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

Browse Source 
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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7
Demos/OpenGL/DemoApplication.cpp
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@@ -368,6 +368,13 @@ void DemoApplication::keyboardCallback(unsigned char key, int x, int y)
}
void DemoApplication::specialKeyboardUp(int key, int x, int y)
{
glutPostRedisplay();
}
void DemoApplication::specialKeyboard(int key, int x, int y)
{
(void)x;

2
Demos/OpenGL/DemoApplication.h
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@@ -155,6 +155,8 @@ public:
virtual void specialKeyboard(int key, int x, int y);
virtual void specialKeyboardUp(int key, int x, int y);
virtual void reshape(int w, int h);
virtual void mouseFunc(int button, int state, int x, int y);

8
Demos/OpenGL/GlutStuff.cpp
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@@ -32,6 +32,12 @@ static void glutSpecialKeyboardCallback(int key, int x, int y)
gDemoApplication->specialKeyboard(key,x,y);
}
static void glutSpecialKeyboardUpCallback(int key, int x, int y)
{
gDemoApplication->specialKeyboardUp(key,x,y);
}
static void glutReshapeCallback(int w, int h)
{
gDemoApplication->reshape(w,h);
@@ -75,6 +81,8 @@ int glutmain(int argc, char **argv,int width,int height,const char* title,DemoAp
glutKeyboardFunc(glutKeyboardCallback);
glutSpecialFunc(glutSpecialKeyboardCallback);
glutSpecialUpFunc(glutSpecialKeyboardUpCallback);
glutReshapeFunc(glutReshapeCallback);
//createMenu();
glutIdleFunc(glutMoveAndDisplayCallback);

76
Demos/VehicleDemo/VehicleDemo.cpp
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@@ -55,13 +55,17 @@ const int maxOverlap = 65535;
///notice that for higher-quality slow-moving vehicles, another approach might be better
///implementing explicit hinged-wheel constraints with cylinder collision, rather then raycasts
float gEngineForce = 0.f;
float maxEngineForce = 3000.f;
float gBreakingForce = 0.f;
float maxEngineForce = 1000.f;//this should be engine/velocity dependent
float maxBreakingForce = 100.f;
float gVehicleSteering = 0.f;
float steeringIncrement = 0.04f;
float steeringClamp = 0.3f;
float wheelRadius = 0.5f;
float wheelWidth = 0.4f;
float wheelFriction = 1e30f;//1000;//1e30f;
float wheelFriction = 1000;//1e30f;
float suspensionStiffness = 20.f;
float suspensionDamping = 2.3f;
float suspensionCompression = 4.4f;
@@ -103,6 +107,10 @@ m_maxCameraDistance(10.f)
void VehicleDemo::setupPhysics()
{
extern btScalar gJitterVelocityDampingFactor;
gJitterVelocityDampingFactor = 1.f;
#ifdef FORCE_ZAXIS_UP
m_cameraUp = btVector3(0,0,1);
m_forwardAxis = 1;
@@ -147,7 +155,8 @@ const float TRIANGLE_SIZE=20.f;
for (int j=0;j<NUM_VERTS_Y;j++)
{
float wl = .2f;
float height = 20.f*sinf(float(i)*wl)*cosf(float(j)*wl);
//height set to zero, but can also use curved landscape, just uncomment out the code
float height = 0.f;//20.f*sinf(float(i)*wl)*cosf(float(j)*wl);
#ifdef FORCE_ZAXIS_UP
gVertices[i+j*NUM_VERTS_X].setValue(
(i-NUM_VERTS_X*0.5f)*TRIANGLE_SIZE,
@@ -222,7 +231,7 @@ const float TRIANGLE_SIZE=20.f;
tr.setOrigin(btVector3(0,0.f,0));
m_carChassis = localCreateRigidBody(800,tr,compound);//chassisShape);
m_carChassis->setDamping(0.2,0.2);
//m_carChassis->setDamping(0.2,0.2);
clientResetScene();
@@ -323,6 +332,24 @@ void VehicleDemo::clientMoveAndDisplay()
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
{
int wheelIndex = 2;
m_vehicle->applyEngineForce(gEngineForce,wheelIndex);
m_vehicle->setBrake(gBreakingForce,wheelIndex);
wheelIndex = 3;
m_vehicle->applyEngineForce(gEngineForce,wheelIndex);
m_vehicle->setBrake(gBreakingForce,wheelIndex);
wheelIndex = 0;
m_vehicle->setSteeringValue(gVehicleSteering,wheelIndex);
wheelIndex = 1;
m_vehicle->setSteeringValue(gVehicleSteering,wheelIndex);
}
float dt = m_clock.getTimeMicroseconds() * 0.000001f;
m_clock.reset();
if (m_dynamicsWorld)
@@ -334,7 +361,7 @@ void VehicleDemo::clientMoveAndDisplay()
int numSimSteps = m_dynamicsWorld->stepSimulation(dt,maxSimSubSteps);
#define VERBOSE_FEEDBACK
//#define VERBOSE_FEEDBACK
#ifdef VERBOSE_FEEDBACK
if (!numSimSteps)
printf("Interpolated transforms\n");
@@ -356,18 +383,6 @@ void VehicleDemo::clientMoveAndDisplay()
{
int wheelIndex = 2;
m_vehicle->applyEngineForce(gEngineForce,wheelIndex);
wheelIndex = 3;
m_vehicle->applyEngineForce(gEngineForce,wheelIndex);
wheelIndex = 0;
m_vehicle->setSteeringValue(gVehicleSteering,wheelIndex);
wheelIndex = 1;
m_vehicle->setSteeringValue(gVehicleSteering,wheelIndex);
}
@@ -417,7 +432,6 @@ void VehicleDemo::displayCallback(void)
void VehicleDemo::clientResetScene()
{
gEngineForce = 0.f;
gVehicleSteering = 0.f;
m_carChassis->setCenterOfMassTransform(btTransform::getIdentity());
m_carChassis->setLinearVelocity(btVector3(0,0,0));
@@ -437,10 +451,32 @@ void VehicleDemo::clientResetScene()
void VehicleDemo::specialKeyboardUp(int key, int x, int y)
{
switch (key)
{
case GLUT_KEY_UP :
{
gEngineForce = 0.f;
break;
}
case GLUT_KEY_DOWN :
{
gBreakingForce = 0.f;
break;
}
default:
DemoApplication::specialKeyboardUp(key,x,y);
break;
}
}
void VehicleDemo::specialKeyboard(int key, int x, int y)
{
printf("key = %i x=%i y=%i\n",key,x,y);
// printf("key = %i x=%i y=%i\n",key,x,y);
switch (key)
{
@@ -467,7 +503,7 @@ void VehicleDemo::specialKeyboard(int key, int x, int y)
}
case GLUT_KEY_DOWN :
{
gEngineForce = -maxEngineForce;
gBreakingForce = maxBreakingForce;
break;
}
default:

2
Demos/VehicleDemo/VehicleDemo.h
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@@ -51,6 +51,8 @@ class VehicleDemo : public DemoApplication
virtual void specialKeyboard(int key, int x, int y);
virtual void specialKeyboardUp(int key, int x, int y);
void renderme();
void setupPhysics();

3
Glut/GL/glut.h
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@@ -91,7 +91,8 @@ extern "C" {
glutJoystickFunc, glutForceJoystickFunc (NOT FINALIZED!).
**/
#ifndef GLUT_API_VERSION /* allow this to be overriden */
#define GLUT_API_VERSION 3
//#define GLUT_API_VERSION 3
#define GLUT_API_VERSION 4
#endif
/**

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
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@@ -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;