Instance Keyframes? (like Blender's NLA editor)

[Atom]

Hi All,

I have a character that makes the same gesture several times during an animation. Currently I have created the gesture and then copied and pasted it at the required locations along the timeline.

While I could make a pose for this character I don't see the point. Basically a pose is just a group of keyframes represented by a button. There does not seem to be any way to edit the keyframes in a pose after I create it initially. Also even if there was I can't find a way to ripple those changes into the timeline to reflect the new poses in previously issued pose keyframes. So I have discarded posing as an option and I am back to just adding keyframes.

In Blender you can make a keyframe animation and turn it into an animation strip. This strip can be duplicated, essentially instancing the keyframes to a new place in the timeline. If I go back to the original animation strip and edit the source keyframes all duplicated copies along the timeline will receive that change. Does Houdini have this kind of functionality?

When I Google Houdini Non-Linear all I get is references to CHOPs. But I don't see how CHOPs can instance keyframes. Does anyone have an example of this?

I also looked into Animation Layers thinking, ah this is it. But Animation Layers are just a way to vertically cross mix the same parameter on the same keyframe via a weighting system. Animation Layers are nice, and is also part of Blender's NLA system, but does not allow me to duplicate sets of keyframes horizontally along the timeline. AKAIK

The last time I tried the DopeSheet is was seriously broken to the point of being unusable as of 15.5.565.

 

Typical usage would be separating the animation of a character into upper and lower portions. So the legs can have a walk and the torso may do something else, each loopable on different loop lengths. Then if I need to re-time the walk I could simply edit the keyframes of a single walk cycle and it would loop continuously. As I type this I realize CHOPs can loop but what I am looking for is not necessarily looping. I may require gaps between frame ranges.

 

Hmm...

 

 

Edited September 15, 2016 by Atom

[edward]

Have you tried the cycle() / or cycleoffset() expression functions?

http://www.sidefx.com/docs/houdini/expressions/cycle

http://www.sidefx.com/docs/houdini/expressions/cycleoffset

 

[Atom]

I have looked at that but cycle() won't actually work in this case. Let's say I have a hop, skip and a jump. In an NLA system I can simply arrange them as I need them. Like hop, hop, skip, jump, time stretched hop, jump, jump. Then if I need to revised the style of the hop, I only have to change one keyframe set, the hop, and the rest of the animation will simply be updated.

[edward]

I think CHOPs is the closest answer then sans data instancing. For character motion, it probably doesn't matter much. A lot of the operations you mention can probably be done with CHOPs one way or another.