Hey guys. I need help. I’m trying make my character lose his limbs by shooting or slicing it off. You how Dead space has a lot of death animations for the characters and enemies. I’m trying to do the same thing with blender. Is there a way to do it? Do you have to use shape keys? Key frames? Or modifiers? I’m trying to make a short film with UDK and any help would be appreciated 
Well, I suppose you could have multiple different models, and when a limb is chopped off just replace the original uncut with the cut one and have the limb fall off.
This link would probably help and give ideas, it shows a bit of the workflow for something like this:
Alright thanks bud
And leave us not forget … 'Tis Only A Flesh Wound … 
Seriously, I think I’d approach this using “artful cuts.” (Pun intended, I suppose …) You’ll have several different versions of the model, all based on the same general topology but with different features. (“Bloody left-arm stump,” for example. Ick.) And the rest is basically good-editing, just like you see in the Monty Python clip above.
An “artful cut-away” (uhh, I’ll take that pun also) is usually a good strategy: you don’t actually have to see that “vorpal sword going snicker-snack.” Show the victim, CUT TO the sword comes down from the victim’s point-of-view, CUT TO a shot from the attacker’s point of view and the arm is now cut-off and bleeding (if you like) … and so on until the poor schleb is completely cut to pieces (if you like). Shot-to-shot, you’re changing models. The viewer will (ugh …) “get the idea just fine, thank you.” These are very standard cinematographic tricks and “explicit gore” won’t improve them. (It’ll just waste your time trying.)
If it were me, I’d probably create several models … of both the person and the various appendages … all based upon the same reference model and strictly determined by what you decide is needed, shot by shot, for the entire sequence.
Yeah, that’s generally how it’s done for big productions. Big summer blockbuster exploding robot movies tend to use anywhere from 10 to 100 different completely separate versions of any given robot character at various levels of kaboom. Same goes for monsters and whatnot.
I would love to see somebody make an animation where they cut something and it shows gore. But ill do what you guys suggest and keep it simple so to speak.