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I am just looking for a broad answer to this question. I am more curious about the general information rather than the specific. Also, I tried to search for this, but I think it's hard to word it so you get the right question. Anyway:

One common thing I see in a lot of games is multiple animations on the same model.


A character runs, but also raises his arms an shoots.

A character has a walking animation, but can also be carrying resources as he walks.

I am curious if the first model has a "run" animation and a "run while shooting" animation. Or if they have a "run" animation and a "shoot" animation and run them at the same time. Obviously the first is possible, but I am wondering how the second one is done.

Do they use two models for upper and lower body or is there a way to ignore certain parts of a model when animating?

I know this depends a lot on the model, the programmer, language and the way the animation is done.

But broadly, if you were making a model with the intent of it doing multiple animations at once, what would be the best way to go about it?

Again, not after detailed specifics, just an overview :)



marked as duplicate by Anko, Sean Middleditch, Jesse Dorsey Feb 10 '14 at 17:51

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • \$\begingroup\$ You are looking for the term "animation blending." \$\endgroup\$ – Sean Middleditch Feb 9 '14 at 22:23
  • 1
    \$\begingroup\$ Ah, the only form of animation blending I have seen is moving smoothly from one animation to the next, not running two at once. So blending covers both? Or do you mean there are two animations (the run and the run while shooting) and you just blend them when it switches rather than any other method? \$\endgroup\$ – Nexian Feb 9 '14 at 23:53
  • \$\begingroup\$ "animation blend trees" may be a further refinement to search on. Typically, yes, you can have multiple animations running at once (even physics things like ragdolls or IK) and allow artist-controlled weighting between the animations. This is how you do things like have multiple speeds of walk/run animation and transition between them smoothly, as well. \$\endgroup\$ – Sean Middleditch Feb 10 '14 at 0:00
  • \$\begingroup\$ Thanks Sean. This has been very helpful. I'll look through the terms mentioned. Also, thanks for not responding with "google it". I tried, but as you say, if I don't know the terms, I'm not going to turn up much :) \$\endgroup\$ – Nexian Feb 10 '14 at 1:20

Do they use two models for upper and lower body or is there a way to ignore certain parts of a model when animating?

No and yes. No, only one model is used. Yes, there is a way to ignore certain parts of a model. Actually it is quite simple: You don't animate them. And when you have two animations that don't overlap in "parts affected" it is trivial to combine them (i.e. running them at the same time).

Technically the "ignore" part of the animation matrix is the identity matrix and multiplying both animation matrixes produces the desired combined animation.


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