Merci, maintenant, il n'y a aucun bug, cube1 "tombe", mais passe a travers cube2. Pourquoi?

Voici mon code actuel:

#include <cstdlib>
#include <iostream>
#include <IRR/irrlicht.h>

#include <Newton/Newton.h>

using namespace std;

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

void _cdecl ApplyForceAndTorqueEvent (const NewtonBody* body,float timestep, int threadindex)
{
   float mass;
   float Ixx;
   float Iyy;
   float Izz;
   float force[3];
   float torque[3];

   NewtonBodyGetMassMatrix (body, &mass, &Ixx, &Iyy, &Izz);

   force[0] = 0.0f;
   force[1] = -9.81 * mass;
   force[2] = 0.0f;

   torque[0] = 0.0f;
   torque[1] = 0.0f;
   torque[2] = 0.0f;

   NewtonBodyAddForce (body, force);
   NewtonBodyAddTorque (body, torque);
}

int main(int argc, char **argv)
{
// Initialisation Newtoniénne  // ---------------------------------------------------------
NewtonWorld*world = NewtonCreate(0,0);

// Initialisation Irrlichiénne // ---------------------------------------------------------
IrrlichtDevice *irrDev = createDevice (EDT_OPENGL, dimension2d<s32>(800,600), 32, false, true, false, 0);
IVideoDriver* driver = irrDev->getVideoDriver ();
ISceneManager *scene = irrDev->getSceneManager ();
scene->addCameraSceneNode (0, core::vector3df (0,0,0), core::vector3df (5,0,0));

// Creation d'une lumiere ambiente // ----------------------------------------
driver->setAmbientLight(video::SColorf(1.0, 1.0, 1.0,0.0));

// Creation d'une camera FPS // ----------------------------------------------
ICameraSceneNode *camera = scene->addCameraSceneNodeFPS (0,100,10);
camera->setPosition(vector3df(0,1,-5));


// Créer le corp1 // ------------------
		NewtonBody*body1 ;
		// On Initialise le corp1 // ----------
		NewtonCollision* colision=  NewtonCreateBox(world,1000,1000,1000,0,0);
		body1 = NewtonCreateBody(world,colision) ;
		 NewtonBodySetCollision(body1, colision);
                NewtonReleaseCollision (world, colision);
		// On lui assigne une matrice // -----
		core::matrix4 mat1 ;
		mat1.setTranslation(core::vector3df(0.52,3,0));
		NewtonBodySetMatrix(body1,mat1.pointer());
		// Configurer la mass et l'inertie //-
		NewtonBodySetMassMatrix(body1,20,2,2,2);
		// Force de gravité // -----------------
		NewtonBodySetForceAndTorqueCallback(body1, ApplyForceAndTorqueEvent);
		// Initialisation Irr pour le cube1 // --------
		scene::ISceneNode*cube1 = smgr->addCubeSceneNode(10);
		cube1->setMaterialTexture(0, driver->getTexture("metal.jpg"));
         

					// Créer le corp2 // ------------------
			NewtonBody*body2 ;
			// On Initialise le corp2 // ----------
			NewtonCollision* colision2=  NewtonCreateBox(world,1000,1000,1000,0,0);
			body2 = NewtonCreateBody(world,colision2);
			NewtonBodySetCollision(body2, colision2);
                        NewtonReleaseCollision (world, colision2);
			// On lui assigne une matrice // -----
			core::matrix4 mat2 ;
			NewtonBodySetMatrix(body2,mat2.pointer());
			// Configurer la mass et l'inertie //-
			NewtonBodySetMassMatrix(body2,0,0,0,0);
			// Initialisation Irr pour le cube2 // --------
			scene::ISceneNode *cube2 = smgr->addCubeSceneNode(10);
			cube2->setMaterialTexture(0, driver->getTexture("carrelage.jpg"));


// La boucle principale du rendu // -----------------------------------------
while (irrDev->run ())
      {
        NewtonBodyGetMatrix(body1,&mat1.M[0]);
        cube1->setRotation(mat1.getRotationDegrees());
        cube1->setPosition(mat1.getTranslation());
       
        NewtonBodyGetMatrix(body2,&mat2.M[0]);
        cube2->setRotation(mat2.getRotationDegrees());
        cube2->setPosition(mat2.getTranslation());
       
        NewtonUpdate ( world, 1 / 60 ) ;

        //On indique qu'on démarre la scène
        driver->beginScene (true, true, video::SColor (255,255,255,255));
        scene->drawAll ();
        driver->endScene ();
    }
return 0 ;
}