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Static mesh strange normals issue

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    Static mesh strange normals issue

    Hi, I am still learning all the tricks of importing static meshes into unreal. My current project is a warhorn I created in Zbrush, reduced the polygon count and projected normals onto the lower resolution mesh. I am happy with the way the normals look in maya, the seams are not really visible. When I import into Unreal however, there seems to be a lighting issue with the way that the UV seams react on the normals. These images will explain better than I can.

    Baked lighting in Ued

    Dynamic lighting in Ued

    Ued Material Network and model details

    the most important section of my normal map, I created this tangent space map in Zbrush and there are no apparent seams or lighting issues in Zbrush or Maya.

    Normals in Maya hardware render

    Maya hardware render without Normals

    Is there something I have forgotten perhaps? I am still new to this and learning all of the tricks to get things to look very nice in Unreal. let me know if you have any suggestions! Thanks!

    where is the actual seam at is it under the model?


      Separated UV islands for normal maps must be positioned horizontally - for both: diffuse and lightmap channels. Because sometimes it doesn't solve such problems - don't know what's the mathematical reason of that, the best, is to have a continues UV space for such shapes. Also try using non-cubic space, if you cannot fit a single UV island into cubic one.


        apophis3d - the seam that you see in the lighting is an actual seam on the UV map, however the seam is only visible in Unreal

        mslaf- I never thought about that, so you are telling me that the actual rotation of the UV islands will effect how unreal lights them? What exactly do you mean, when you say "positioned horizontally"? Thanks!


          It does. There's a UDN article that describes how to correctly unwrap the UVs for lightmaps. Same rules - that's not mentioned there, applies to diffuse channel. Regarding mirrored seams - which is not the case here, it's not only the orientation that is important but the direction as well.

          See this:



          Hardware renders - assuming that this one on the shot on is based on DirectX - can be based on different pixel lighting code (HLSL/shader code) so the effect here and there doesn't have to be the same.