Animation action strips especially with rigs, not showing

Hello!

I have been working on a fairly complex animation which involves an armature which has things happen to it via combining Action Strips in NLA Editor.

I noticed some of the movement wasn’t happening correctly, and assumed I had accidentally deleted some keyframes.

But upon scrolling randomly around the timeline to try and find the problem, suddenly the correct animation was present again… and then other times it vanishes again.

By experimentation I found that you need to use the playhead controls to go into the time range of an Action Strip to get its effects made present and then go back to the start to watch the full scene from the beginning with all as it should be.

But even this doesn’t seem to work every time.

Is there some kind of command to force Blender to evaluate all actions Strips and Rigs and other animation when at the start of a timeline to ensure all will be rendered animated as intended? Thanks.

Unfortunately, this is a bit of a known bug in the NLA System.

For now, the workaround is to ensure that you have a strip at the bottom of the NLA stack which includes a keyframe for the “rest pose” values of every property keyframed in the strips above.

Thanks.

By ‘rest pose values’, do you only mean for Armatures, or do you mean for the start position of every kind of keyframed thing?

Would this rest pose strip only last for one frame at the start of the animation (a ‘reset’ frame that need not be included in the final animation) or would it have to endure the whole length of the animation? If the latter, won’t it have an unwanted influence on the later movements of things, or does it become overidden by new later NLA strips? You say “at the bottom of the stack”; does the top-to-bottom order of layering NLA strips have an effect on which things overides whichother thing?

Sorry for my ignorance, not very experienced in NLA yet.

  1. By ‘rest pose values’, I’m referring to anything animated in the NLA here
  2. The strip itself can be 1 frame long, but as long as it is made to extend forwards AND backwards, that should be fine.
  3. By “bottom of the stack” I mean placing it on the bottom-most track below the action-line (orange track). The evaluation order for NLA tracks goes from the bottom-most track, accumulating results from the track(s) above it, and finally applying the action result on top of everything. So, we want to place this right at the bottom of the stack, so that every other strip evaluated can either replace its results or blend against it (i.e. fading in/out of an action will now blend that action against the rest pose you defined).

Many thanks!