Hello all,

I am trying to get this code to work. It builds fine, but when running it I get exception thrown: 0x001B656F in IrrBullet.exe: 0xC0000005: Access violation reading location 0x0000001C. Then I get Unhandled exception at 0x001B656F in IrrBullet.exe: 0xC0000005: Access violation reading location 0x0000001C.

I am using C++ and Irrlicht 3D engine and Bullet physics. I have posted the code from where the exception is thrown. I can post more code if it is needed.

	u32 TimeStamp = Timer->getTime(), DeltaTime = 0; //update time and physics
	while (!Done)
	{
		DeltaTime = Timer->getTime() - TimeStamp;
		TimeStamp = Timer->getTime();

		UpdatePhysics(DeltaTime);
	}

static void UpdatePhysics(u32 TDeltaTime)
{
	World->stepSimulation(TDeltaTime * 0.001f, 60); //exception comes for this line

	for (list<btRigidBody*>::Iterator it = Bodies.begin(); it != Bodies.end(); ++it)
	{
		UpdateGraphics(*it);
	}
}

fleabay said:

u32 is an unsigned int. You need floating point.

I still get the same error after changing it to f32.

Other than what fleabay pointed out, the code you posted seems ok. But the problem is probably elsewhere.

Step through the code with a debugger and figure out where the code is doing something you don't expect.

Well I tried running through it with a debugger, but it still stops at the stepsimulation function. I can post all my code and see if maybe I'm doing something that is getting overlooked.

#include <iostream>

#include <irrlicht.h>
#include <btBulletDynamicsCommon.h>
#include <btBulletCollisionCommon.h>

using namespace std;

using namespace irr;
using namespace core;
using namespace scene;
using namespace video;
using namespace io;
using namespace gui;

static void CreateInitialScene();
static void CreateGround(const btVector3& TPosition, const vector3df& TScale, btScalar TMass);
static void CreateBox(const btVector3& TPosition, const vector3df& TScale, btScalar TMass);
static void CreateBall(const btVector3& TPosition, btScalar TRadius, btScalar TMass);
static void UpdatePhysics(f32 TDeltaTime);
static void UpdateGraphics(btRigidBody* TBodies);
static void ClearBodies();

static int GetRandInt(int TMax) { return rand() % TMax; }

static bool Done = false;
static btDiscreteDynamicsWorld* World;
IrrlichtDevice* Device;
IVideoDriver* Driver;
ISceneManager* Smgr;
IGUIEnvironment* Env;
IFileSystem* File;
ITimer* Timer;
ILogger* Log;

list <btRigidBody*> Bodies;

class MainEvent : public IEventReceiver {

public:

	virtual bool OnEvent(const SEvent &TEvent) {

		if (TEvent.EventType == EET_KEY_INPUT_EVENT && !TEvent.KeyInput.PressedDown) {
			switch (TEvent.KeyInput.Key) {
			case KEY_ESCAPE:
				Done = true;
				break;
			case KEY_KEY_1:
				CreateBox(btVector3(GetRandInt(10) - 5.0f, 7.0f, GetRandInt(10) - 5.0f), vector3df(GetRandInt(3) + 0.5f, GetRandInt(3) + 0.5f, GetRandInt(3) + 0.5f), 1.0f);
				break;
			case KEY_KEY_2:
				CreateBall(btVector3(GetRandInt(10) - 5.0f, 7.0f, GetRandInt(10) - 5.0f), GetRandInt(5) / 5.0f + 0.2f, 1.0f);
				break;
			case KEY_KEY_X:
				CreateInitialScene();
				break;
			default:
				return false;
				break;
			}

			return true;
		}

		return false;
	}
};

int main(int argc, char* argv[])
{
	MainEvent receiver;

	Device = createDevice(EDT_OPENGL, dimension2d<u32>(1024, 720), 32, false, false, false, &receiver);
	Env = Device->getGUIEnvironment();
	Timer = Device->getTimer();
	Smgr = Device->getSceneManager();
	Driver = Device->getVideoDriver();

	btDefaultCollisionConfiguration* collisionCong = new btDefaultCollisionConfiguration();
	btBroadphaseInterface* broadphase = new bt32BitAxisSweep3(btVector3(-1000, -1000, -1000), btVector3(1000, 1000, 1000));
	btCollisionDispatcher* dispatcher = new btCollisionDispatcher(collisionCong);
	btSequentialImpulseConstraintSolver* solver = new btSequentialImpulseConstraintSolver();
	World = new btDiscreteDynamicsWorld(dispatcher, broadphase, solver, collisionCong);

	ICameraSceneNode* Cam = Smgr->addCameraSceneNode();
	Cam->setPosition(vector3df(0.0f, 5.0f, -15.0f));
	Cam->setTarget(vector3df(0, 0, 0));

	Smgr->addLightSceneNode(0, vector3df(2, 5, -2), SColorf(4, 4, 4, 1));
	CreateInitialScene();

	f32 TimeStamp = Timer->getTime(), DeltaTime = 0;
	while (!Done)
	{
		DeltaTime = Timer->getTime() - TimeStamp;
		TimeStamp = Timer->getTime();

		UpdatePhysics(DeltaTime);

		Driver->beginScene(true, true, SColor(255, 20, 0, 0));
		Smgr->drawAll();
		Env->drawAll();
		Driver->endScene();
		Device->run();
	}

	ClearBodies();

	delete World;
	delete solver;
	delete dispatcher;
	delete broadphase;
	delete collisionCong;

	Device->drop();

	return 0;
}

static void UpdatePhysics(f32 TDeltaTime)
{
	World->stepSimulation(TDeltaTime * 0.001f, 60);

	for (list<btRigidBody*>::Iterator it = Bodies.begin(); it != Bodies.end(); ++it)
	{
		UpdateGraphics(*it);
	}
}

static void CreateInitialScene()
{
	ClearBodies();
	CreateBox(btVector3(0.0f, 0.0f, 0.0f), vector3df(10.0f, 0.5f, 10.0f), 0.0f);
}

static void CreateGround(const btVector3& TPosition, const vector3df& TScale, btScalar TMass)
{

}

static void CreateBox(const btVector3& TPosition, const vector3df& TScale, btScalar TMass)
{
	ISceneNode* Node = Smgr->addCubeSceneNode(1.0f);
	Node->setScale(TScale);
	Node->setMaterialFlag(EMF_LIGHTING, 1);
	Node->setMaterialFlag(EMF_NORMALIZE_NORMALS, true);

	btTransform Transform;
	Transform.setIdentity();
	Transform.setOrigin(TPosition);

	btDefaultMotionState* Motion = new btDefaultMotionState(Transform);

	btVector3 HalfExtents(TScale.X * 0.5f, TScale.Y * 0.5f, TScale.Z * 0.5f);
	btCollisionShape* Shape = new btBoxShape(HalfExtents);

	btVector3 LocalInertia;
	Shape->calculateLocalInertia(TMass, LocalInertia);

	btRigidBody* Body = new btRigidBody(TMass, Motion, Shape, LocalInertia);

	Body->setUserPointer((void*)(Node));

	World->addRigidBody(Body);
	Bodies.push_back(Body);
}

static void CreateBall(const btVector3& TPosition, btScalar TRadius, btScalar TMass)
{

}

static void UpdateGraphics(btRigidBody* TBodies)
{
	ISceneNode* Node = static_cast<ISceneNode*>(TBodies->getUserPointer());

	btVector3 Point = TBodies->getCenterOfMassPosition();
	Node->setPosition(vector3df((f32)Point[0], (f32)Point[1], (f32)Point[2]));

	vector3df Euler;
	const btQuaternion& TQuat = TBodies->getOrientation();
	quaternion q(TQuat.getX(), TQuat.getY(), TQuat.getZ(), TQuat.getW());
	q.toEuler(Euler);
	Euler *= RADTODEG;
	Node->setRotation(Euler);
}

static void ClearBodies()
{
	for (list<btRigidBody *>::Iterator It = Bodies.begin(); It != Bodies.end(); ++It) {
		btRigidBody *Object = *It;

		// Delete irrlicht node
		ISceneNode *Node = static_cast<ISceneNode *>(Object->getUserPointer());
		Node->remove();

		// Remove the object from the world
		World->removeRigidBody(Object);

		// Free memory
		delete Object->getMotionState();
		delete Object->getCollisionShape();
		delete Object;
	}

	Bodies.clear();
}

fleabay said:

http://forums.codeblocks.org/index.php?topic=18318.0

If you think you're going to cut and paste your way into becoming a programmer (from square one no doubt) then You've Got Another Thing Coming. Not AC/DC but close enough.

Yes I am using a tutorial to help me figure out how to use Bullet with Irrlicht. I did change a couple things. This was just to help me get going then modify it as I got it working.

EDIT: Ok After running it through the debugger, I'm getting that the “World” variable is 0x00000 NULL.