yes, I've seen it's not thread safe, and I'm still not sure it relates to a threads problem. The thing is that I always initialize the world and then execute the onDraw (render when dirty) so it shouldn't be directly related to threads... that's why knowing what that line does might help.
Note that the draw is always performed after world manipulation (ticking loop ends with redraw), so no thread problem here (and I've even synchronized the tick/draw blocks, just in case). And, as I said, starting the ticking/drawing at a different spot does work as usual (that's why I suspected a link to onTouchEvent/other thread).

Hi,

I'm getting a Null pointer in World class, line 1021, but only when I setup the world contents at certain point in the code. Might be about the different threads (i.e. onCreate works, onTouchEvent fails) but there might be something else going on, I still can't find the reason. It might help to know what's happening at that line in class World (I think it's version 1.22, downloaded about a month ago).
Here's the exception...
E/AndroidRuntime(14758): FATAL EXCEPTION: GLThread 8
E/AndroidRuntime(14758): java.lang.NullPointerException
E/AndroidRuntime(14758):        at com.threed.jpct.World.renderScene(World.java:1021)
E/AndroidRuntime(14758):        at com.loxai.run.GameRenderer.onDrawFrame(GameRenderer.java:104)
E/AndroidRuntime(14758):        at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1332)
E/AndroidRuntime(14758):        at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1116)

... so, what's the world like in 1021?

Ok, solved... the second (preferred) alternative works. It's just that I wasn't setting the collision mode to SELF (only OTHERS). Still not sure about the use of the axis vectors...
Hi, this is my second post, and it's about time to thank the developers on their effort to create an easy and comfortable 3D engine. After a project directly working with opengl (Trapped, for Android), this is a welcomed change.
That said, my 3d math knowledge is quite limited and conflicting with implementation of collisions. I am working on a top down view game with NPCs trying to catch the main character. Now I want to have the NPCs avoid each other (i.e. no overlapping) when stalking the player.
I first tried without checking the corresponding examples, sending to checkForCollisionSpherical() the transformation that I would send to translate() (thinking the collision would be based on the transformed position, but also trying to add the current transformed position). Seeing that wouldn't work I checked the wiki and I see the use of getX/Z/YAxis() which I don't quite understand, still tried to implement it, obviously with no success... here's the alternatives I have tried:
       if (false){
            SimpleVector center = getTransformedCenter();
            SimpleVector t = new SimpleVector(speedX + center.x, speedY + center.y, center.z);
            SimpleVector avoid = checkForCollisionSpherical(t, 5f);
            if (avoid.equals(t))
                translate(speedX, speedY, 0);
        }
        if (false){
            SimpleVector avoid = checkForCollisionSpherical(new SimpleVector(speedX, speedY, 0), 5f);
            translate(avoid);
        }
        if (true){
            //SimpleVector move = new SimpleVector();//getTransformedCenter();
            SimpleVector t = getXAxis();
            t.scalarMul(speedX);
            move.add(t);
            t = getYAxis();
            t.scalarMul(speedY);
            move.add(t);
            move.z = 0;
//System.out.println(t);

            move = checkForCollisionSpherical(move, 5f);
            translate(move);
        }
any hints/links/explanations on how this works would be appreciated...