IK lagging 1 frame when editing animation?

When animating for example a leg the leg itself lags one frame behind the empty that controls the ik chain when browsing the timeline with arrow keys. Also when I move the empty somewhere, decide not to move, and release it with ESC, the empty get’s where it was before but the leg stays in the new position. Going one frame forward and backward again fixes this.

How to make blender sync the whole rig every frame? It’s very difficult to animate like this. I’m using the official 2.4 release in linux.

Here’s a screenshot, you can see from the other leg where the handles should be. The character is taking a step forward here.

You’ll have to post the .blend.

I can’t see from the pic why you have IK’s on both the foot and the shin and what the target(s) are for each. It seems there’s a conflict there somewhere but I can’t repeat it with my simple tests.


Here’s the blend file with some simple animation. The rig is actually a “modernised” version of the foot rig that can be found in the docs, just using the new empties as IK targets instead of the old null bone + ik bone -system.


Ok hari’ from #blender got it figured out… It seems that when mixing IK and constraints to objects outside the Armature (IK target empties in this case) it just doesn’t update as you’d think it should.

So I guess I have to make the rig to work without empties.

I know this problem, too.
But rigging without constraints cannot be the solution, because this lagging thingy - especially on aborting transformations - happens on only constraint rigged scenes (eg. mechanics), too.
and what shall I do then? It’s not really possible then to work without constraints or empties.

So I posted this as a bug in bugtracker a few days ago.

I worked around it by replacing the empties (as ik targets) with null-bones in the same armature. Then it works.

Just got the message from the bugtracker: it really seems to be a bug (in blender’s dependency graph); it will be worked on the problem. :slight_smile:

I do not know, when it will be fixed - I just post it here for information.