Skin Modifier
The skin modifier is the more modern form of binding a mesh to a bone structure (in this case a biped), as it has been updated on numerous occasions throughout 3D Studio Max’s version history. Skin is more abstract, more low level and might take more time to set up. However, if you are willing to spend the time it can do exactly what you want.”.
Skin is possibly the best choice for very complex meshes such as a high polygon character for film. Initially similar to physique, envelopes are adjusted at the start of the influence process; this gives a rough setup of what vertexes are affected by what bone. After this is done, it is very precise allowing vertex assignments to be altered in a table. Every vertex’s influence is adjusted by typing in the value for the corresponding vertex, i.e. 1.000 for total influence (rigid) or 0.000 for no influence at all. This can be very time consuming on complex models, but usually results in very good deformation quality (provided the edge flow of the mesh is of a high standard).
To speed the process the vertex weights can be mirrored on symmetrical characters/objects, which was especially useful for this animation as it effectively reduces weighting time by half.
Above is an example of using the Skin modifier on two biped characters.