Hi. Finally I made my unit work in SWBF2, but I have a small problem now. I did the enveloping like the tutorial said, going to animation>enveloping>set envelope I think it said. I selected all the bones (not the nulls) including, hp_weapons, GroundDummy.bone_pelvis and GroundDummy.bone_root.

I thought all was going well, but when I enter the game, I see my unit, but the enveloping is wrong, because I see the right arm of my unit in a strange form, not like the original units of the game. In this screenshot he has the secondary weapon, the gun:
Also the shoulder is strange, and the legs too. But in Softimage, the unit is in the right place with the bones:

Is there other way to do the enveloping? Or a tip, or something to do this working well?
Thanks.

Your obvious problem is that you have unconnected vertices using alternating bones. It's the same problem you'd see if you enveloped part of a shoulderpad to ribcage/upperarm and then part of the upper arm/shoulder to ribcage/upperarm. There's not an easy or automatic fix. You just need to play around with your weights until you find something that looks good.

Ohhh, that makes sense. I'll fix that. Thanks : )