Mesh snapping/jilting/flickering when ragdolling

Development Character & Animation
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1

Hello! Nice to see an active forum of game developers.

I have a problem with mesh snapping/jittering at the beginning of the ragdoll. To update capsule component position with position of the mesh on the map, during ragdoll on every tick I move the capsule component with the “Set Actor Location and Rotation” node. However, it’s buggy; you can see it in the clip below.

To force mesh to keep its rotation/location when getting up, in PA_Mannequin I’ve added a sphere and constraint between root and pelvis. As you can see in the video it doesn’t work perfectly because after getting up Manny is not facing the correct direction.

I’ve spent 3 days debugging and this is what I’ve found:

  • bug happens because I call “Set Actor Location and Rotation” on tick when the mesh is ragdolling. If I don’t update actor location and rotation, mesh is not flickering.
  • If I skip “Set Actor Location and Rotation” on the first tick, the bug is somewhat fixed but not really. It works better in 99% of the cases but it can still happen sometimes.
  • I was not able to reproduce problem in different, similar projects. It makes me think something is wrong in my PA_Mannequin configuration.
  • If I don’t create in PA_Mannequing constraint between root and pelvis, and set it’s to “Angular drive mode” to “twist and swing”, snapping is even worse. I can provide video if needed.

So, can anyone help me? I think I’ve reached my limit and I’ve tried 3 different tutorials on ragdoll, none of them worked perfectly. Please help!

2

Day 4 of debugging:

I’ve fixed wrong direction of a character getting up but the flickering issue persists.

Here is node calculating position of the actor:

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And in my enemy BP, I just use “Set Actor Location And Rotation” node. (screen shot in next comment)

3

Screen shot showing update of enemy location and rotation. Without it there is no flickering but ragdolling feature doesn’t work as intended (capsule position is not updated correctly).

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4

Alright, kinda fixed it but not in 100%, there is still some flickering but it’s manageable. Worst part of flickering at the beginning when the character teleported up is fixed. For now it’s good enough.

The problem was that I initially updated the capsule component always at height + (0,0,90), which caused the mesh to teleport up. I’ve fixed it by calculating the distance from the ground on each tick and inversely decreasing the Z location. Here is the full BP; maybe someone will have the same problem.

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Cheers!