i've setup diffuse and normal map inside my HDA and used opdef:../..?file.tga for them both, but only the diffuse is loading in Unreal. Known thing or am I doing it wrong ?

(and didnt have time to try specular and roughness yet but hoping for all those 4 channels to work since the FBX route seems shut down on roughness).

We don't currently support normal maps when used as separate texture files. We only support normal maps as part of the diffuse texture file, as separate N planes. You could try using COPs to combine your texture file into a single map and pass that COP by poth to your diffuse texture on the SHOP.

Aha, thanks for the answer. couple of follow up questions.

Can I use .rat files that already got image planes in them for this ?

and how would the opdef:../..?file.tga look to use a specific a image plane ? or is it just automated assuming a N channel from a given file name ?

Does the N plane have to be N ? could it be Nt as that is the default name when baking out normalmaps from the new H15 baking feature ?

What are the chanels for spec_rough and spec_clr ? perhaps they are just what I wrote ?

1. Yes you can use .rat. Houdini Engine will convert to a supported type for Unreal automatically.

2. The opdef:.. path doesn't need to change. We just look for specific image planes by name.

3. I believe for Unreal, N has to be N or at least N# where # is an integer between corresponding to which normal channel you want Unreal to use. Nt may not work. We haven't yet caught up with the new baking feature in H15.

4. spec_rough and spec_clr are not yet supported in Unreal as far as I know.

Thanks for the answers. Sounds great.

Follow up question, What channels are currently supported besides diffuse and
normal if any?

EDIT: Perhaps there is some documentation somewhere on what channels map
to what, because I tried to use one of the .rat files from my baking and it didnt
even pick up the color but that is stored in the “diff_clr” channel when you bake
it out..could it be that it should just be the C channel for diffuse ?

We only support diffuse and normal at the moment. If none of those are there, we will use houdini default material, which I believe just samples vertex colors.

oh hm… well then I guess my double python script .OBJ to .FBX through Modo is the best solution for now, since that gives me 3 channels, instead of 2, even though I would like up to 6.

I've logged an RFE for this feature, #72176 .

Hello!

We've started work on this feature; progress can be tracked at
https://github.com/sideeffects/HoudiniEngineForUnreal/issues/6 [github.com]

Thanks.

Hello, work on https://github.com/sideeffects/HoudiniEngineForUnreal/issues/6 [github.com] and RFE #72176 / Add support for other material channels has been completed.

This should be available in H15.0/405

Thanks.