Normal map error in UE4 vs Toolbag 3

3Dyan

I'm having some trouble getting UE4 to display this specific area of my model correctly. It was baked in Toolbag 3 using MikkTSpace with a triangulated mesh. As you can see, the results display correctly in Toolbag 3, however there are a few rogue triangles visible in UE4.
Any suggestions?

sprunghunt

are you importing the tangents into unreal 4? under the 'Mesh' part of the import rollout there are two dropdowns that let you specify that you want Mikkt normals and to import the normals from the mesh.

https://docs.unrealengine.com/en-us/Engine/Content/Types/StaticMeshes/HowTo/Importing 

3Dyan

I went through the importing options originally and none gave a perfect result I'm afraid.

sprunghunt

3Dyan said:

I went through the importing options originally and none gave a perfect result I'm afraid.

This kind of error is usually caused because you've got a mis-match between the normals that you've baked with and the normals you're importing into the engine. So I'd double check what you're exporting and what you're importing. 

Are you exporting the normals from whatever program you're using? (max? maya? )

3Dyan

I'm using the exact settings shown here when exporting and importing (from max). Only difference is I'm baking with Toolbag 3 as opposed to xNormal, while making sure the tangent space is set to 'Mikk / xNormal' in toolbag. 

https://docs.unrealengine.com/en-us/Engine/Content/Types/Textures/NormalMaps/Creation

It is worth noting that the issue is present only in two small areas across the entire model. It has since been resolved by changing the topology, however I would still like to find a way to avoid it completely.

sprunghunt

3Dyan said:

I'm using the exact settings shown here when exporting and importing (from max). Only difference is I'm baking with Toolbag 3 as opposed to xNormal, while making sure the tangent space is set to 'Mikk / xNormal' in toolbag. 

https://docs.unrealengine.com/en-us/Engine/Content/Types/Textures/NormalMaps/Creation

It is worth noting that the issue is present only in two small areas across the entire model. It has since been resolved by changing the topology, however I would still like to find a way to avoid it completely.

I find for better and more consistent results you should have "tangents and binormals" turned on in the FBX export settings. Then in unreal you should set the normals to "import". Otherwise you can get mismatches between the normals your baker is using and the normals unreal creates.

3Dyan

Hi all, I still haven't found a solution to this issue. I've tried baking in Toolbag, xNormal and Painter, but they all give the same result, and while the bakes always show up correctly in Painter and Toolbag, I'm still getting issues in UE4.