Normal map bake problem

Teapose · Dec 2012

Hello!
I am currently trying to bake out a normal map for a vehicle I have been working on, but for some reason I get these problems all over my normal map. It looks like the edges on my low-poly model is somehow influencing the normal map and leaves these ugly edges... It only happens when I'm using the tangent space normals-method.
I have no idea what to do about it?

To the left is the bake with object space normals and the right is the one with tangent space.

o2_is_alright · Dec 2012

Well it's supposed to look like that. The shading and "ugly edges" are there to compensate for the smoothing on your lowpoly.
The question is whether the normalmap does its job or not. If the model looks alright with the normalmap applied then there's no problem. If it doesn't then it'll be easier to help if you post some additional info and images to illustrate the problem.

Teapose · Dec 2012

No, unfortunately the normal map is not really doing its job

.
It looks okay with the object space normal map but it's not what I want to use.
I wonder if it has anything to do with the way I've split my polygons on my low-poly mesh (the image to the right)? Would it be better to try to not get these long, triangle-shaped polygons, and if so, is it better to add a bit of extra polygons to make them more square?

joeriv · Dec 2012

it kinda looks like you don't have proper smoothing groups set (in this case some of the triangles in your mesh having a completely different smoothing group altough they are basicly in the same "plane" with some minor differences).

So if possible put a screenshot of your lowpoly (without wires and normal map)

Also, why are you modelling in those cutouts in your LP?

Teapose · Dec 2012

I believe smoothing groups are a term used in 3ds Max, right? Maybe I should have mentioned what program I am working in, I'm working in Maya. And I believe all polygons are smoothed the same but with hard edges where I have UV-splits..

Maybe I could remove the cutouts in my lowpoly, that's true, and that might be my only solution, they aren't really that deep. But I've encountered this problem before on other meshes in the past and I'm very curious as to what causes it and how to avoid it the best way possible in the future, aswell.

Here is the lowpoly mesh naked and bare

Marine · Dec 2012

Yes, add more edges, if a few more polys will save you shading headaches, it's worth it.
It's all fairly flat detail too, you could simplify a lot of your low poly and still get a good result, unless you're going to see that bit up close.

Teapose · Dec 2012

Thanks everyone for the replies!

I decided to remove the cutouts after all, it turned out better in the end!

King Mango · Dec 2012

I have noticed that having hard edges anywhere on either the high or low poly during the bake causes undesired results. I always set both objects to all soft.

S_ource · Dec 2012

I think object space normalmaps don't use the normals of the lowpoly at all just override them but tanget space works together with the lowpolys normals.

Normal map bake problem

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