Hi,
Thought my question fits here.
I am trying to figure out how to construct contact graphs as described in Guendelman et al. (2003) "Nonconvex Rigid Bodies with Stacking".
The basic idea is to group objects into levels, and the ground/immovable objects are at level 0. The rest of objects are placed at level i if they rest on objects at level i-1.
This is easily pictured for a stack of N boxes on a ground plane. The order is just that level starting from 1 for the box directly on the ground, and then level 2 for the next box up, etc. until level N for the box at the top.
However, I am having difficulty in sorting out the order for some complicated configurations, e.g. the one shown in Fig. 7 of Hahn's 1988 paper "Realistic animation of rigid bodies". In this figure, Object A rests on both the immovable wall and B, such that there is directed edge pointing from B to A (of course there is another one from wall/ground to A). I think for this configuration, the wall/ground is at level 0; A, B, D, E are all at level 1; and C is at level 2. Am I correct?
Thanks,
Bin Zhao