@Override
    public int collideWith(Collidable other, CollisionResults results) {
        // Force bound to update
        checkDoBoundUpdate();
        // Update transform, and compute cached world matrix
        computeWorldMatrix();

        assert (refreshFlags & (RF_BOUND | RF_TRANSFORM)) == 0;

        if (mesh != null) {
            // NOTE: BIHTree in mesh already checks collision with the
            // mesh's bound
            int prevSize = results.size();
            int added = mesh.collideWith(other, cachedWorldMat, worldBound, results);
            int newSize = results.size();
            for (int i = prevSize; i < newSize; i++) {
                results.getCollisionDirect(i).setGeometry(this);
            }
            return added;
        }
        return 0;
    }
Sets the model bound to use for this geometry.
This alters the bound used on the mesh as well via
{@link Mesh#setBound(com.jme3.bounding.BoundingVolume) } and
forces the world bounding volume to be recomputed.

@param modelBound The model bound to set
jme3-core/src/main/java/com/jme3/scene/Geometry.java