Normal Maps baking wrong

batchix · May 2012

Hey, all. I'm having some interesting problems with baking normal maps. I'm getting a weird effect where Maya renders the normal maps with strange black lines through it.

Uvs are here
Normal map generated by Maya is here
Maya Scene is here

The UVs were generated by using Automatic Mapping. I wanted to make sure it wasn't something that was caused by me not laying out my UVs right. All the normals are faced correctly, nothing's backwards that I can find. The High Poly doesn't have any hard edges and I've been using the Transfer Maps function in it's default state. I tried playing with the settings but it still causes the same problems.

While I've got experience using Maya, it's all been low poly modeling with no normal maps... so it's entirely possible there's just one crucial step that I'm not doing and don't know I'm supposed to do it. It's also possible that my version of Maya is just borked in some way... but I've got no way to tell.

Tidus · May 2012

Simple; it's just the smoothing groups. That object doesn't have any (hard edges), and the render to texture tries do its best... but normal map doesn't do magic. There's no way to smooth a 90º angle.

Try smoothing the whole object, but you should definitely chamfer the edges.

batchix · May 2012

Thanks for the quick reply!

Alright, I took your advice and I added some beveling to the sides of the low poly shape and softened all the edges. I'm working in Maya so I only have the option of hard or soft edges, no smoothing groups. Do I need to do more bevels?

The preview works fine now and looks great, but it still renders wonky. Is it a render setting I've got wrong? My renders in Maya always look blurry compared to renders I've done in Max, so...

here's the updated files:

Uvs
Wireframe
Normal Map

File

And I apologize, I'm trying this on a simple shape before I start banging away on the main project. I want to make sure I understand the basics first.

Gannon · May 2012

your bevels too tight and doesn't resemble the shape it's trying to mirror close enough, Widen your bevel so you get softer edges.

Also fix your uvs, you've got a lot of islands. Sew those bad boys up. Soften the internal edges and harden the borders for each island.

Ace-Angel · May 2012

Increase the 'Padding' to around 8 pixels and see if the Red or Green channel need flipping.

batchix · May 2012

Gannon: I thought that you were supposed to separate hard edges on the UVs for normal maps? At least that's what the tutorials I got showed. I was going through the Colt 1911 tutorial from Gnomon and he splits up the UVs on the gun.

I did sew them together and it helped a little, but I'm still getting weird banding. I added a square detail to the center of the object to see how it would pick that up... and it's just as wonky.

Arc-Angel: Just tried that but I get the same weird results.

This is what I get now. Even if I bake the normal map at a higher resolution or a better quality I still get this weirdness. I tried putting the objects in XNormals and baking it, but when I put the normal maps on in Maya I get the same thing.

I did find that if I use a height map instead I get slightly better results- but I still get artifacts and lumps where there shouldn't be lumps.

Wire Frames
Normals
New Scene

This seems like it should be so much easier... :S

thanks for you help! I appreciate it!

SanderDL · May 2012

Works fine in my Maya:

You might just have to flip the green channel in your normal to make it work correctly.

JamesWild · May 2012

Doesn't look like a flipped map to me; rather than being back to front the bevel on the indent points both ways.

EarthQuake · May 2012

Looks like your normal map is loaded as a bump map, not a normal map.

If you're in max, make sure to load the "normal bump" material and then load the normal into that, instead of simply loading the normal map into the bump slot.

Really you shouldn't be using the default material system/scanline renderer anyway, you should look into real time viewport shaders for viewing normal mapped assets.

MagnificentMicrowave · May 2012

He said it's Maya so changing bump to tangent space normals should do it.

batchix · May 2012

EarthQuake I switched to rendering in Mental Ray instead of Maya Software and now it works great. :S Is that what you mean? I'll look into getting some different shaders and materials. I don't have much experience with using anything but lambert, phong and blinn- especially in Maya.

We never render anything or use normal maps at work, we just export the FBX into unity... so I've had no experience with rendering in Maya. I've rendered in Max, but again I never used normal maps and I didn't have any problems with the default render settings.

But now I know and knowing is half the battle. I hope.

I also fixed the other suggestions and re-saved the file here if you want to look over it.

thanks again guys, I really appreciate all this help.

Normal Maps baking wrong

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