Problem with recording simulation

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Thanks for reposting this here Anton. There’s a lot going on in this video, so let me try and break it down.

  1. When you record, I expect that top-head control to move with the simulation, which it does seem to do. Is the issue that it isn’t following more closely?
  2. You’ve assigned Markers to controls directly, no joints?
  3. If joints, have you retargeted anything?
  4. When you record, you expect only the selected Markers to receive keyframes from the record?

In the bottom of the viewport, you can see this dotted line, this means Ragdoll isn’t keeping up with the viewport playback and is skipping frames. You’ll see slightly different results between recording (which does include every frame) and playback. The most reliable results happens when you playback every frame. It probably isn’t the cause of your issue, but something to keep in mind generally.

In the original video, I noticed a number of non-defaults in the Record dialog.

  • Include Kinematic Keys, this would keyframe things that aren’t affected by the simulation, in this case anything greyed out. This is typically not necessary, what results do you expect from this option?
  • Auto Cache, this would keep the original simulation around after having been recorded. This can be useful to compare the result with the original simulation, is that why it’s on?
  • Use Selection typically, you’d only assign to things you want to record. What was the reason for ticking this?

My guess would be that this head control is not entirely responsible for the head position and orientation, that there is a Spline IK or similar system behind it. Ragdoll would try and Parent Constrain your control to the simulated Marker. If the Marker can move places your control cannot, your control would lag behind.

The solution typically is to assign to things that move like your character, in this case the spine joints, and then retarget onto the controls responsible for moving this joints. In this case, there is likely more controls involved than just the head, e.g. torso and neck controls.

So, to narrow this down, would you be able to:

  1. Reproduce the problem in a smaller scene, e.g. a scene with just a single joint chain?
  2. Reproduce the problem in a new scene, with just the smaller character? E.g. in a t-pose, with the spine assigned and recorded.