16. The method of claim 15, wherein the decomposition comprises the steps of: selecting a constituent model referenced by the lower-level cell; determining whether the shape model in the selected cell maintains a rain relationship with the constituent model; and determining whether the constituent model is a shape model.
16. The method of claim 15, wherein the decomposition comprises the steps of: selecting a constituent model referenced by the lower-level cell; determining whether the shape model in the selected cell maintains a rain relationship with the constituent model; and determining whether the constituent model is a shape model. 17. The method of claim 16, wherein in the event that shape model in the selected cell does not maintain a rain relationship with the constituent model and the constituent model is a shape model, the method further comprises the step of identifying the constituent model as friendly with the shape model in the selected cell.