ODE test

Engines, Libraries and Tools Xith3D Forums
#1

Hi again.

Now i have implemented ODE into my game, but I have a problem:

I have a TransformGroup class called ‘Object3D’,
a ODE collision detection class called ‘CollisionDetection’
and a Xith3D class called ‘World3D’.

I add some Shape3D’s to the Object3D and add it to my World3D, and then I am calling a method in CollisionDetection addObject3D(Object3D),
using OdejavaToXith3D.addUserTransformGroup().

Here’s the problem:


public Body convertToBody(Object3D poObject3D) {
        Body oBody = new Body(poObject3D.getName(), getWorld());
        addNodeRecursive(poObject3D, oBody, poObject3D);
        return oBody;
    }
    
    public void addNodeRecursive(Node poNode, Body poBody, Object3D poObject3D) {
        if (poNode instanceof Group) {
            for (Enumeration oEnumeration = ((Group)poNode).getAllChildren(); oEnumeration.hasMoreElements();) {
                addNodeRecursive((Node)oEnumeration.nextElement(), poBody, poObject3D);
            }
        } else if (poNode instanceof Shape3D) {
            Shape3D oShape3D = (Shape3D)poNode;
            System.out.println(poNode.getUserData());
            IndexedTriangleArray oIndexedTriangleArray = (IndexedTriangleArray)oShape3D.getGeometry();
            GeomTriMesh oGeomTriMesh = Xith3DToOdejava.createTriMesh(oIndexedTriangleArray);
            moMapToObject3D.put(new Integer(oGeomTriMesh.getNativeAddr()), poObject3D);
        }
    }

Like you see the code isn’t completed yet,
because I do not know how to do a Shape3D into a Geom, then adding all Geoms into a Body…

Note: I do not want to make every Shape3D using a IndexedTriangleArray…

Then I am doing in my update method:


        getJavaCollision().collide(getSpace());
        iterateContacts();
        getJavaCollision().applyContacts();

This is my goal:

I want iterateContacts() to call Object3D if any collision occured. (collideWith(Object3D object3D, Tuple3f collisionPoint))

Does anyone have any ideas?

Thanks,
Alonzo

#2

Only use Tri-Mesh if you have a real need, e.g. for terrain.

The most efficient option is to aproximate your 3D display objects with primitive geoms in Xith3d. i.e. my tank collision consists of three simple boxes. This gives very fast collision but still quite realistic.

Look at the org.odejava.display package - you can “bind” ODE Placeable objects (e.g. GeomBox) to Xith3d transform groups.

Will.

#3

Ok I can try :).
But I’m using 3ds so I like to have it in ode, so if anyone know how to do that please reply.

Thanks,
Alonzo