Here are two screenies with some numbered steps below:
https://img835.imageshack.us/img835/710/bones1n.jpg
- On the modifier panel, click add bones
- From the selection window, add the bones you wish to add
- The bones should appear on your active bones for that modifier now, here you can select which bone should be active for editing.
- From the quad menu, select envelope to edit the envelopes for the currentyl selected bone link
By default, 3d studio does a pretty good job with estimating the envelopes for the skeleton. With minimum modification to these envelopes you can have a very good starting point. You can edit the envelopes by simply dragging them in your viewport, or changing the different fallof values in the modifier panel.
https://img692.imageshack.us/img692/1659/bones2.jpg
To edit specific bone weight on vertices, select a bone link, and make sure you are in the envelope mode (otherwise you won’t see the results).
- click on paint weights
- click on the … next to paint weights
- this should bring up the brush settings panel that lets you specify various settings of your vertex paint brush
- in viewport, paint the weight for the vertices associated to your currently active bone. Warm color represents bigger weight, cold colors less.
It took me a while to get the ‘feel’ of the brush, so at first you might want to just experiment with the envelopes, or look up some online tutorials. Once you get the hang of it, it’s really easy tho.