4.8 Apex Cloth "trembling" on playable Character

I just converted my project to 4.8 and the apex cloth is “trembling” while playing the game.
This does not happen while viewing the skeletal mesh in the editor only when playing (in editor or not).
This only happens to my playable character, If I place the mesh like a object the problem is gone.
In 4.7 everything works as it should.

I tried reimporting and deleting then reimporting the apex assets with no luck.

Hi ,

Would you be able to post a video demonstrating the “Tremble” that you’ve described? I’ve not been able to see this in any of our Content Examples assets where I can test. I looked at the Owen character in the Animation map of Content Examples that is available via the marketplace.

Thank you!

sure, there you go:

its subtle but visible, its way more visible with motion blur turned on:


this is the same character in 4.8 in persona:

in 4.7 this problem was not present. Nothing has been changed on my end.

thanks for looking into this

The cloth in the content example for 4.8 is working as expected when I try it out.
So this means something isnt right with my cloth? Do you have any idea what could be the cause? I tried everything I could think of.

Any update on this?
I cant figure out what is going on.

Apologies for the delay. I’ve had other priorities I’ve had to get to first.

I’ve spent some time this morning trying to replicate the trembling, but I’m not seeing that on my end with a basic cloth asset and character mesh that I created in 3Ds Max.

If you have a test asset that can recreate this I can take a look when I get time, but with my couple of test thus far I’m not able to see the same results unfortunately.

Let me know.

Same problem. As if included simulated wind. In the editor, everything is fine but the gameplay clothing simulated wind.
sorry for bad english

I was able to dig into this one a little bit more and was able to see thanks to ZzGERTzZ’s suggestion that wind was having a factor in the tremble.

It looks like wind is on by default for cloth assets whether there is a Wind Directional Source actor in the scene or not. I’ve reported this with UE-17470.

For the moment you can just place a WDS actor in the scene and set the strength to 0 to get rid of the “tremble” that you’re seeing. I will update once there is a fix in for this.

Thank you!

Thank you for looking further into this.
Placing a WDS and setting its strength to 0 sadly does not stop the trembling.

I managed to narow down the problem further:
Cloth assets are only trembling when attached to a playable character with a “Cloth Blend Weight” other than 1 or 0.

I tested this with the character from the content examples and had the same problem.

Hi ,

I wanted to update you on this. I was able to track this down a little bit further and it appears to be something either that is set wrong with Clothing or something in the Post Process Volume that is causing the issue.

By setting a post process volume that is unbound in your scene and setting the "Motion Blur: Per Object Size: " to a higher value this can resolve the issue for the moment. It will be based on the size of the object in the screen space. For instance. if you setup your character and set the Per Object Size to ~75 seem to correct it for the Owen Character. Also, disabling the motion blur by setting it to 0 resolved the issue as well.

I’ve started a discussion with the developers on this one and will update with what I hear as soon as I know something more.

Hi ,
awesome, thank you for the workaround, setting the motion Blur per object size to a higher number worked for my character.

Disabling motion blur however did not stop the trembling as long as per object size was at the default value.

Hi Loginus,

I just wanted to update you that this has been resolved in our internal build of 4.9, so this will be fixed fully when that is released. Unfortunately, there is no definitive date set for when this will be released yet. Just keep an eye for updates in the launcher for when 4.9 releases.

Thank you!