Normal Map problem - Gradually fading?

WhatsThatFunction · Sep 2016

Hi,

I'm new to the normal mapping process, and I can't seem to get this shutter normal correct. I've tried using Maya, xNormal, and Blender transfer maps, and they all give the same result, so I know there's something wrong, but I don't have a clue what it is.

This is what I always get (xNormal in this case), but it shouldn't be fading as it goes down.

Image: https://us.v-cdn.net/5021068/uploads/editor/8g/k9trjefc4img.png

Here's the HP and LP models:

Image: https://us.v-cdn.net/5021068/uploads/editor/jl/u2qhlf5yjevn.png

CharacterCarl · Sep 2016

This problem might happen because of skewing. I can't make much sense of the models as it only shows unlit versions without wireframe.
This doesn't say much about the vertex normals which could be the reason why you're experiencing this:
When your mesh is all smooth edges, raycasts will be smoothed between verts and, hence, they will hit the faces at different angles (not just perpendicular, which is most likely what you want) and result in distortion.
If the LP is just simple box geometry try making it all hard edges, split the UV islands accordingly, bake again and see if that fixes your issue.
When baking in xNormal also make sure to "Use exported normals" instead of "Average Normals" in the low poly tab.

WhatsThatFunction · Sep 2016

DerRazputin said:

This problem might happen because of skewing. I can't make much sense of the models as it only shows unlit versions without wireframe.
This doesn't say much about the vertex normals which could be the reason why you're experiencing this:
When your mesh is all smooth edges, raycasts will be smoothed between verts and, hence, they will hit the faces at different angles (not just perpendicular, which is most likely what you want) and result in distortion.
If the LP is just simple box geometry try making it all hard edges, split the UV islands accordingly, bake again and see if that fixes your issue.
When baking in xNormal also make sure to "Use exported normals" instead of "Average Normals" in the low poly tab.

Thanks for the response. I just tried hardening the edges and faces, and it still didn't work.

vertex_ · Sep 2016

Use the ray distance calculator rather than a cage for that projected detail.

WhatsThatFunction · Oct 2016

I figured it out, thanks for the suggestions. I eventually found I needed to eliminate my 90 degree angles by beveling or subdividing on the HP, as well as setting the edges to smooth on the LP, and its perfect

Valandar · Oct 2016

Yeah, sharp edges on Normal Maps are a bad thing. :P

Normal Map problem - Gradually fading?

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