Non-destructive secondary motion animation - how?

I have a core animation done. Now I want to add secondary motion without destroying core keyframes (or even messing with them at all, kinda add an extra layer of animation on top of the existing one, so to speak). And once that is done, I’d like to bake both into one Action.

Is it possible in Blender? How would I do it?


There are a set of secondary transformations called Delta Transform (under Object Context). You can animate these for secondary animations. Say you have an object moving along the X,Y,Z axis. You could add a single keyframe to the Z delta and add a noise modifier to that channel. Then as your object moved, it would randomly bounce along the Z axis as well.

I forgot to mention it’s for character animation.

Look up the NLA editor.
You can have multiple actions on the same objects and layer them.
Though the functionality is not the same as Mayas animation layers…you could achieve similar results.
Do read up on the Nla editor… might be the solution for your needs.


Yeah, I understand how to mix Actions. For example if I have walking ad waving Actions, I can mix them into one Action - Walking and Waving at the same time. That’s not what I need.

Think about it as if you have an Action with walking anim. Then you want to add saddle movement to the character’s shoulders. Secondary motion in other words. The way I think of it is you would only tweak shoulder bones, and store new “corrective” keys only for those bones in a new Action. NLA would still mix those 2 Actions, but you only tweak keys in the secondary motion layer only for shoulder bones to adjust secondary motion. Those keys would add in runtime to the core animation action. Once you achieve desired result, you could bake core animation for whole body and secondary motions for shoulders into one final Action.

Can Blender do that? I can’t find any info about it. All tutorials for NLA and docs only talk about 2 different Actions mixing (like walk and wave, etc.) where each Action has different bones animated.

I recall 3DS MAX CAT could do corrective animation keys for existing animation keys.

In other words, if you think of it as 2 layers, the core animation Action (complete walk cycle for example) would be in the bottom layer, and shoulders secondary motion animation Action with keys only for shoulder bones is in the top layer (note that shoulder bones in the bottom layer would have keys set for shoulder bones, and keys from shoulder bones from the top layer would be added/blended to the keys of the shoulder bones from the bottom layer)

Am I making any sense? :slight_smile:

In the Dope-sheet, go to the Action Editor, click “+” near the name of the Action you want modify, so you have another independent copy that you can change as you like.

I guess I am not explaining what I would like to do in clear comprehensive way :confused:

In the NLA’s properties shelf there are blending options to blend action strips and also to blend the total NLA result with whatever action is active in the action editor. Replace (default), Add, Subtract, and Multiply are the options. These blend multiple actions of the same bones but I don’t think it works as straight forward as you want.


Aye, thanks. The key issue is that second layer of animation (secondary motion Action) needs to have bones and keys for those bones, that are going to have secondary motion. Is that something can be done in Blender?

I don’t think Blender can do it. I can draw up a visualization of what I am after. Think of it as image layers in GIMP - bottom layer is core animation with keys, top layer has no keys. I add extra keys to the top layer, or corrective layer, to create secondary motion. And then add/blend top layer keys with bottom layer keys to final animation (NOTE: top layer is corrective and relies on bottom layer; top layer couldn’t exist without bottom one as it references animation from the bottom layer).

Bones do support Delta animation as well. The attached file shows a bone animation made up of LOC/ROT in pose mode being modulated by a f-curve modifier on the Delta X.


266_secondary_bone_animation.blend (82.3 KB)

I got that Atom, but do you animate your characters via F-curves or moving bones in 3D view? Also, how would you make deltas and normal transforms into one Action?

Did you ever found a solution for this? It works nice to get the delta value by working in the the fcurves editor, but I would like to move the bones in the 3d view.
Can I somehow get a delta rotation/location option in the keying sets for bones. Now it only works for objects.
I need the delta values to use the add option in the NLA editor right?