@kagazwala said:

Chri

Sorry for being a nerd, but I really didnt get what you trying to explain

%(#0000FF)[hi kagazwala

Have you try my example kagazwala 3 with sketchyphysics ?

Take a look on the next vidéo.

concept
when two parts are common parts, they repel
i think it's the major probleme of your scene .

take a look and test my example kagazwala 4 with sketchyphysics

chri]

kagazwala 3.avi

kagazwala 4.skp

kagazwala 4.png

example of concave part.png