normal map problems

etsuja

When I generate normal maps I get seams where I split my model for UV mapping. The seams are closed of coarse after setting up the UV's, LW users will know what I'm talking about. Is it up to the shader to solve normal map seams?

etsuja

Also, when I use tangent space for the normal map it looks nothing like it should when I render it in LW layout. Is that just the shaders fault?

etsuja

I did some testing and here's what I'm talking about...

this is closer to the way I want it to look but this is object space which I've read won't work too well with deforming characters...



and here's tangent space... comes out with the light inverted or something.



These were both rendered in lightwave.

Ghostscape

it's the shader's fault.

try flipping the red and/or green channels, the problem is that the normal map is being rendered with Red+ being right instead of left, or vice versa, and/or Green+ being up instead of down, or vice versa.

Looking at that it looks like you'll need to flip both the red and the green channels to get it to light correctly.

etsuja

How do I flip the channels?

aesir

go into photoshop. go to the channels tab which is right next to the layers tab. Select a channel. Invert.

etsuja

Oh, tried that but still doesn't render right.

etsuja

How do people get wicked looking normal mapped character renders with tangent space?... everything I've tried looks horrible.

Noren

It kind of looks like your shader would read the tangentspace normalmap as objectspace, too. Perhaps there is a checkbox somewhere that tells the shader how to interpret the normalmap.

etsuja

I actually don't think this shader/plugin can do tangent space at all after reading about it more.

etsuja

what programs do people use to get good tangent space renders? I either get wierd lighting or gouraud crappiness on my renders.

MoP

You could try XNormal - www.xnormal.net
Be sure to get the documentation and read it too, if you don't understand how the program works. It's very good for creating and displaying tangent-space normal maps!
Best of all, it's free

etsuja

sweet, I'll check it out. Thanks dude.