Dev Build Crashes when changing Vertex Color

Hello everyone !

Well i am trying to alter the vertex color in my game , and this is working great in Editor.
For testing purposes i used the node “Paint Vertices Single Color” on a simple static mesh.(new project)

And as stated in the question this causes the game to crash in a Dev. Build.
It does not cause the game to crash in a Shipping Build.

Is this the intended behaviour?

Hi exxello,

  • Does this occur in a clean, blank project with no additional content or is it limited to one champion?
  • What steps can I take to reproduce this on my end?
  • Can you post your crashlogs here so I can take a look? They can be found at \Unreal Projects\PROJECTNAME\saved\logs.

Hi ,

  • Yes this is occuring in a clean project without any additional content .
  • Create a new blueprint project without any content, create a blueprint with a static mesh and within the tick function or anywhere else use "Paint Vertices Single Color " on that mesh.
    This should work in editor . But the Dev build crashes .

Here the crashlog:

link text

When you did this, did you follow the instructions here to set up vertex painting?

isnt this only relevant for the leveleditor ?
The editor itselfe does not crash when using the vertex paint tool.
What i am trying to do is change the vertex color at runtime and the builded game then crashes when trying to do so (works in a shipping build)

Even at runtime you will still need to ensure the material can accept vertex color data. If you add the vertex color node to a material, do you see a difference?

Yes i created a material that only displays the vertex color ^^ and yes in editor and in a shipping build i see the vertex color change

Do you have a sample project this is occurring in you’d be willing to share or steps I can take to reproduce this on my end? I’ll be happy to take a look and see what may be occurring.

Oh yes sure here

I was able to reproduce this on my end and have entered a bug report, UE-31872, to be assessed by the development staff.

Hi exxello,

I was put in charge of investigating this issue. I noticed that while testing I could only reproduce the crash when setting the vertex color on event tick or If I set the color more than once using a delay. If I set the color once using begin play the issue didn’t occur.

So to be more precise if there is already vertex color information painted using this node and you try to add a new color that is what causes the crash.

I updated the ticket with additional information regarding this here: Unreal Engine Issues and Bug Tracker (UE-31872)

You can track the report’s status as the issue is reviewed by our development staff. Please be aware that this issue may not be prioritized or fixed soon. I will reopen this ticket to ensure that it gets re-evaluated.