Problem with Newton and irrlicht[SOLVED]

[petra999]

Hello!

I tried to do something with irrlicht and newton.
I do some easy program with this->http://gpwiki.org/index.php/Irrlicht:Physics tutorial.

But i have done something bad, and nothing happend(no gravity, etc), what i do wrong?
I do you know some nice tutorials to newton, and newton with irrlicht?

Thanks a lot for any reply.

petra999

And source code:

Code: Select all

#include <Irrlicht.h>
#pragma comment(lib, "Irrlicht.lib")
#include <newton.h>
#pragma comment(lib, "Newton.h")

using namespace irr;
using namespace video;
using namespace core;
using namespace scene;
unsigned int lasttick;



int main()
{
    NewtonWorld* nWorld = NewtonCreate(NULL, NULL);
    NewtonBody* nCube = 0;
    NewtonCollision* collision = NewtonCreateBox(nWorld, 0, 0, 0, NULL);
    nCube = NewtonCreateBody(nWorld, collision);
    NewtonReleaseCollision(nWorld, collision);


	IrrlichtDevice* device = createDevice(EDT_OPENGL, dimension2d<s32>(1000, 680), 16,	false, false, false, 0);

	IVideoDriver* driver = device->getVideoDriver();
	ISceneManager* smgr = device->getSceneManager();

	ISceneNode* cube = smgr->addCubeSceneNode();
    cube->setPosition(vector3df(0,1110,50));
	cube->setMaterialFlag(EMF_LIGHTING, false);
	cube->setMaterialTexture( 0, driver->getTexture("C:/irrlicht-1.4.1/media/irrlichtlogo.jpg"));

    NewtonBodySetUserData(nCube, cube);
    NewtonBodySetMassMatrix(nCube, 1000, 10, 10, 10);
    matrix4 mat;
    mat.setTranslation(vector3df(0, 1110, 50));
    NewtonBodySetMatrix(nCube, &mat.M[0]);
    float omega[3] = {1, 2, 1};
    NewtonBodySetOmega(nCube, &omega[0]);


	ISceneNode* cube1 = smgr->addCubeSceneNode();
    cube1->setPosition(vector3df(0,1125,50));
	cube1->setMaterialFlag(EMF_LIGHTING, false);
	cube1->setMaterialTexture( 0, driver->getTexture("C:/irrlicht-1.4.1/media/dirlogo.jpg"));


    ISceneNode* podloga = smgr->addCubeSceneNode();
    podloga->setScale(vector3df(1000, 1, 1000));
	podloga->setMaterialFlag(EMF_LIGHTING, false);
	podloga->setMaterialTexture( 0, driver->getTexture("C:/irrlicht-1.4.1/media/wall.jpg"));

	ICameraSceneNode* cam = smgr->addCameraSceneNodeFPS();
	cam->setPosition(vector3df(50, 1110, 50));
    smgr->addSkyDomeSceneNode(driver->getTexture("C:/irrlicht-1.4.1/media/irrlicht2_bk.jpg"),16,16,1.3f,2.0f);
    cam->setFarValue(90000);
    cam->setTarget(cube->getPosition());


	while (device->run())
	{
		if (device->isWindowActive())
		{
			driver->beginScene(true, true, SColor(255,255,255,255));

			smgr->drawAll();
            //cam->setTarget(cube->getPosition());
            	if (device->getTimer()->getTime() > lasttick + 10)
            	{
                    lasttick = device->getTimer()->getTime();
                    NewtonUpdate(nWorld, 0.01f);
                }

            float matrix[4][4];
            NewtonBodyGetMatrix(nCube, &matrix[0][0]);
            matrix4 mat;
            memcpy(mat.M, matrix, sizeof(float)*16);
            cube->setPosition(mat.getTranslation());
            cube->setRotation(mat.getRotationDegrees());

			driver->endScene();
		}
	}

	device->drop();
	NewtonDestroy(nWorld);

	return 0;
}

[B@z]

hi!
i'm not using newton now, but if i remember correctly, there was a problem with the world's size.
if the model is out of the world's bounding box, it freezes, isn't effected by gravity.

i don't remember well, but maybe this makes sense

[petra999]

you've got right. i change:

Code: Select all

    NewtonCollision* collision = NewtonCreateBox(nWorld, 0, 0, 0, NULL); 

to

Code: Select all

    NewtonCollision* collision = NewtonCreateBox(nWorld, 10000, 10000, 10000, NULL); 

Now my cube is rotating nice.
But why rotating? why not falling down?

Do you know some nice tutorial?

THANKS A LOT!!!!

[B@z]

sorry, i don't remember how to use it xD

i used this source:

http://newtondynamics.com/downloads/MerciorDemo.zip

[B@z]

i played with newton a lot, but i droped it xD i realized that i don't need it.
but i give the code what i made.
it's messy a lot, but maybe you can get something.

http://web.t-online.hu/andreas101/Newt.rar

[petra999]

thanks!

[matibee]

You have to add a callback function to your body in which you'll add gravity yourself. There's no concept of gravity explicitly built into Newton - it's just another force acting on a body.

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matrix4  g_matPos;

void BodyForceCB (const NewtonBody* body)
{
  _vec3f vGravity( 0.0f, -9.8f, 0.0f );

  float mass, Ixx, Iyy, Izz;

  // get the mass of the object
  NewtonBodyGetMassMatrix (body, &mass, &Ixx, &Iyy, &Izz);

  // keep the objects postion for rendering	 
  NewtonBodyGetMatrix( body, (float *)&g_matPos[0] );

  // calculate the force on the object
  _vec3f vForce = vGravity * mass;
  NewtonBodySetForce (body, (float *)&vForce );
}

In this function you can;
add other forces to the body
user the (void *) user data of the body to access a particular instance of a body (this func could be used on all bodies this way and you don't need different callbacks for every body)

In your set up code, add this callback to your body

Code: Select all

NewtonBodySetForceAndTorqueCallback( nCube, BodyForceCB );

And why is your collision cudbe 10000 units square??? It's too big for Newton to handle well. Is the cube model really this big?

Cheers
Matt

[petra999]

now is working, thanks!