Can I use half normal for a symmetrical model?
by Peng Du · in Technical Issues · 04/23/2007 (12:30 am) · 3 replies
The workflow should be like this:
1. Make half of the model
2. Generate UV for the model
3. Make the other half of the model by Symmetry modifier, so the UV is mirror and occupy the same location as the first half
Here every textures are half, including normal map. But the lighting on the 2nd half will be wrong due to mirrored UV.
My question is how I can modify the engine to display the 2nd half's normal map correctly. I know it is possible, but how?
Or how can I make the shader?
Thanks in advance!
1. Make half of the model
2. Generate UV for the model
3. Make the other half of the model by Symmetry modifier, so the UV is mirror and occupy the same location as the first half
Here every textures are half, including normal map. But the lighting on the 2nd half will be wrong due to mirrored UV.
My question is how I can modify the engine to display the 2nd half's normal map correctly. I know it is possible, but how?
Or how can I make the shader?
Thanks in advance!
#2
UV is flipped for the Symmetry-ed part, occupies the same location as the UV of the original part, so that textures can be reused.
Lighting direction on the Symmetry-ed part is wrong. If you unwrap the entire UV and don't use UV flipping, there will not be this issue.
The key point is, normal map cannot be used on flipped UV.
05/06/2007 (9:39 pm)
I use 3ds max.UV is flipped for the Symmetry-ed part, occupies the same location as the UV of the original part, so that textures can be reused.
Lighting direction on the Symmetry-ed part is wrong. If you unwrap the entire UV and don't use UV flipping, there will not be this issue.
The key point is, normal map cannot be used on flipped UV.
#3
You have your current UV layout symmetrical right? Try saving those UV's under the Unwrap UVW modifer and name it something like set1 and then open the Edit function also under Unwrap and go to Mapping , Flatten Mapping. Now save that as set 2. Now load the first UV set, save the model and re-export.
I hope that helps.
05/30/2007 (8:39 pm)
Not sure this will work or not for Torque, but it has worked for me in other simliar situations for other engines namely Unreal 3. You have your current UV layout symmetrical right? Try saving those UV's under the Unwrap UVW modifer and name it something like set1 and then open the Edit function also under Unwrap and go to Mapping , Flatten Mapping. Now save that as set 2. Now load the first UV set, save the model and re-export.
I hope that helps.
Torque Owner Lee Latham
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I presume so. What are you seeing/not seeing? It's hard to help without a description of the problem.
Did you try inverting vertex order/flipping the faces? What tool are you using?