How to define multiple 3D Connection References?

[8565Technicbots]

In my mechanism below I want to simulate the bouncing shown in example provided in the exercise eleven of the How to Model Anything. The yellow man consistently goes straight through the green box rather than stopping at the bottom of the bin. I tconcluded that it is due to the fact that I do not have all the surfaces referenced as is done in the 4th picture below. How do i do multiple 3D connection references, as I only have one surface 3D connection reference as it does not seem to be enough information for the software to simulate at this point.