question about Normal map

Krisonrik

When I render my model with Maya, it seem the front side receive light much better than the backside. I had to double the light intensity even quadruple the intensity to render a clear shot. Has anyone else run into these problems before?

Daz

Sounds awfully similar to the issue you described over a year ago i.e that maya software doesn't render normal maps properly out of the box. But actually, looking at your other thread, you're not using tangent space normal maps. That's probably it.

Krisonrik

Yes... can't believe you still remember me. Anyways, I didn't understand normal map enough to understand that red green channel edit that you told me last year. Lol the old problem was side is darker (the right side of the model). Is there some thing that prevents Maya to chock on normal maps out the box? What are some common techniques to fix it while taking a z-brush generated normal map and apply it in maya?

Rob Galanakis

You can DL a Maya "Normal Bump" node from highend3d.com , that will let you render normal maps with Software render.

I think this is the one I used (sorry, reformatted and don't have a copy to make sure):
http://highend3d.com/maya/downloads/shaders/NormalBump2D-for-Maya7-0-3738.html

also try:
http://highend3d.com/maya/downloads/plugins/texturing/NormalMapBump-3745.html

fogmann

Make sure you rendered tangent space map (it will be mostly blue). I don't think Maya's bump node supports world space normals, because you only have a choice of bump and tangent space normals. So when you apply your normal map to your model by plugging it into a bump node, how does the model look in viewport when you turn on High Quality? If it looks good there, then you should be able to render it with mental ray and it will look good. For Maya software you may want to try what Pro420 said, or the normal mapper shading node from http://www.pixero.com/downloads.html

Krisonrik

Well I pluged in the tangent normal now, and I had to set the normal to soft. But in certain areas, the sharp edge still shows up. Does that mean that smooth is the only way to solve this problem? Is there another way around this without increasing my polygon count?

Daz

[ QUOTE ]
Does that mean that smooth is the only way to solve this problem? Is there another way around this without increasing my polygon count?

[/ QUOTE ]

Smooth? Smooth what? What does polygon count have to do with using tangent versus object space maps? Are you subdividing the model now or something? Or are you talking about soft edges? You'd get far better help in general If you:

a) thanked the repliers for their posts, whether you used the advice or not

b) provided much more specific detail. Using words like soft or smooth without a context is pointless.

c) started backing up your problems with images, because quite frankly most of the time its nigh on impossible to understand what you're attempting to explain.

Honestly that's why your threads die so quickly. Your responses so often lack sufficient explanation, that it just requires too much effort on the part of a reader to provide help.

Krisonrik

[ QUOTE ]
[ QUOTE ]
Does that mean that smooth is the only way to solve this problem? Is there another way around this without increasing my polygon count?

[/ QUOTE ]

Smooth? Smooth what? What does polygon count have to do with using tangent versus object space maps? Are you subdividing the model now or something? Or are you talking about soft edges? You'd get far better help in general If you:

a) thanked the repliers for their posts, whether you used the advice or not

b) provided much more specific detail. Using words like soft or smooth without a context is pointless.

c) started backing up your problems with images, because quite frankly most of the time its nigh on impossible to understand what you're attempting to explain.

Honestly that's why your threads die so quickly. Your responses so often lack sufficient explanation, that it just requires too much effort on the part of a reader to provide help.

[/ QUOTE ]

First of all, Thank you Daz for your tips. 2nd of all, sorry to all the kind replys that I received, and I forgot to say thank you. How rude of me (usually I do thank everyone.. I really do ; I was just doing a model prepared for an interview this comming week and completely forgot about comming back to check the forum. To make it sound a little bit more clear. The smooth that I was talking about is the smooth function in maya. Which means that Maya subdivid the model increase the overall polycount. I am still an outsider, so I was little concerned about my polygon count. As of right now, the model I posted in my other thread is about 21000 triangles. I figure anything higher than that would be not accepted by the current industry standard for "next gen" systems.
This is what I mean by having edge shown up on rendering. It doesn't look smooth even with the edge set to soft. But it does gets a lot better when I use the smooth function in Maya. So my question is, is there anyway to avoid this while not using the smooth function?

Whargoul

Just use Mental Ray for rendering normal maps. It handles it natively with no problems - just hook the map up to the bump node, make sure it's set to tangent and you're done.

I don't know why people go to such trouble downloading plugins for the Maya renderer, it just works in MR!

Krisonrik

Thanks, for the MR suggestion. There is something that puzzles me in mental ray. The shadow seems all blocky and dark when I render it through mental ray... especially on the face... it's like a huge square mole. But I can't do ray-trace either... since the polygon is so low, the lowpoly mesh shows up after I turn on mental-ray. Any solution to this problem?

Daz

Why are you even rendering it at all? Your energy is far better spent elsewhere. You just don't need to be rendering this thing yet. Concentrate on your modeling and getting things working technically. Rendering should be the last thing on your mind.

Krisonrik

Sorry Daz, It wasn't like an rendering for show or anything. It's just that I have a habit of render few shots in the middle of the process to make sure thing work alright before I move on. I mean if my normal map chocks and I don't get the problem solved, it's pointless trying to put more detail into the model.