Static mesh LODs vertex color not updated after reimport

Hello,
I have changed the vertex color of my static mesh (fbx). When I reimport it, the LOD0 is correct, but the other LODs are retaining the old vertex colors. If I import the exact same mesh with another name, it works fine, so it must be a problem in the reimport process.
Of course a workaround is importing a brand new mesh and replacing the old one, but this is not optimal in a big project.
I used Maya 2016 exporting in fbx 2016.
Can you reproduce this issue?

Thanks,

I’m using fbx 2016 because the 2014 has a bug that imports a different material slot for each LOD. And surely it’s about time Unreal updates the pipeline!

I believe you are supposed to use FBX 2014. Sadly I don’t think this will help. I too have had vertex color issues

I don’t believe different material slots is a bug. You might want a cheaper mat from far away. Newer software isn’t always better - Maya is actually the poster child here.

Not that. The bug is having multiple materials in the details panel, not in the static mesh itself

I had a similar issue:

There is currently no solution, I ended up importing it under a different name.

Hi Edoartworks,

Before diving in to the issues you’re seeing with vertex colors I want to address the reimport materials populating the details issue you noticed which has been fixed in 4.13.

This would happen anytime there was a reimport with any LODs. It did not have to be a specific version of FBX that was used. It had been around for quite some time too.


Now onto the Vertex Color issues.

“When I reimport it, the LOD0 is correct, but the other LODs are retaining the old vertex colors.”

This is true in the modeling program as well and is not a UE4 issue that I can see. When I create a mesh with 2 LODs and update the Vertex Colors only the selected LOD when the modifier in 3Ds Max for VertexPainting is added are affected not the entire mesh.

  1. Did vertex painting on the base mesh
  2. Created two lower LODs for the base mesh and grouped them in 3DS Max
  3. Selected the Group and applied a vertex painting modifier on the base mesh LOD
  4. Checked the lower LODs to see if it applied. It did not.

The gif here is switching between the LODs after having applied the vertex painting after the LODs have been setup.

107679-lods2.gif

I know this gif doesn’t necessarily show the detail of the settings here and whatnot, but the principal of it all is explained above with the setup.


Of course a workaround is importing a brand new mesh and replacing the old one, but this is not optimal in a big project.

It may not be immediately obvious but you’ll want to open the static mesh and in the details panel on the right you’ll locate the option for “Import Settings”. Then under the advanced rollout you’ll want to change the “Vertex Color Import Option” to Replace otherwise “Ignore” will be used by default and ignore any updates from the FBX file when reimported.

This should solve your issue, but it won’t with LODs unless you manually fix this in your FBX file.

-Tim

This will replace any previously imported vertex information with an update

Thanks for the detailed answer Tim, my bad for not explaining it better… My issue was in the reimport phase.
Now I tried again and it seems to works fine, maybe I exported it wrong.
Thanks again!