4.9.1 Damage with Morph target and collider bug


I have updated my project to the newest, 4.9.1 version, but that was not my best idea (luckily i have multiple backups from my project).

I think some changes was made to the colliders in the engine.
So the problem is that, in the previous version 4.8.3 the damage of my car using morph targets/colliders was working correctly but with 4.9.1 just isn’t.
When you get some damage on the car, with 4.9.1 the car mesh starts flickering when it’s moving (it looks like it’s jumping between the original undamaged state and the damaged state).
I have uploaded two builds (to see what it should look like in 4.9.1, it’s name is CarTest_4.8.3_X86/CarTest_4.9.1_X86) none of the two was anything changed by hand.
Those builds can be found on the link below under the Builds Download Link.

Someone have any idea, to fix this issue?

Unreal Engine Forum - CarTest

Hello ,

I downloaded both your 4.8.3 and your 4.9.1 versions of your Car Project. I then launched them both individually. Both only return black screens inside of the window.

Hi ,
On my computer both works, also on my father notebook works too.
Should, i recompile and upload it elsewhere, or create a video of my problem and post it here?


The best way for me to test is with your projects. If you could add a link to dropbox here that will be fine.

Okay, so i have recompiled both version tested on two different computer.
On both computer produces the flickering morph targets but only in the 4.9.1 version of the engine.
Also i’m uploading to Dropbox right now, and under 5 min there will both appear.
Dropbox Link

It has ended uploading the files, if it’s starts with a black screen again than just wait 1-2 minute.


Sorry about the earlier confusion. I clicked to activate the window and that seemed to do the trick. So, the interesting part of this is that it only happens some of the time. For instance, if I damage the front of the car and move in reverse then is sometimes see the font flicker. Then in revers for the rear bumper.

What could possibly be happening is your LOD distances need to be moved further apart. I noticed that damage tends to repair itself after a time even if you haven’t picked up the spring yet. So the game may be trying to calculate the first LOD while the damage to the morph targets are in the damage position.

Adjusting the screen sizes in your LOD may also help. Try to tweak those settings so that the Damaged position LOD is at a smaller draw size than your first.


Thanks for the help, then i will change the LOD’s draw size tomorrow, and reply back if that fixes my problem!

EDIT: I have fast checked it out changed the draw size value you sugested, than i pressed play and tested, my problem still exist so i delete all LOD’s to check if it has something to do with my problem and it turned out that it doesn’t. The flickering effect still exist without any LOD. Have you, any idea what is causing it?

Hello ,

So I am going to try and recreate this in a test project. For that I need a little more information from you.

1.) What Kind of Morph Targets are you using? Are you using Skeletal or Static?
2.) Can you link me a copy of your DxDiag?
3.) I can recreate a test from scratch but it would be easier with your unique project and assets. Can you link me a dropbox of your project itself.


Hey ,

I pooled some resources and another one of our team dealt with almost the exact issue. What we see is a flickering when morph targets are called.

This appears to be a bug with our morph target system.

A bug has been entered and will be handled as soon as our development team can.

The ticket number is UE-21684.

I will keep you informed on this bugs progress. I do not have a time table for when this will be handled but I am hoping with multiple people experiencing this issue it will be resolved very soon.

Thank you very much for reporting this.

Thanks for it, waiting for further updates!

Hey Balint,

If you would go ahead and accept that answer I would appreciate it. Sometimes when you comment again it kicks it out.