Blender masking roughness with metal map

I’m having a very strange issue. This is my first time rendering a Substance Painter asset in Blender. On any mesh components that are a mix of dialectic/metal the shader is masking off the roughness values of the dialectics and rendering as if the roughness values were pure white, based on the metallic map.

The metal parts of the different mixed dialectic/metal meshes/textures are rendering fine.


Can you show us a screenshot of the model and the relevant maps?

Sorry, I can’t show the asset, but they’re just standard metal/roughness maps. White for metal, black for dialectics. I’ve been using PBR metal rough in game asset production for years and I’ve never seen this behaviour. It renders fine in Toolbag 3 with identical maps. I’m a long-time Max user, but it still doesn’t have MikkT so Cycles is the perfect substitute for offline renders.

I’m sorry, I know it isn’t much help not providing images, but it’s just the way it is on this asset. I’ll do a test asset and post that up if the results are the same.


Have you set non-color data in the relevant maps in the node editor? That’s the only thing I can think of.

Yes, all maps are set for linear workflow. Everything else is working perfectly except this one issue.

Just finished running a test using a simple asset using the same setup and it’s working as expected. Very strange. I’ll keep poking around.

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Cool. The one and only other thing I can think of is it’s related to the Normal map. Sometimes I forget to insert a Normal Map node between by Normal image and the Normal input of a Principled Shader for example.

I found the issue. :slight_smile: All the materials that were assigned in the .FBX exported from Max were defaulting to a specular setting of Zero in the shader. Setting the Spec 0.5 fixes it.

Cheers mate.

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