Hi guys,

I’m wondering if someone can help me out with this one.

I have a megascans material I’m trying to rebuild in Material X.

For Base Color, Specularity, etc, I use a MtlX Triplanar to apply the textures. I’m using an MtlX Position/MtlX Multiply combo piped into Pos to control the tile size of the textures (thanks Brian). So far so good.

For Normals I’m not entirely sure I’m doing the right thing. I use the same MtlX Triplanar to select the Normal Texture, set the signature to Vector 3 (per the online documentation), then pipe the output into the In of a MtlX Normal Map, then subsequently into the MtlX Standard Surface Normal.

The problem is my model ‘triangulates' in areas and ‘breaks up’ at various seams. In certain areas things look good. In other areas there are clear errors.

Any ideas how to apply a Normal Map when building an MtlX Material? Better yet, does anyone have a working example of a Megascans material ‘converted’ to Material X?

Thanks in advance.

Using a normal map with triplanar mapping doesn't make sense. Normal maps require a well defined tangent space to transform the normal. Triplanar mapping is typically used when there aren't any uv's, which means there aren't any tangents. You could define a tangent space using the projection planes of the triplanar map, but that means each projection would need to compute a shading normal from the tangent normal, and then blend after. Something you could do with a clever shader, but not something built in to materialX.

I see..

I guess I'm wondering how Megascans wraps this into their shader, for example when you export from Bridge to Houdini as a Redshift/Triplanar, I can clearly see a Normal there (under Megascan Files).

In any case thanks for the explanation.

Crounder
I guess I'm wondering how Megascans wraps this into their shader, for example when you export from Bridge to Houdini as a Redshift/Triplanar, I can clearly see a Normal there (under Megascan Files).

Redshift might have a triplanar shader for normal maps that handles it correctly.

You're probably right!

Any resolution for this? i been using normal maps with triplanar before thought its a straightforward thing

Did you find a solution?
I see normal texture issues as well when switching to an MtlX Standard Surface material, but the same surface looks totally fine with a USD Preview Surface material and the good old principal one.