine_force != 0.f)
{
rollingFriction = -engine_force* s->get_step();
} else
{
real_t defaultRollingFrictionImpulse = 0.f;
float cbrake = MAX(wheelInfo.m_brake,brake);
real_t maxImpulse = cbrake ? cbrake : defaultRollingFrictionImpulse;
btVehicleWheelContactPoint contactPt(s,wheelInfo.m_raycastInfo.m_groundObject,wheelInfo.m_raycastInfo.m_contactPointWS,m_forwardWS[wheel],maxImpulse);
rollingFriction = _calc_rolling_friction(contactPt);
}
}
//switch between active rolling (throttle), braking and non-active rolling friction (no throttle/break)
m_forwardImpulse[wheel] = real_t(0.);
wheelInfo.m_skidInfo= real_t(1.);
if (wheelInfo.m_raycastInfo.m_isInContact)
{
wheelInfo.m_skidInfo= real_t(1.);
real_t maximp = wheelInfo.m_wheelsSuspensionForce * s->get_step() * wheelInfo.m_frictionSlip;
real_t maximpSide = maximp;
real_t maximpSquared = maximp * maximpSide;
m_forwardImpulse[wheel] = rollingFriction;//wheelInfo.m_engineForce* timeStep;
real_t x = (m_forwardImpulse[wheel] ) * fwdFactor;
real_t y = (m_sideImpulse[wheel] ) * sideFactor;
real_t impulseSquared = (x*x + y*y);
if (impulseSquared > maximpSquared)
{
sliding = true;
real_t factor = maximp / Math::sqrt(impulseSquared);
wheelInfo.m_skidInfo *= factor;
}
}
}
}
if (sliding)
{
for (int wheel = 0;wheel < wheels.size(); wheel++)
{
if (m_sideImpulse[wheel] != real_t(0.))
{
if (wheels[wheel]->m_skidInfo< real_t(1.))
{
m_forwardImpulse[wheel] *= wheels[wheel]->m_skidInfo;
m_sideImpulse[wheel] *= wheels[wheel]->m_skidInfo;
}
}
}
}
// apply the impulses
{
for (int wheel = 0;wheel<wheels.size(); wheel++)
{
VehicleWheel& wheelInfo = *wheels[wheel];
Vector3 rel_pos = wheelInfo.m_raycastInfo.m_contactPointWS -
s->get_transform().origin;
if (m_forwardImpulse[wheel] != real_t(0.))
{
s->apply_impulse(rel_pos,m_forwardWS[wheel]*(m_forwardImpulse[wheel]));
}
if (m_sideImpulse[wheel] != real_t(0.))
{
PhysicsBody* groundObject = wheelInfo.m_raycastInfo.m_groundObject;
Vector3 rel_pos2;
if (groundObject) {
rel_pos2=wheelInfo.m_raycastInfo.m_contactPointWS - groundObject->get_global_transform().origin;
}
Vector3 sideImp = m_axle[wheel] * m_sideImpulse[wheel];
#if defined ROLLING_INFLUENCE_FIX // fix. It only worked if car's up was along Y - VT.
Vector3 vChassisWorldUp = s->get_transform().basis.transposed()[1];//getRigidBody()->getCenterOfMassTransform().getBasis().getColumn(m_indexUpAxis);
rel_pos -= vChassisWorldUp * (vChassisWorldUp.dot(rel_pos) * (1.f-wheelInfo.m_rollInfluence));
#else
rel_pos[1] *= wheelInfo.m_rollInfluence; //?
#endif
s->apply_impulse(rel_pos,sideImp);
//apply friction impulse on the ground
//todo
//groundObject->applyImpulse(-sideImp,rel_pos2);
}
}
}
}
void VehicleBody::_direct_state_changed(Object *p_state) {
PhysicsDirectBodyState *s = p_state->cast_to<PhysicsDirectBodyState>();
set_ignore_transform_notification(true);
set_global_transform(s->get_transform());
set_ignore_transform_notification(false);
float step = s->get_step();
for(int i=0;i<wheels.size();i++) {
_update_wheel(i,s);
}
for(int i=0;i<wheels.size();i++) {
_ray_cast(i,s);
wheels[i]->set_transform(s->get_transform().inverse() * wheels[i]->m_worldTransform);
}
_update_suspension(s);
for(int i=0;i<wheels.size();i++) {
//apply suspension force
VehicleWheel& wheel = *wheels[i];
real_t suspensionForce = wheel.m_wheelsSuspensionForce;
if (suspensionForce > wheel.m_maxSuspensionForce)
{
suspensionForce = wheel.m_maxSuspensionForce;
}
Vector3 impulse = wheel.m_raycastInfo.m_contactNormalWS * suspensionForce * step;
Vector3 relpos = wheel.m_raycastInfo.m_contactPointWS - s->get_transform().origin;
s->apply_impulse(relpos,impulse);
//getRigidBody()->applyImpulse(impulse, relpos);
}
_update_friction(s);
for (int i=0;i<wheels.size();i++)
{
VehicleWheel& wheel = *wheels[i];
Vector3 relpos = wheel.m_raycastInfo.m_hardPointWS - s->get_transform().origin;
Vector3 vel = s->get_linear_velocity() + (s->get_angular_velocity()).cross(relpos);// * mPos);
if (wheel.m_raycastInfo.m_isInContact)
{
const Transform& chassisWorldTransform = s->get_transform();
Vector3 fwd (
chassisWorldTransform.basis[0][Vector3::AXIS_Z],
chassisWorldTransform.basis[1][Vector3::AXIS_Z],
chassisWorldTransform.basis[2][Vector3::AXIS_Z]);
real_t proj = fwd.dot(wheel.m_raycastInfo.m_contactNormalWS);
fwd -= wheel.m_raycastInfo.m_contactNormalWS * proj;
real_t proj2 = fwd.dot(vel);
wheel.m_deltaRotation = (proj2 * step) / (wheel.m_wheelRadius);
wheel.m_rotation += wheel.m_deltaRotation;
} else
{
wheel.m_rotation += wheel.m_deltaRotation;
}
wheel.m_deltaRotation *= real_t(0.99);//damping of rotation when not in contact
}
linear_velocity = s->get_linear_velocity();
}
void VehicleBody::set_mass(real_t p_mass) {
mass=p_mass;
PhysicsServer::get_singleton()->body_set_param(get_rid(),PhysicsServer::BODY_PARAM_MASS,mass);
}
real_t VehicleBody::get_mass() const{
return mass;
}
void VehicleBody::set_friction(real_t p_friction) {
friction=p_friction;
PhysicsServer::get_singleton()->body_set_param(get_rid(),PhysicsServer::BODY_PARAM_FRICTION,friction);
}
real_t VehicleBody::get_friction() const{
return friction;
}
void VehicleBody::set_engine_force(float p_force) {
engine_force=p_force;
}
float VehicleBody::get_engine_force() const{
return engine_force;
}
void VehicleBody::set_brake(float p_brake){
brake=p_brake;
}
float VehicleBody::get_brake() const{
return brake;
}
void VehicleBody::set_steering(float p_steering){
m_steeringValue=p_steering;
}
float VehicleBody::get_steering() const{
return m_steeringValue;
}
Vector3 VehicleBody::get_linear_velocity() const
{
return linear_velocity;
}
void VehicleBody::_bind_methods(){
ObjectTypeDB::bind_method(_MD("set_mass","mass"),&VehicleBody::set_mass);
ObjectTypeDB::bind_method(_MD("get_mass"),&VehicleBody::get_mass);
ObjectTypeDB::bind_method(_MD("set_friction","friction"),&VehicleBody::set_friction);
ObjectTypeDB::bind_method(_MD("get_friction"),&VehicleBody::get_friction);
ObjectTypeDB::bind_method(_MD("set_engine_force","engine_force"),&VehicleBody::set_engine_force);
ObjectTypeDB::bind_method(_MD("get_engine_force"),&VehicleBody::get_engine_force);
ObjectTypeDB::bind_method(_MD("set_brake","brake"),&VehicleBody::set_brake);
ObjectTypeDB::bind_method(_MD("get_brake"),&VehicleBody::get_brake);
ObjectTypeDB::bind_method(_MD("set_steering","steering"),&VehicleBody::set_steering);
ObjectTypeDB::bind_method(_MD("get_steering"),&VehicleBody::get_steering);
ObjectTypeDB::bind_method(_MD("get_linear_velocity"),&VehicleBody::get_linear_velocity);
ObjectTypeDB::bind_method(_MD("_direct_state_changed"),&VehicleBody::_direct_state_changed);
ADD_PROPERTY( PropertyInfo(Variant::REAL,"motion/engine_force",PROPERTY_HINT_RANGE,"0.00,1024.0,0.01"),_SCS("set_engine_force"),_SCS("get_engine_force"));
ADD_PROPERTY( PropertyInfo(Variant::REAL,"motion/brake",PROPERTY_HINT_RANGE,"0.0,1.0,0.01"),_SCS("set_brake"),_SCS("get_brake"));
ADD_PROPERTY( PropertyInfo(Variant::REAL,"motion/steering",PROPERTY_HINT_RANGE,"-180,180.0,0.01"),_SCS("set_steering"),_SCS("get_steering"));
ADD_PROPERTY( PropertyInfo(Variant::REAL,"body/mass",PROPERTY_HINT_RANGE,"0.01,65536,0.01"),_SCS("set_mass"),_SCS("get_mass"));
ADD_PROPERTY( PropertyInfo(Variant::REAL,"body/friction",PROPERTY_HINT_RANGE,"0.01,1,0.01"),_SCS("set_friction"),_SCS("get_friction"));
}
VehicleBody::VehicleBody() : PhysicsBody(PhysicsServer::BODY_MODE_RIGID) {
m_pitchControl=0;
m_currentVehicleSpeedKmHour = real_t(0.);
m_steeringValue = real_t(0.);
engine_force=0;
brake=0;
friction=1;
ccd=false;
exclude.insert(get_rid());
PhysicsServer::get_singleton()->body_set_force_integration_callback(get_rid(),this,"_direct_state_changed");
set_mass(40);
}