TheWiseEyes lied about that; his mod was hopeless. Moving solids would actually be quite menial to do, but would require time to get right. Also the lag produced by collision and rotation algorithms would cause them to be redundant. If someone wants to try however; make an element with the state set to none and velocities etc at 0, so you have to cause manual movement. In the update script assign a single element as the controller; and store an array of other 'objects' in the solid. The objects will be zombies; completely useless and dormant. Their brain is the control particle. Using trigonometry you should be able to correctly do rotation and collision bounces. For collision with other particles - the movement code would have to be modified.