How can I use collisions when manualling positioning objects? As an example, say I have a cube and a sphere above it. I have my editor that I can click and drag the sphere to position it. With gravity enabled it falls and bounces off the cube. If I turn off gravity and move the sphere down, it penetrats the cube. It's only when a force is applied that the sphere bounces out/'collides'. Can I do a collision test on move and if so, don't move? How would I structure this in code to perform the collision test?