public void createCollisionData() {
        BIHTree tree = new BIHTree(this);
        tree.construct();
        collisionTree = tree;
    }
Generates a collision tree for the mesh.
Called automatically by {@link #collideWith(com.jme3.collision.Collidable,
com.jme3.math.Matrix4f,
com.jme3.bounding.BoundingVolume,
com.jme3.collision.CollisionResults) }.
jme3-core/src/main/java/com/jme3/scene/Mesh.java