When I export my meshes from Max with tangents and binormals enabled, they are twice the size as when they are not enabled. Is there a performance hit with the meshes with them enabled? Does it effect load times? I have a 100 or so meshes, probably half of them would benefit from having tangents and binormals enabled as they have curved surfaces. I’m just trying to get some information before I go through the process of exporting them. Thanks.
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They’re bitangents, not binormals. Report a bug if Max calls them binormals.
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Mesh size isn’t going to make a performance difference; normal mapping is. The decision is made for you after you decide whether or not you’re using normal mapping.
Maybe were not talking about the same thing. There may, or may not be a normal map used by the shader. I believe the one textured HVAC duct had a normal map. I was curious about exporting mesh’s from max with the information Unity needs to calculate the normals instead of import them.
When you use normal maps, you need tangents. Unity doesn’t store bitangents; they’re calculated in vertex shaders. If you don’t need normal mapping, then there’s no point in storing tangents.
Unity only needs winding data to determine normals, but why would you need Unity to calculate normals? Of course export normals and smoothing groups instead of relying on Unity to calculate them.