Need help with Normal mapping and UVs
polycounter lvl 7
I wonder if anyone could help me with an issue I encountered with normal mapping and overlapping UVs while making a set for the DOTA2 contest.
First I made the mistake of importing the objects into Zbrush and trying to create the normal map with the UVs overlapping, which created a normal map that could not be used.
In order to fix this issue I took the overlapping UVs and placed them outside the 0-1 space, but the Normal map was deformed still (motion blurred).
I finally decided to delete the half of the geometry that would be duplicated, create the normal map in Zbrush and then duplicate what needed to be mirrored in Maya.
I thought that would work well, but could not verify as maya kept crashing when I tried to render with a normal map.
After reinstalling maya, I was finally able to test the map, and the mirrored geometry appeared with the normal mapping inverted (what should have appeared as bumped, appeared to go inwards).
I have tested this with 3 different renders, using:
Mental Ray: normal mapping inverted
Maya Sofware: normal mapping inverted
Maya Hardware: It worked!
After doing some research it seems that in 3Ds Max this inversion does not happen, and that most recent game engines do support mirrored normal maps.
I could not find if that was the case for DOTA2, but I assume it is since we are encouraged to overlap UVs.
Does anyone know for sure if DOTA2 supports mirrored normal mapping, as that would mean I would not have to rework my UVs, redo the normal maps and textures, and lose texture space.
First I made the mistake of importing the objects into Zbrush and trying to create the normal map with the UVs overlapping, which created a normal map that could not be used.
In order to fix this issue I took the overlapping UVs and placed them outside the 0-1 space, but the Normal map was deformed still (motion blurred).
I finally decided to delete the half of the geometry that would be duplicated, create the normal map in Zbrush and then duplicate what needed to be mirrored in Maya.
I thought that would work well, but could not verify as maya kept crashing when I tried to render with a normal map.
After reinstalling maya, I was finally able to test the map, and the mirrored geometry appeared with the normal mapping inverted (what should have appeared as bumped, appeared to go inwards).
I have tested this with 3 different renders, using:
Mental Ray: normal mapping inverted
Maya Sofware: normal mapping inverted
Maya Hardware: It worked!
After doing some research it seems that in 3Ds Max this inversion does not happen, and that most recent game engines do support mirrored normal maps.
I could not find if that was the case for DOTA2, but I assume it is since we are encouraged to overlap UVs.
Does anyone know for sure if DOTA2 supports mirrored normal mapping, as that would mean I would not have to rework my UVs, redo the normal maps and textures, and lose texture space.
Replies
What version of maya are you using? Mirrored normal maps have worked fine in "high quality" and "viewport 2.0" render modes since at least 2011.
Any version since 2012 (possibly before) supports mirrored normal maps with maya hardware rendering.
Using mental ray to render should work fine as long as you check "use maya derivatives" in the options panel of the render settings.