Hello!

Is it possible to directly use Vertex Color information that was applied with Mesh Paint in Unreal in an HDA?
The basic setup would be a Static Mesh instance, painted via Mesh Paint in a level, used as a World Input.

So far I have not been able to get a Cd/color attribute to even show up on that Input when painting directly in Unreal.

I have seen older Forum Posts where it is mentioned that this is a working setup, but no explanation is provided unfortunately

https://www.sidefx.com/forum/topic/90663/ [www.sidefx.com]

for reference, there is also this video that shows the type of Input I would want:
https://www.linkedin.com/posts/alex-1vanov_houdini-unrealengine-techart-activity-7391163233325256704-ulOZ/ [www.linkedin.com]

Any pointers would be greatly appreciated!

Unreal 5.6, Houdini 21.0.671

Hey, this actually tripped me up not too long ago as well.

Nothing has changed on the Houdini Engine side. Unreal made an update recently that requires you to send the vertex paint to your mesh. In the Vertex Color panel, where you have your 'Paint' and 'Fill' options, you need to hit the 'ToMesh' button. This assigns your painting to the actual mesh in the level, then Houdini Engine is able to send that Cd data over.

Let me know if that doesn't do the trick and we trouble shoot some more.

Thx for the reply!

So after a bit of testing with a few different meshes, it seems that the "ToMesh" option also doesn't do anything for me. The only option where a Cd Attribute does show up is if I use a Static Mesh that had Vertex Colors applied when it was imported into Unreal, e.g. from Maya.

For the setup I had in mind it would already be a bit cumbersome to not get the instanced VC from the World Input and be required to apply it to the source Mesh first. But it seems very strange that even that wouldn't work.

Oh no. Here is my process with Session Sync open to preview what is being sent from Unreal. I tested the same workflow on the Houdini version you are on and latest, it looks to be working fine, sending @Cd attributes to the vertices data. If that isn't working at all, it might be worth filing a bug and we can dig a bit deeper into this.