Rigged Mesh Flickering

Bug Reports Engine Bugs
#1

Reproduction Steps
This bug happens with rigged meshes imported using the Avatar Importer. I’m not 100% sure if the number of joints makes a difference, but my rig is an arm+hand with 22 joints.

Seems to be performance dependent, however my system is beefy… (AMD Ryzen 9 3950x, RTX 2070 Super, 32 GB DDR4 3200)
I can get this bug to occur by moving several of these rigs at once, OR lowering performance by starting a server with 2 players in Studio Test mode.

Every time each rig’s bone CFrames are updated manually using a script, some of the rigs will update normally. Others however will revert to their default pose for a frame or two, before updating to the new bone positions.

In my own place, I can get this to reliably occur by updating 8 or more of these 22 bone rigs on the server side, then viewing it from the client. Oddly enough, the same rigs don’t do that in Play Solo within studio, however the clientside rigs will start doing it instead.

Expected Behavior
I expect the mesh rigs to update normally without any visual problems.

Actual Behavior
The mesh will revert to it’s default pose every time the joints are changed. In the video below I do this every 0.3 seconds on the server… the rigs that are flickering are the ones being updated serverside.

This bug appears to be entirely visually, the bone positions aren’t actually reverting back to the original pose, the mesh itself is.

This causes a really annoying flickering effect.

Workaround
I do not have a work around that doesn’t involve just not using rigged meshes. Limiting the amount of them that exist at one time is the only fix I’ve found.

Issue Area: Engine
Issue Type: Other
Impact: High
Frequency: Constantly
Date First Experienced: 2021-07-08 18:07:00 (-04:00)
Date Last Experienced: 2021-07-09 19:07:00 (-04:00)

11 Likes
#2

I also have a similar issue, but it happens at a much lesser frequency. All my skinned mesh animations are also client-side and they seems to flicker randomly or when I am changing the transparency for the rig.

#3

The frequency I’ve found is related to how often the part or it’s children is updated in some way. The randomness of it seems to be entirely performance related, note how some of the rigs in the video don’t flicker at all, while most do.

The thought occurs to me that I didn’t include the fact that I’m using “SurfaceAppearance” for texturing, that might play a role in the flicker.

#4

There are a surprising amount of flickering issues with skinned mesh rigs for some reason. In my case, if you were around another player/npc that had a humanoid/humanoidrootpart, then you would start flickering back to your rest pose and become able to clip through objects as if there were no collisions for those brief seconds. All this, only near other players/npcs
I had no idea how to fix it for a week, then as I was messing around with random properties I found out that you had to set the HumanoidRootPart’s RootPriority to be negative. To be safe I set it to -50. I recommend you do the same and check if it helps.

I also still have animation related flickering issues (if a lot of animations are played in high succession, the mesh will try to revert back to its original position inbetween the played animations), or when the mesh is updated in any way, which is something that a ton of other people have reported as well. So I expect a fix coming soon. Or not.

#5

I actually did my own work around that got away from rigged meshes for the humanoids, now the parts are just split up like normal R15 parts, but thank goodness 3rd person animations aren’t SUPER important for my game’s design.

#6

Been having this issue myself for a long while now, it happens when you change absolutely any visual property of a skinned mesh including texture, material, transparency, etc. I was told by staff that it would be fixed by the end of the year back in October of 2020, but it doesn’t seem to have happened. None of the alternate solutions they offered worked for my project so I was forced to put it on ice.

1 Like
#7

Perhaps this is the same issue?

#8

Definitely related, probably the same bug causes both problems

#9

Adding my name to the flickering list. I posted in the original skinned mesh thread, but came here looking for solutions. Some additional behaviors in my case:

  • the T pose only shows up online. It is skipped on the studio, so the animation looks jittery, but does not flicker.
  • I only have one model running one idle animation

Not culprits:

  • FBX animations (80% sure). I can reproduce flickering with a single bone manually animated in studio.
  • my in game script.

Possible culprits:
*HumanoidRootPart is a Part, not a skinned mesh part, which by the rules of skinned meshes . This part is created by the importer, so I’m at a loss how to rule this out.
*Bones that the importer ignores. There are dozens of bones that simply are not loaded into Roblox. Their animation data is loaded but something about the armature is not.

Because this is not showing up everywhere, I strongly suspect it is the uniqueness of our rigging that causes the problem. I am going to dig deeper.

2 Likes
#10

I also have a similar issue but it only happens during server-client replication where it goes t- pose for a single frame once in a while.

I also encountered this new similar texture bug exclusively on mobile:

What’s on here that is relevant:

Blender Animation
High Poly MeshPart with Performance RenderFidelity
Transparency AlphaMode with 2K quality ColorMap and NormalMap

Device: iPhone 12 Pro Max

Only meshpart with pbr texture seems to flicker like the videos shown. No bugs on PC though. Tested on both lowest and max settings on mobile.

Please help or anyone with bug report permission, please forward to roblox!

Video link: Fanglongmon Skinned Mesh Texture Flicker bugs - YouTube

1 Like
#11

The roblox team does know about it from the skinned mesh announcement thread. I think most of us are hoping to determine the cause and work around it for now.

The most common cause is manipulation of the mesh properties while it is animating. Mine might be from a server side torch flame.

I will share as I learn more.

#12

The issue here is it only happens on animated mesh with pbr texture and it only appears on mobile. Everything is fine on PC though.

#13

Anyone awaiting this fix, now’s the time to check your models!