Displaying Newton's ConvexHull in Irrlicht

[Auradrummer]

Hello guys,

I suffered with a code here, and I think that is very useful for those who is using Irrlicht together with Newton Dynamics physics engine. This code allows you to pass a ConvexHull object to Irrlicht and see it without need to initialize any graphics interface by Newton. This way we keep Irrlicht for all graphics.

Code: Select all

ISceneNode* renderConvexHull(NewtonCollision* convexHull, video::SColor color, ISceneManager* smgr)
{
	NewtonMesh* mesh;
	SMesh* irrMesh;
	SMeshBuffer* buffer;
	dInt32 m_vertexCount;
	dInt32 m_indexCount;
	GLfloat *m_uv;
	GLfloat *m_vertex;
	GLfloat *m_normal;
	GLushort* m_indexes;
	int i = 0;
	int x = 0;
	int handle;
	
	mesh = NewtonMeshCreateFromCollision(convexHull);

	// getting vertexes position

  	m_vertexCount = NewtonMeshGetVertexCount (mesh);
	
	m_vertex = (GLfloat*) malloc (3 * m_vertexCount * sizeof (GLfloat)); 
	m_normal = (GLfloat*) malloc (3 * m_vertexCount * sizeof (GLfloat)); 
	m_uv = (GLfloat*) malloc (2 * m_vertexCount * sizeof (GLfloat)); 
	memset (m_uv, 0, 2 * m_vertexCount * sizeof (GLfloat));
		
	NewtonMeshGetVertexStreams (mesh,
		3 * sizeof (GLfloat), (dFloat*) m_vertex,
		3 * sizeof (GLfloat), (dFloat*) m_normal,
		2 * sizeof (GLfloat), (dFloat*) m_uv);

	// Getting face indexes.

	handle = NewtonMeshFirstMaterial(mesh);
	
	m_indexes = (GLushort *) malloc (m_indexCount * sizeof (GLushort )); 
	m_indexCount = NewtonMeshMaterialGetIndexCount (mesh, handle);
	
	NewtonMeshMaterialGetIndexStreamShort (mesh, handle, (short int*)m_indexes);

	// Creating SMesh
	
	buffer = new SMeshBuffer();

   	buffer->Indices.set_used(m_indexCount);
   	for (i=0; i<m_indexCount; ++i)
		buffer->Indices[i] = m_indexes[i];
	
	buffer->Vertices.set_used(m_vertexCount);
	for (i=0; i < m_vertexCount * 3; i+=3)
	{  
		buffer->Vertices[x]  = video::S3DVertex(m_vertex[i], m_vertex[i+1], m_vertex[i+2],1,1,1,color, 1, 1);
		x++;
	}
  	
  	irrMesh = new SMesh();
   	irrMesh->addMeshBuffer(buffer);

   	ISceneNode * collmesh = smgr->addMeshSceneNode(irrMesh);
	collmesh -> setMaterialFlag(EMF_LIGHTING,false);
	collmesh -> setMaterialFlag(EMF_WIREFRAME, true);

	NewtonMeshDestroy(mesh);
	return (collmesh);
}

That's it, I think this can be useful for more people !

[agi_shi]

Useful indeed, but only available in Newton Archimedia (not 1.53).

[sudi]

there is a better way to do this.
just use the dofor allbodies command and then draw lines for each newton object.

[agi_shi]

there is a better way to do this.
just use the dofor allbodies command and then draw lines for each newton object.

Not necessarily. The above code creates an actual mesh from a Newton collision object. Your suggestion doesn't create a mesh, it only draws a wireframe over-view.

[Halifax]

there is a better way to do this.
just use the dofor allbodies command and then draw lines for each newton object.

Not necessarily. The above code creates an actual mesh from a Newton collision object. Your suggestion doesn't create a mesh, it only draws a wireframe over-view.

It would appear that Auradrummer wants to see a ConvexHull object without the need to initialize the graphics interface Newton has.

This code allows you to pass a ConvexHull object to Irrlicht and see it without need to initialize any graphics interface by Newton.

I fail to see how wireframe wouldn't suffice, and also this method creates a second copy of the data basically just for use with Irrlicht. So really this is a waste of memory, and a waste of a scene node.

A wireframe overview doesn't suffer from any of these problems, and seeing as it's probably only used for debugging purposes, then I don't see speed entering into the equation.