If an object is moving across the screen, such as a warthog driving by, then wouldn't the position data between the front of the hog in one frame and the back of the hog in the next be almost the same? The only major change would come from the front and back of the hog where it's compared with the background. I'm not sure how you would pull objects out of the scene. On the plus side, that new SSDO method works using depth and position data doesn't it?