First of all, thanks to all contributors for the excellent fully managed physics API… you all rock. Now on to the question(s):
1) I have a CollisionSystemGrid, a HeightMap and many boxes and spheres. The boxes and spheres always collide with the height map, but depending on where I add them, they sometimes don't collide with each other. It seems that my grid entries do not encompass the whole height map, and when I add objects in an area with no grid entries, the objects fail to collide with each other. I haven't attempted to debug it, but it seems like a bug, because I would expect these objects to get added to an overflow and still collide with each other.
2) When I add my HeightMap to the CollisionSystemGrid, I get the message "CollisionSkin too big for gridding system - putting it into overflow list". I assume this is fine because it happens in JigLibGame. But it got me thinking, would my performance improve if I split the HeightMap up into grid sized segments and added them individually? I will probably need to this for LODding anyway, but am I likely to get any physics performance boost?