As stated, if you have corners / edges that are 90 degrees to each other, you must have separate smoothing groups or you will have smoothing errors. What you really want to achieve in an ideal situation, is a separate smoothing group at your hard edges, AS WELL AS where your UV splits are. This will make for a beautifully…
could be smoothing groups were turned on during the normal baking process, causing it to bake the smoothing group hard edges into the normals, does this happen with the spec turned on, but normals off?
Well that's half your problem, you can't just use 1 smoothing group. You need to have a smoothing group per hard edge. It may look fine in max but that's because the normals are synced up with it, but they aren't with UDK so you get all the crazy shading errors. You should go over the pc normal map wiki:…
Yes, it does. I baked with 1 smoothing group across the mesh. Wouldn't the texture resolution make the seams blurry if it was the normal map? They're super sharp and conform to the edges exactly. No textures: Could something during the export/import process have split these edges in my UV layout? :s
Are you using FBx to export to unreal? What settings are you using. I've seen some odd triangulation happen using FBx with the wrong settings. It doesn't look like smoothing groups from the position of the seams. What does the wireframe look like in udk? How does this compare to the wireframe in max? Try exporting and…
Your problem has nothing to with smoothing groups, though they're some good tips in general. You need to import your normal map using normal map compression or else the shader will give you bad specular highlights in areas near UV seams. Change TC_Default to TC_NormalMapUncompressed (or one of the other normal map…