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Fix (needs more testing) in btRigidBody::setCenterOfMassTransform, assign m_interpolationWorldTransform = xform; instead of m_worldTransform;

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Thanks Jay for reporting
Added braking capability to btRaycastVehicle, see Bullet/Demos/VehicleDemo/VehicleDemo.cpp
Added glutKeyboardUpFunc, for vehicle demo (keep accelerating/breaking, until key released/UP). Hope this is compatible with most GLUT implementations.
This commit is contained in:
ejcoumans
2007-04-22 15:23:20 +00:00
parent bc3f9535ad
commit 2db8bfa3d6
8 changed files with 158 additions and 23 deletions
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2
src/BulletDynamics/Dynamics/btRigidBody.cpp
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@@ -297,7 +297,7 @@ btQuaternion btRigidBody::getOrientation() const
void btRigidBody::setCenterOfMassTransform(const btTransform& xform)
{
m_interpolationWorldTransform = m_worldTransform;
m_interpolationWorldTransform = xform;//m_worldTransform;
m_interpolationLinearVelocity = getLinearVelocity();
m_interpolationAngularVelocity = getAngularVelocity();
m_worldTransform = xform;

81
src/BulletDynamics/Vehicle/btRaycastVehicle.cpp
View File

@@ -18,6 +18,7 @@
#include "BulletDynamics/Dynamics/btDynamicsWorld.h"
#include "btVehicleRaycaster.h"
#include "btWheelInfo.h"
#include "LinearMath/btMinMax.h"
#include "BulletDynamics/ConstraintSolver/btContactConstraint.h"
@@ -458,6 +459,63 @@ void btRaycastVehicle::updateSuspension(btScalar deltaTime)
}
struct btWheelContactPoint
{
btRigidBody* m_body0;
btRigidBody* m_body1;
btVector3 m_frictionPositionWorld;
btVector3 m_frictionDirectionWorld;
btScalar m_jacDiagABInv;
btScalar m_maxImpulse;
btWheelContactPoint(btRigidBody* body0,btRigidBody* body1,const btVector3& frictionPosWorld,const btVector3& frictionDirectionWorld, btScalar maxImpulse)
:m_body0(body0),
m_body1(body1),
m_frictionPositionWorld(frictionPosWorld),
m_frictionDirectionWorld(frictionDirectionWorld),
m_maxImpulse(maxImpulse)
{
btScalar denom0 = body0->computeImpulseDenominator(frictionPosWorld,frictionDirectionWorld);
btScalar denom1 = body1->computeImpulseDenominator(frictionPosWorld,frictionDirectionWorld);
btScalar relaxation = 1.f;
m_jacDiagABInv = relaxation/(denom0+denom1);
}
};
btScalar calcRollingFriction(btWheelContactPoint& contactPoint)
{
btScalar j1=0.f;
const btVector3& contactPosWorld = contactPoint.m_frictionPositionWorld;
btVector3 rel_pos1 = contactPosWorld - contactPoint.m_body0->getCenterOfMassPosition();
btVector3 rel_pos2 = contactPosWorld - contactPoint.m_body1->getCenterOfMassPosition();
btScalar maxImpulse = contactPoint.m_maxImpulse;
btVector3 vel1 = contactPoint.m_body0->getVelocityInLocalPoint(rel_pos1);
btVector3 vel2 = contactPoint.m_body1->getVelocityInLocalPoint(rel_pos2);
btVector3 vel = vel1 - vel2;
btScalar vrel = contactPoint.m_frictionDirectionWorld.dot(vel);
// calculate j that moves us to zero relative velocity
j1 = -vrel * contactPoint.m_jacDiagABInv;
GEN_set_min(j1, maxImpulse);
GEN_set_max(j1, -maxImpulse);
return j1;
}
btScalar sideFrictionStiffness2 = btScalar(1.0);
void btRaycastVehicle::updateFriction(btScalar timeStep)
{
@@ -539,6 +597,26 @@ void btRaycastVehicle::updateFriction(btScalar timeStep)
btWheelInfo& wheelInfo = m_wheelInfo[wheel];
class btRigidBody* groundObject = (class btRigidBody*) wheelInfo.m_raycastInfo.m_groundObject;
btScalar rollingFriction = 0.f;
if (groundObject)
{
if (wheelInfo.m_engineForce != 0.f)
{
rollingFriction = wheelInfo.m_engineForce* timeStep;
} else
{
btScalar defaultRollingFrictionImpulse = 0.f;
btScalar maxImpulse = wheelInfo.m_brake ? wheelInfo.m_brake : defaultRollingFrictionImpulse;
btWheelContactPoint contactPt(m_chassisBody,groundObject,wheelInfo.m_raycastInfo.m_contactPointWS,forwardWS[wheel],maxImpulse);
rollingFriction = calcRollingFriction(contactPt);
}
}
//switch between active rolling (throttle), braking and non-active rolling friction (no throttle/break)
forwardImpulse[wheel] = btScalar(0.);
m_wheelInfo[wheel].m_skidInfo= btScalar(1.);
@@ -551,8 +629,9 @@ void btRaycastVehicle::updateFriction(btScalar timeStep)
btScalar maximpSide = maximp;
btScalar maximpSquared = maximp * maximpSide;
forwardImpulse[wheel] = wheelInfo.m_engineForce* timeStep;
forwardImpulse[wheel] = rollingFriction;//wheelInfo.m_engineForce* timeStep;
btScalar x = (forwardImpulse[wheel] ) * fwdFactor;
btScalar y = (sideImpulse[wheel] ) * sideFactor;