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OpenGL OpenGL and PhysiX library simulation problem

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Hi everyone, i was wondering if you can help me out with a problem i am facing. Well i know that i am not good neither in opengl nor on physx, but i was eager to give it a try. What i was hoping to do is to make a simulation where there is a rectangular cuboid in the scene which has one side transparent(so we can see what's happening inside) and inside that rectangular there are two cubes and two spheres which are starting from an initial position and then forces are applied to those objects and they start collide with each other and the surrounding environment, in this case the rectangular cuboid. All i have done so far is take one sample of the physx sdk and add couple of lines to draw two cubes and two spheres. What i don't know is how to put those inside a rectangular cuboid and apply forces to them to make them collide. I have attached an image of what the simulation looks like now.
I could appreciate any kind of help at all. Thank you all and god bless you.

here is the code for the header files

Lesson101.h



#ifndef LESSON101_H
#define LESSON101_H

#include <GL/glut.h>

#include <stdio.h>

#include "NxPhysics.h"
#include "DrawObjects.h"
#include "HUD.h"

#include "DebugRenderer.h"
#include "CommonCode.h"

void PrintControls();
void ProcessCameraKeys();
void SetupCamera();
void RenderActors(bool shadows);
void DrawForce(NxActor* actor, NxVec3& forceVec, const NxVec3& color);

NxVec3 ApplyForceToActor(NxActor* actor, const NxVec3& forceDir, const NxReal forceStrength);
void ProcessForceKeys();
void ProcessInputs();
void SelectNextActor();
bool IsSelectable(NxActor* actor);

void RenderCallback();
void ReshapeCallback(int width, int height);
void IdleCallback();
void KeyboardCallback(unsigned char key, int x, int y);
void KeyboardUpCallback(unsigned char key, int x, int y);
void SpecialCallback(int key, int x, int y);
void MouseCallback(int button, int state, int x, int y);
void MotionCallback(int x, int y);
void ExitCallback();
void InitGlut(int argc, char** argv);

NxActor* CreateGroundPlane();
NxActor* CreateBox();
NxActor* CreateSphere();
NxActor* CreateCapsule();
NxActor* CreateBounds3();
NxActor* CreateSegment();
NxActor* CreateRay();

void InitializeHUD();

void InitNx();
void ReleaseNx();
void ResetNx();

void StartPhysics();
void GetPhysicsResults();

int main(int argc, char** argv);

#endif // LESSON101_H




DrawObjects.h


#ifndef DRAWOBJECTS_H
#define DRAWOBJECTS_H

class NxShape;
class NxActor;

void SetupGLMatrix(const NxVec3& pos, const NxMat33& orient);
void DrawLine(const NxVec3& p0, const NxVec3& p1, const NxVec3& color, float lineWidth=2.0f);
void DrawTriangle(const NxVec3& p0, const NxVec3& p1, const NxVec3& p2, const NxVec3& color);
void DrawCircle(NxU32 nbSegments, const NxMat34& matrix, const NxVec3& color, const NxF32 radius, const bool semicircle = false);
void DrawEllipse(NxU32 nbSegments, const NxMat34& matrix, const NxVec3& color, const NxF32 radius1, const NxF32 radius2, const bool semicircle = false);

void DrawWirePlane(NxShape* plane, const NxVec3& color);
void DrawPlane(NxShape* plane);

void DrawWireBox(NxShape* box, const NxVec3& color, float lineWidth=2.0f);
void DrawWireBox(const NxBox& obb, const NxVec3& color, float lineWidth=2.0f);
void DrawBox(NxShape* box);

void DrawWireSphere(NxShape* sphere, const NxVec3& color);
void DrawWireSphere(NxSphere* sphere, const NxVec3& color);
void DrawSphere(NxShape* sphere);

void DrawWireCapsule(NxShape* capsule, const NxVec3& color);
void DrawWireCapsule(const NxCapsule& capsule, const NxVec3& color);
void DrawCapsule(NxShape* capsule);
void DrawCapsule(const NxVec3& color, NxF32 r, NxF32 h);

void DrawWireConvex(NxShape* mesh, const NxVec3& color, bool useShapeUserData);
void DrawConvex(NxShape* mesh, bool useShapeUserData);

void DrawWireMesh(NxShape* mesh, const NxVec3& color, bool useShapeUserData);
void DrawMesh(NxShape* mesh, bool useShapeUserData);
void DrawWheelShape(NxShape* wheel);

void DrawArrow(const NxVec3& posA, const NxVec3& posB, const NxVec3& color);
void DrawContactPoint(const NxVec3& pos, const NxReal radius, const NxVec3& color);

void DrawWireShape(NxShape* shape, const NxVec3& color, bool useShapeUserData);
void DrawShape(NxShape* shape, bool useShapeUserData);
void DrawActor(NxActor* actor, NxActor* selectedActor, bool useShapeUserData);
void DrawActorShadow(NxActor* actor, bool useShapeUserData);
void DrawActorShadow2(NxActor* actor, bool useShapeUserData);
void DrawActorShadowZUp(NxActor* actor, bool useShapeUserData);

void DrawCloth(NxCloth *cloth,bool shadows);

void DrawActorShapeSelect(NxActor* actor, NxShape* shape, const bool shapeSelectMode, NxActor* selectedActor, bool useShapeUserData);


#endif // DRAWOBJECTS_H




HUD.h


#ifndef HUD_H
#define HUD_H

#include <GL/glut.h>
#include <stdio.h>

#include "NxPhysics.h"

class DisplayString
{
public:
char m_string[512];
NxReal m_xpos;
NxReal m_ypos;

DisplayString()
{
m_string[0]='\0';
m_ypos = m_xpos = 0;
}

void Set(char* s, NxReal x, NxReal y)
{
sprintf(m_string, s);
m_xpos = x;
m_ypos = y;
}
};

class HUD
{
public:
NxArray<DisplayString> m_DisplayString;

void AddDisplayString(char* s, NxReal x, NxReal y);
void SetDisplayString(NxU32 i, char* s, NxReal x, NxReal y);
void Clear();
void Render();
};
#endif // HUD_H




here is the actual .cpp file Lesson101.cpp


// ===============================================================================
// NVIDIA PHYSX SDK TRAINING PROGRAMS
// LESSON 101 : PRIMARY SHAPE
//
// Written by QA BJ, 6-2-2008
// ===============================================================================

#include "Lesson101.h"
#include "UpdateTime.h"

// Physics SDK globals
NxPhysicsSDK* gPhysicsSDK = NULL;
NxScene* gScene = NULL;
NxVec3 gDefaultGravity(0,-9.8,0);

// User report globals
DebugRenderer gDebugRenderer;

// HUD globals
HUD hud;

// Display globals
int gMainHandle;
int mx = 0;
int my = 0;

// Camera globals
float gCameraAspectRatio = 1.0f;
NxVec3 gCameraPos(0,5,-15);
NxVec3 gCameraForward(0,0,1);
NxVec3 gCameraRight(-1,0,0);
const NxReal gCameraSpeed = 10;

// Force globals
NxVec3 gForceVec(0,0,0);
NxReal gForceStrength = 20000;
bool bForceMode = true;

// Keyboard globals
#define MAX_KEYS 256
bool gKeys[MAX_KEYS];

// Simulation globals
NxReal gDeltaTime = 1.0/60.0;
bool bHardwareScene = false;
bool bPause = false;
bool bShadows = true;
bool bDebugWireframeMode = false;

// Actor globals
NxActor* groundPlane = NULL;

// Focus actor
NxActor* gSelectedActor = NULL;

void PrintControls()
{
printf("\n Flight Controls:\n ----------------\n w = forward, s = back\n a = strafe left, d = strafe right\n q = up, z = down\n");
printf("\n Force Controls:\n ---------------\n i = +z, k = -z\n j = +x, l = -x\n u = +y, m = -y\n");
printf("\n Miscellaneous:\n --------------\n p = Pause\n b = Toggle Debug Wireframe Mode\n x = Toggle Shadows\n r = Select Actor\n F10 = Reset scene\n");
}

NxVec3 ApplyForceToActor(NxActor* actor, const NxVec3& forceDir, const NxReal forceStrength)
{
NxVec3 forceVec = forceStrength*forceDir*gDeltaTime;
actor->addForce(forceVec);
return forceVec;
}

void ProcessCameraKeys()
{
NxReal deltaTime;

if (bPause)
{
deltaTime = 0.0005;
}
else
{
deltaTime = gDeltaTime;
}

// Process camera keys
for (int i = 0; i < MAX_KEYS; i++)
{
if (!gKeys) { continue; }

switch (i)
{
// Camera controls
case 'w':{ gCameraPos += gCameraForward*gCameraSpeed*deltaTime; break; }
case 's':{ gCameraPos -= gCameraForward*gCameraSpeed*deltaTime; break; }
case 'a':{ gCameraPos -= gCameraRight*gCameraSpeed*deltaTime; break; }
case 'd':{ gCameraPos += gCameraRight*gCameraSpeed*deltaTime; break; }
case 'z':{ gCameraPos -= NxVec3(0,1,0)*gCameraSpeed*deltaTime; break; }
case 'q':{ gCameraPos += NxVec3(0,1,0)*gCameraSpeed*deltaTime; break; }
}
}
}

void SetupCamera()
{
gCameraAspectRatio = (float)glutGet(GLUT_WINDOW_WIDTH) / (float)glutGet(GLUT_WINDOW_HEIGHT);

// Setup camera
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0f, gCameraAspectRatio, 1.0f, 10000.0f);
gluLookAt(gCameraPos.x,gCameraPos.y,gCameraPos.z,gCameraPos.x + gCameraForward.x, gCameraPos.y + gCameraForward.y, gCameraPos.z + gCameraForward.z, 0.0f, 1.0f, 0.0f);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

void RenderActors(bool shadows)
{
// Render all the actors in the scene
NxU32 nbActors = gScene->getNbActors();
NxActor** actors = gScene->getActors();
while (nbActors--)
{
NxActor* actor = *actors++;
DrawActor(actor, gSelectedActor, false);

// Handle shadows
if (shadows)
{
DrawActorShadow(actor, false);
}
}
}

void DrawForce(NxActor* actor, NxVec3& forceVec, const NxVec3& color)
{
// Draw only if the force is large enough
NxReal force = forceVec.magnitude();
if (force < 0.1) return;

forceVec = 3*forceVec/force;

NxVec3 pos = actor->getCMassGlobalPosition();
DrawArrow(pos, pos + forceVec, color);
}

bool IsSelectable(NxActor* actor)
{
NxShape*const* shapes = gSelectedActor->getShapes();
NxU32 nShapes = gSelectedActor->getNbShapes();
while (nShapes--)
{
if (shapes[nShapes]->getFlag(NX_TRIGGER_ENABLE))
{
return false;
}
}

if(!actor->isDynamic())
return false;

if (actor == groundPlane)
return false;

return true;
}

void SelectNextActor()
{
NxU32 nbActors = gScene->getNbActors();
NxActor** actors = gScene->getActors();
for(NxU32 i = 0; i < nbActors; i++)
{
if (actors == gSelectedActor)
{
NxU32 j = 1;
gSelectedActor = actors[(i+j)%nbActors];
while (!IsSelectable(gSelectedActor))
{
j++;
gSelectedActor = actors[(i+j)%nbActors];
}
break;
}
}
}

void ProcessForceKeys()
{
// Process force keys
for (int i = 0; i < MAX_KEYS; i++)
{
if (!gKeys) { continue; }

switch (i)
{
// Force controls
case 'i': { gForceVec = ApplyForceToActor(gSelectedActor,NxVec3(0,0,1),gForceStrength); break; }
case 'k': { gForceVec = ApplyForceToActor(gSelectedActor,NxVec3(0,0,-1),gForceStrength); break; }
case 'j': { gForceVec = ApplyForceToActor(gSelectedActor,NxVec3(1,0,0),gForceStrength); break; }
case 'l': { gForceVec = ApplyForceToActor(gSelectedActor,NxVec3(-1,0,0),gForceStrength); break; }
case 'u': { gForceVec = ApplyForceToActor(gSelectedActor,NxVec3(0,1,0),gForceStrength); break; }
case 'm': { gForceVec = ApplyForceToActor(gSelectedActor,NxVec3(0,-1,0),gForceStrength); break; }

// Return box to (0,5,0)
case 't':
{
if (gSelectedActor)
{
gSelectedActor->setGlobalPosition(NxVec3(0,5,0));
gScene->flushCaches();
}
break;
}
}
}
}

void ProcessInputs()
{
ProcessForceKeys();

// Show debug wireframes
if (bDebugWireframeMode)
{
if (gScene) gDebugRenderer.renderData(*gScene->getDebugRenderable());
}
}

void RenderCallback()
{
// Clear buffers
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

ProcessCameraKeys();
SetupCamera();

if (gScene && !bPause)
{
GetPhysicsResults();
ProcessInputs();
StartPhysics();
}

// Display scene
RenderActors(bShadows);

DrawForce(gSelectedActor, gForceVec, NxVec3(1,1,0));
gForceVec = NxVec3(0,0,0);

// Render the HUD
hud.Render();

glFlush();
glutSwapBuffers();
}

void ReshapeCallback(int width, int height)
{
glViewport(0, 0, width, height);
gCameraAspectRatio = float(width)/float(height);
}

void IdleCallback()
{
glutPostRedisplay();
}

void KeyboardCallback(unsigned char key, int x, int y)
{
gKeys[key] = true;

switch (key)
{
case 'r': { SelectNextActor(); break; }
default: { break; }
}
}

void KeyboardUpCallback(unsigned char key, int x, int y)
{
gKeys[key] = false;

switch (key)
{
case 'p':
{
bPause = !bPause;
if (bPause)
hud.SetDisplayString(0, "Paused - Hit \"p\" to Unpause", 0.3f, 0.55f);
else
hud.SetDisplayString(0, "", 0.0f, 0.0f);
UpdateTime();
break;
}
case 'x': { bShadows = !bShadows; break; }
case 'b': { bDebugWireframeMode = !bDebugWireframeMode; break; }
case 27 : { exit(0); break; }
default : { break; }
}
}

void SpecialCallback(int key, int x, int y)
{
switch (key)
{
// Reset PhysX
case GLUT_KEY_F10: ResetNx(); return;
}
}

void MouseCallback(int button, int state, int x, int y)
{
mx = x;
my = y;
}

void MotionCallback(int x, int y)
{
int dx = mx - x;
int dy = my - y;

gCameraForward.normalize();
gCameraRight.cross(gCameraForward,NxVec3(0,1,0));

NxQuat qx(NxPiF32 * dx * 20 / 180.0f, NxVec3(0,1,0));
qx.rotate(gCameraForward);
NxQuat qy(NxPiF32 * dy * 20 / 180.0f, gCameraRight);
qy.rotate(gCameraForward);

mx = x;
my = y;
}

void ExitCallback()
{
ReleaseNx();
}

void InitGlut(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitWindowSize(900, 700);
glutInitWindowPosition(100,100);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
gMainHandle = glutCreateWindow("Primary Shape");
glutSetWindow(gMainHandle);
glutDisplayFunc(RenderCallback);
glutReshapeFunc(ReshapeCallback);
glutIdleFunc(IdleCallback);
glutKeyboardFunc(KeyboardCallback);
glutKeyboardUpFunc(KeyboardUpCallback);
glutSpecialFunc(SpecialCallback);
glutMouseFunc(MouseCallback);
glutMotionFunc(MotionCallback);
MotionCallback(0,0);
atexit(ExitCallback);

// Setup default render states
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glEnable(GL_DEPTH_TEST);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_CULL_FACE);

// Setup lighting
glEnable(GL_LIGHTING);
float AmbientColor[] = { 0.0f, 0.1f, 0.2f, 0.0f }; glLightfv(GL_LIGHT0, GL_AMBIENT, AmbientColor);
float DiffuseColor[] = { 0.2f, 0.2f, 0.2f, 0.0f }; glLightfv(GL_LIGHT0, GL_DIFFUSE, DiffuseColor);
float SpecularColor[] = { 0.5f, 0.5f, 0.5f, 0.0f }; glLightfv(GL_LIGHT0, GL_SPECULAR, SpecularColor);
float Position[] = { 100.0f, 100.0f, -400.0f, 1.0f }; glLightfv(GL_LIGHT0, GL_POSITION, Position);
glEnable(GL_LIGHT0);
}

NxActor* CreateGroundPlane()
{
// Create a plane with default descriptor
NxPlaneShapeDesc planeDesc;
NxActorDesc actorDesc;
actorDesc.shapes.pushBack(&planeDesc);
return gScene->createActor(actorDesc);
}

NxActor* CreateBox()
{
// Set the box starting height to 3.5m so box starts off falling onto the ground
NxReal boxStartHeight = 3.5;

// Add a single-shape actor to the scene
NxActorDesc actorDesc;
NxBodyDesc bodyDesc;

// The actor has one shape, a box, 1m on a side
NxBoxShapeDesc boxDesc;
boxDesc.dimensions.set(0.5,0.5,0.5);
boxDesc.localPose.t = NxVec3(0, 0, 0);
actorDesc.shapes.pushBack(&boxDesc);

actorDesc.body = &bodyDesc;
actorDesc.density = 10.0f;
actorDesc.globalPose.t = NxVec3(0,boxStartHeight,0);
assert(actorDesc.isValid());
NxActor *pActor = gScene->createActor(actorDesc);
assert(pActor);

// //create actor with no shapes
//NxShape* const *shape = pActor->getShapes();
//NxBoxShape *boxShape = shape[0]->isBox();
//assert(boxShape);
//pActor->releaseShape(*boxShape);

//NxVec3 forceVec1 = gForceStrength*NxVec3(1,0,0)*gDeltaTime;
//NxVec3 forceVec2 = gForceStrength*NxVec3(-1,0,0)*gDeltaTime;
NxVec3 forceVec3 = gForceStrength*NxVec3(0,1,0)*gDeltaTime;
//NxVec3 forceVec4 = gForceStrength*NxVec3(0,-1,0)*gDeltaTime;
//NxVec3 forceVec5 = gForceStrength*NxVec3(0,0,1)*gDeltaTime;
//NxVec3 forceVec6 = gForceStrength*NxVec3(0,0,-1)*gDeltaTime;
//pActor->addForce(forceVec1);
//pActor->addForce(forceVec2);
pActor->addForce(forceVec3);
/*pActor->addForce(forceVec4);
pActor->addForce(forceVec5);
pActor->addForce(forceVec6);*/

/*NxVec3 ApplyForceToActor(NxActor* actor, const NxVec3& forceDir, const NxReal forceStrength)
{
NxVec3 forceVec = forceStrength*forceDir*gDeltaTime;
actor->addForce(forceVec);
return forceVec;
}
gForceVec = ApplyForceToActor(gSelectedActor,NxVec3(1,0,0),gForceStrength)*/

return pActor;
}

NxActor* CreateSphere()
{
// Set the sphere starting height to 3.5m so box starts off falling onto the ground
NxReal sphereStartHeight = 3.5;

// Add a single-shape actor to the scene
NxActorDesc actorDesc;
NxBodyDesc bodyDesc;

// The actor has one shape, a sphere, 1m on radius
NxSphereShapeDesc sphereDesc;
sphereDesc.radius = 0.65f;
sphereDesc.localPose.t = NxVec3(0, 0, 0);

actorDesc.shapes.pushBack(&sphereDesc);
actorDesc.body = &bodyDesc;
actorDesc.density = 10.0f;
actorDesc.globalPose.t = NxVec3(3.0f,sphereStartHeight,0);
return gScene->createActor(actorDesc);
}


NxActor* CreateCapsule()
{
// Set the capsule starting height to 3.5m so box starts off falling onto the ground
NxReal capsuleStartHeight = 3.5;

// Add a single-shape actor to the scene
NxActorDesc actorDesc;
NxBodyDesc bodyDesc;

// The actor has one shape, a sphere, 1m on radius
NxCapsuleShapeDesc capsuleDesc;
capsuleDesc.radius = 0.55f;
capsuleDesc.height = 0.75f;
capsuleDesc.localPose.t = NxVec3(0, 0, 0);

//Rotate capsule shape
NxQuat quat(45, NxVec3(0, 0, 1));
NxMat33 m33(quat);
capsuleDesc.localPose.M = m33;

actorDesc.shapes.pushBack(&capsuleDesc);
actorDesc.body = &bodyDesc;
actorDesc.density = 10.0f;
actorDesc.globalPose.t = NxVec3(6.0f,capsuleStartHeight,0);

////Rotate actor
//NxQuat quat1(45, NxVec3(1, 0, 0));
//NxMat33 m331(quat1);
//actorDesc.globalPose.M = m331;

return gScene->createActor(actorDesc);
}

void InitializeHUD()
{
bHardwareScene = (gScene->getSimType() == NX_SIMULATION_HW);

hud.Clear();

//// Add hardware/software to HUD
//if (bHardwareScene)
// hud.AddDisplayString("Hardware Scene", 0.74f, 0.92f);
//else
// hud.AddDisplayString("Software Scene", 0.74f, 0.92f);

// Add pause to HUD
if (bPause)
hud.AddDisplayString("Paused - Hit \"p\" to Unpause", 0.3f, 0.55f);
else
hud.AddDisplayString("", 0.0f, 0.0f);
}

void InitNx()
{
// Initialize camera parameters
gCameraAspectRatio = 1.0f;
gCameraPos = NxVec3(0,5,-15);
gCameraForward = NxVec3(0,0,1);
gCameraRight = NxVec3(-1,0,0);

// Create the physics SDK
gPhysicsSDK = NxCreatePhysicsSDK(NX_PHYSICS_SDK_VERSION);
if (!gPhysicsSDK) return;
else if(gPhysicsSDK != NULL)
gPhysicsSDK->getFoundationSDK().getRemoteDebugger()->connect("localhost", 5425);

// Set the physics parameters
gPhysicsSDK->setParameter(NX_SKIN_WIDTH, 0.01);

// Set the debug visualization parameters
gPhysicsSDK->setParameter(NX_VISUALIZATION_SCALE, 1);
gPhysicsSDK->setParameter(NX_VISUALIZE_COLLISION_SHAPES, 1);
gPhysicsSDK->setParameter(NX_VISUALIZE_ACTOR_AXES, 1);

// Create the scene
NxSceneDesc sceneDesc;
sceneDesc.simType = NX_SIMULATION_SW;
sceneDesc.gravity = gDefaultGravity;
gScene = gPhysicsSDK->createScene(sceneDesc);
if(!gScene)
{
sceneDesc.simType = NX_SIMULATION_SW;
gScene = gPhysicsSDK->createScene(sceneDesc);
if(!gScene) return;
}


// Create the default material
NxMaterial* defaultMaterial = gScene->getMaterialFromIndex(0);
defaultMaterial->setRestitution(0.5);
defaultMaterial->setStaticFriction(0.5);
defaultMaterial->setDynamicFriction(0.5);

// Create the objects in the scene
groundPlane = CreateGroundPlane();
gSelectedActor = CreateBox();
CreateBox();
CreateSphere();
CreateSphere();
// CreateCapsule();

// Initialize HUD
InitializeHUD();

// Get the current time
UpdateTime();

// Start the first frame of the simulation
if (gScene) StartPhysics();
}

void ReleaseNx()
{
if (gScene)
{
GetPhysicsResults(); // Make sure to fetchResults() before shutting down
gPhysicsSDK->releaseScene(*gScene);
}
if (gPhysicsSDK) gPhysicsSDK->release();
}

void ResetNx()
{
ReleaseNx();
InitNx();
}

void StartPhysics()
{
// Update the time step
gDeltaTime = UpdateTime();

// Start collision and dynamics for delta time since the last frame
gScene->simulate(gDeltaTime);
gScene->flushStream();
}

void GetPhysicsResults()
{
// Get results from gScene->simulate(gDeltaTime)
while (!gScene->fetchResults(NX_RIGID_BODY_FINISHED, false));
}

int main(int argc, char** argv)
{
PrintControls();
InitGlut(argc, argv);
InitNx();
glutMainLoop();
ReleaseNx();
return 0;
}

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So, from what to start....

First of all, I want to ask you: "Did you want to implement something like Nehe's Tutorial #30 using NVIDIA PhysX?".

If yes, then:

Let's create your 'rectangular cuboid'.  In physX you need to create box as convex/triangle mesh (which would be a static object). Get the example code from SDK (let it be as convex mesh):



//Create a box convex mesh.

NxVec3 verts[8] = { NxVec3(-1,-1,-1),NxVec3(-1,-1,1),NxVec3(-1,1,-1),NxVec3(-1,1,1), NxVec3(1,-1,-1),NxVec3(1,-1,1),NxVec3(1,1,-1),NxVec3(1,1,1) };  // with dimensions NxVec3(1,1,1) ... rescale it as you wish.

NxU32 vertCount = 8;

 // Create descriptor for convex mesh

NxConvexMeshDesc convexDesc;

convexDesc.numVertices = vertCount;

convexDesc.pointStrideBytes = sizeof(NxVec3);

convexDesc.points = verts;

convexDesc.flags = NX_CF_COMPUTE_CONVEX;

/*

Here you need to add NX_CF_FLIPNORMALS flag to convexDesc (because normals show in which direction of contact force would be applied)




*/


convexDesc.flags |= NX_CF_FLIPNORMALS;


// See SampleCommonCode\src\Stream.cpp for MemoryWriteBuffer and MemoryReadBuffer.

MemoryWriteBuffer buf; bool status = gCooking->NxCookConvexMesh(convexDesc, buf);

NxConvexMesh *mesh = gPhysicsSDK->createConvexMesh(MemoryReadBuffer(buf.data));

// Now create an instance of the mesh.  

NxConvexShapeDesc convexShapeDesc;

NxActorDesc actorDesc;

convexShapeDesc.meshData = mesh;  

actorDesc.shapes.pushBack(&convexShapeDesc);

actorDesc.body = 0; // Make it static

actorDesc.density = 0.0f; 

NxActor *enviromentBox=gScene->createActor(actorDesc); // Define 'enviromentBox' as global variable.... + place it where you want it






Now, let's modify a renderer:



void RenderActors(bool shadows)
{
// Render all the actors in the scene
NxU32 nbActors = gScene->getNbActors();
NxActor** actors = gScene->getActors();
while (nbActors--)
{
NxActor* actor = *actors++;




if(actor == enviromentBox)

{

 glEnable(GL_CULL_FACE);// do if disabled

 glCullFace(GL_FRONT);// If result is inversed to expected -> GL_BACK

 DrawActor(actor, gSelectedActor, false); 

 glDisable(GL_CULL_FACE);// do if you don't need it to rest of objects (if yes, set culling face to your default value)

 continue;

}


DrawActor(actor, gSelectedActor, false);

// Handle shadows
if (shadows)
{
DrawActorShadow(actor, false);
}
}
}




.................

I think thats all (if I don't missed something).




Best wishes,FXACE.

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So, from what to start....

First of all, I want to ask you: "Did you want to implement something like Nehe's Tutorial #30 using NVIDIA PhysX?".

If yes, then:

Let's create your 'rectangular cuboid'.  In physX you need to create box as convex/triangle mesh (which would be a static object). Get the example code from SDK (let it be as convex mesh):



//Create a box convex mesh.

NxVec3 verts[8] = { NxVec3(-1,-1,-1),NxVec3(-1,-1,1),NxVec3(-1,1,-1),NxVec3(-1,1,1), NxVec3(1,-1,-1),NxVec3(1,-1,1),NxVec3(1,1,-1),NxVec3(1,1,1) };   // with dimensions NxVec3(1,1,1) ... rescale it as you wish.

NxU32 vertCount = 8;

// Create descriptor for convex mesh

NxConvexMeshDesc convexDesc;

convexDesc.numVertices = vertCount;

convexDesc.pointStrideBytes = sizeof(NxVec3);

convexDesc.points = verts;

convexDesc.flags = NX_CF_COMPUTE_CONVEX;

/*

Here you need to add NX_CF_FLIPNORMALS flag to convexDesc (because normals show in which direction of contact force would be applied)


*/

convexDesc.flags |= NX_CF_FLIPNORMALS;

// See SampleCommonCode\src\Stream.cpp for MemoryWriteBuffer and MemoryReadBuffer.

MemoryWriteBuffer buf;  bool status = gCooking->NxCookConvexMesh(convexDesc, buf);

NxConvexMesh *mesh = gPhysicsSDK->createConvexMesh(MemoryReadBuffer(buf.data));

// Now create an instance of the mesh.  

NxConvexShapeDesc convexShapeDesc;

NxActorDesc actorDesc;

convexShapeDesc.meshData = mesh;  

actorDesc.shapes.pushBack(&convexShapeDesc);

actorDesc.body = 0; // Make it static

actorDesc.density = 0.0f;  

NxActor *enviromentBox=gScene->createActor(actorDesc);  // Define 'enviromentBox' as global variable.... + place it where you want it





Now, let's modify a renderer:



void RenderActors(bool shadows)
{
// Render all the actors in the scene
NxU32 nbActors = gScene->getNbActors();
NxActor** actors = gScene->getActors();
while (nbActors--)
{
NxActor* actor = *actors++;



 if(actor == enviromentBox) // now set it as how enviromentBox must be displayed

{

glEnable(GL_CULL_FACE);// do if disabled

glCullFace(GL_FRONT);// If result is inversed to expected -> GL_BACK

DrawActor(actor, gSelectedActor, false);

glDisable(GL_CULL_FACE);// do if you don't need it to rest of objects (if yes, set culling face to your default value)

continue;

}


DrawActor(actor, gSelectedActor, false);

// Handle shadows
if (shadows)
{
DrawActorShadow(actor, false);
}
}
}



.................

I think thats all (if I don't missed something).



Best wishes,FXACE.

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Thanks a lot FXACE for your help. Well all i have done is take your code and put it into a nxactor* function like the following





NxActor* CreateEnvironmentBox()
{
NxVec3 verts[8] = { NxVec3(-1,-1,-1), NxVec3(-1,-1,1), NxVec3(-1,1,-1), NxVec3(-1,1,1),
NxVec3(1,-1,-1), NxVec3(1,-1,1), NxVec3(1,1,-1), NxVec3(1,1,1) }; // with dimensions NxVec3(1,1,1)
//... rescale it as you wish.

NxU32 vertCount = 8;

// Create descriptor for convex mesh

NxConvexMeshDesc convexDesc;

convexDesc.numVertices = vertCount;

convexDesc.pointStrideBytes = sizeof(NxVec3);

convexDesc.points = verts;

convexDesc.flags = NX_CF_COMPUTE_CONVEX;

/*
Here you need to add NX_CF_FLIPNORMALS flag to convexDesc
(because normals show in which direction of contact force would be applied)
*/

convexDesc.flags |= NX_CF_FLIPNORMALS;

// See SampleCommonCode\src\Stream.cpp for MemoryWriteBuffer and MemoryReadBuffer.

MemoryWriteBuffer buf;

static NxCookingInterface *gCooking = NxGetCookingLib(NX_PHYSICS_SDK_VERSION);

gCooking->NxInitCooking(); //Build physical model


bool status = gCooking->NxCookConvexMesh(convexDesc, buf);

NxConvexMesh *mesh = gPhysicsSDK->createConvexMesh(MemoryReadBuffer(buf.data));

// Now create an instance of the mesh.

NxConvexShapeDesc convexShapeDesc;

NxActorDesc actorDesc;

convexShapeDesc.meshData = mesh;

actorDesc.shapes.pushBack(&convexShapeDesc);

actorDesc.body = 0; // Make it static

actorDesc.density = 0.0f;

NxActor *enviromentBox = gScene->createActor(actorDesc); // Define 'enviromentBox' as global variable
//.... + place it where you want it
assert(enviromentBox);
return enviromentBox;
}






bu when i call it in the InitNx() it doesn't seem to do anything. Am i doing anything wrong ???





void InitNx()
{
// Initialize camera parameters
gCameraAspectRatio = 1.0f;
gCameraPos = NxVec3(0,5,-15);
gCameraForward = NxVec3(0,0,1);
gCameraRight = NxVec3(-1,0,0);

// Create the physics SDK
gPhysicsSDK = NxCreatePhysicsSDK(NX_PHYSICS_SDK_VERSION);
if (!gPhysicsSDK) return;
else if(gPhysicsSDK != NULL)
gPhysicsSDK->getFoundationSDK().getRemoteDebugger()->connect("localhost", 5425);

// Set the physics parameters
gPhysicsSDK->setParameter(NX_SKIN_WIDTH, 0.01);

// Set the debug visualization parameters
gPhysicsSDK->setParameter(NX_VISUALIZATION_SCALE, 1);
gPhysicsSDK->setParameter(NX_VISUALIZE_COLLISION_SHAPES, 1);
gPhysicsSDK->setParameter(NX_VISUALIZE_ACTOR_AXES, 1);

// Create the scene
NxSceneDesc sceneDesc;
sceneDesc.simType = NX_SIMULATION_SW;
sceneDesc.gravity = gDefaultGravity;
gScene = gPhysicsSDK->createScene(sceneDesc);
if(!gScene)
{
sceneDesc.simType = NX_SIMULATION_SW;
gScene = gPhysicsSDK->createScene(sceneDesc);
if(!gScene) return;
}


// Create the default material
NxMaterial* defaultMaterial = gScene->getMaterialFromIndex(0);
defaultMaterial->setRestitution(0.5);
defaultMaterial->setStaticFriction(0.5);
defaultMaterial->setDynamicFriction(0.5);

// Create the objects in the scene
groundPlane = CreateGroundPlane();
gSelectedActor = CreateBox();
CreateBox();
CreateEnvironmentBox();


// Initialize HUD
InitializeHUD();

// Get the current time
UpdateTime();

// Start the first frame of the simulation
if (gScene) StartPhysics();
}

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Is 'enviromentalBox' actor showing on VRD (Visual Remote Debugger)? What results from PhysX you have?

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No, it is not showing in the VRD. The result is that when i run the program it crashes although it builds successfully. Let me ask you one more thing. Let's assume that i draw a cube with opengl commands for instance glutSolidCube() how can i then tell to physx to apply force to that object.

Should i have to create

1) Actor Descriptor
2) Body Descriptor
3)Shape Descriptor
4) Set Shape Descriptor (localPose.t, density, globalPose.t ... etc).

for every shape i draw with opengl functions such as glutSolidSphere(), glutSolidCone() ... etc.


Thanks.

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"For instance glutSolidCube":

1. You need to create a box actor which has the same attibutes as glutSolidCube. Now you have it on NxScene.

2. Each actor has transformation matrix you load it to OpenGL:



NxActor *actor; (your box actor object)

NxMat34 pose = actor->getGlobalPose();

float glmat[16]; //4x4 column major matrix for OpenGL.
pose.M.getColumnMajorStride4(&(glmat[0]));
pose.t.get(&(glmat[12]));

//clear the elements we don't need:
glmat[3] = glmat[7] = glmat[11] = 0.0f;
glmat[15] = 1.0f;





glPushMatrix();

glMultMatrix(glmat); // apply box's transformation (keeping current view matrix)

glutSolidCube(...); << here you have

glPopMatrix();






3. To apply force to this object use function which is below (from NVIDIA SDK):



virtual void NxActor::addForce ( const NxVec3force, NxForceMode mode = NX_FORCE, bool wakeup = true) [pure virtual] 

Applies a force (or impulse) defined in the global coordinate frame to the actor.

This will not induce a torque.

NxForceMode determines if the force is to be conventional or impulsive.

The actor must be dynamic.

Sleeping: This call wakes the actor if it is sleeping and the wakeup parameter is true (default).Parameters:[in] force Force/Impulse to apply defined in the global frame. Range: force vector [in] mode The mode to use when applying the force/impulse(see NxForceMode) [in] wakeup Specify if the call should wake up the actor.Platform:
  • PC SW: Yes
  • PPU : Yes
  • PS3 : Yes
  • XB360: Yes







    Should i have to create



    1) Actor Descriptor
    2) Body Descriptor
    3)Shape Descriptor
    4) Set Shape Descriptor (localPose.t, density, globalPose.t ... etc).

    for every shape i draw with opengl functions such as glutSolidSphere(), glutSolidCone() ... etc.


    [/quote]

    1. Each actor of NxScene must be created from its description (there you tell to SDK how to with it)


    2. Body descriptor (NxBodyDesc) required for each dynamic actor.


    3. Each actor must have at least one shape.


    4. Use localPose.t if you want to shift (translate) it in actor's frame. Density used for actor which has compound shapes (to compute: center of mass, moment of inertia...)




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