I want to use camera tracking in blender to create the effect of an object(let's call it a 'ghost') sitting in the middle of a road. I want to be able to let objects pass by in front of the 'ghost' and hide it from the view of the camera, and than have it shown again, like a car driving by in-front of it. Is there a way to do all of this in blender? A way to only do part of it, and the rest in another program? Or will I need to use a separate program all together to do it?