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Mysterious Hard Edges

Devon M
polycounter lvl 4
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Devon M polycounter lvl 4
Hello all. I've got an odd problem. 

So I've made a kitchen counter in Maya 2016 and imported it over to Unreal 4. It has a flat, top face and roundish edges. Everything is UV'd correctly. The edges are hardened at the UV seams, softened everywhere else. I have a material in Unreal 4 that I'm using with a tileable texture. This material has no normal. The counter uses no normal. 

In the bottom corner, along the counter's top face, there are mysterious hard edges. There are no edges in the base mesh where these mystery edges are located. I'll provide screenshots of the problem area and the base mesh. 

I have a feeling that it may be the rendering of dynamic reflections inside Unreal, but it still artifacts in a pattern somewhat similar to the mesh flow.

I have tried: 
1) Using a different material.
2) Re-UVing it.
3) Unlocking normals, harden edges at UV seams/soften other edges.
4) Exporting as an FBX and OBJ

Pictures:
http://puu.sh/q2IUD/27e9361bd4.png
http://puu.sh/q2IWk/1f00b2af83.jpg
http://puu.sh/q2IYB/c85ef143b4.jpg

Replies

  • Quack!
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    Quack! polycounter lvl 17
    At first glance based on your description is that this is a bit depth/blending problem happening inside of your UE4 material.

    Try making a new, basic material that is pretty shiny with just basic inputs and see if you can force this to happen. (Looks like you might have done this)

    You could also try applying that exact material to unreals plane geo primitive.
  • Obscura
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    Obscura grand marshal polycounter
    *Edited
    Nevermind...
  • Vailias
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    Vailias polycounter lvl 18
    What happens when the whole thing is a single smoothing group? (All edges softenend) 
    My guess is that it is an interpolation issue.
    Since you're not using a normal map you're relying on interpolated vertex normals. Look at where your UV seams are in comparison to where your issues are arising. Two of the corners of that big quad are on seams, so they have hardened normals, and two are soft. The soft vertices have a single normal that is pointing off in an average direction along how that curve flows. The hardened ones have one normal per triangle they attach to and are all going to be pointing in different directions. So you're interpolating from an off angle to a more vertical surface over that entire quad. Ideally this would be nice and smooth, but it seems to have developed some aliasing. 

    Another thing to try: Delete that face. Remake it as a new quad, and then soften your normals. 
    There might just be some wonky mesh data in there.
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