Weird Normal Map Problem

Ne0nfire

Hi guys, I have some problems when baking my normal map for my rather simple mesh.
I'm pretty new to baking maps I have to say and I did a lot of investigation when these problems came up.
All the things I already did:

1. Hardened or softened edges where I want the model to have an hard or soft edge
2. Tried to make sure that the edges have enough geometry to hold the edges
3. UVed the model so that every part which has hard edges has it's seperate uv shell
4. Created a cage inside maya which I then have used in XNormal as an external cage file

I think that's basically it. Of course there is the possibility that I've done something wrong in these above mentioned steps.

Also maybe important to mention is, that the model has an inner depth, since it's supposed to be rendered with a glass material with Arnold.

Screens of my mesh:

As you can see on the normal map (green arrows) and on the render, there are some weird artifacts.

Some more info: I used XNormal for baking the normal map, Maya for modeling the low poly, ZBrush for the detail underneath the model and Arnold to display the normal map.

Thanks in advance guys for everybody who's trying to help!

Marshkin

Keep in mind that baking and I are only friends on an occasional basis, but here are my initial thoughts. 

1 - What is the size different between the low poly and the high? It looks like the low poly is smaller then the high.
2 - Add some edge padding when you bake
3 - You may need more geometry at the top where your form is a circle to better support it. 

Ne0nfire

I used the GoZ option from Maya to export my model directly into ZBrush.
In ZBrush I divided the model a few times and added the details.
Then I exported the model from ZBrush and saved it as my high poly object.
I also added supporting geometry but unfortunately it's still not working.

demigodssw

addd more geometry at the top for baking and then remove it later make sure ur uv is not getting disturbed when adding geometry

musashidan

demigodssw said:

addd more geometry at the top for baking and then remove it later make sure ur uv is not getting disturbed when adding geometry

You can't delete topology after the bake when using tangent space normal maps, as the data is based on the surface/vertex normals. Even if you spin an edge it will disrupt the pixel information.

This can be done with an object space  map and converted to a TS map after the fact. It's called skewmeshing.

demigodssw

But thats how we make lods at the place i am working in(they r mostly for organic models though) 

Ne0nfire

Ok, I solved the problem. I found out that XNormal do not subdivide the mesh while baking.
That's why I got these nasty artifacts in my normal map.
So I just used ZBrush Multi Map Exporter, which apparently subdivides the mesh while baking.

musashidan

Ne0nfire said:

Ok, I solved the problem. I found out that XNormal do not subdivide the mesh while baking.
That's why I got these nasty artifacts in my normal map.
So I just used ZBrush Multi Map Exporter, which apparently subdivides the mesh while baking.

What do you mean subdivided the mesh while baking? Subdividing the mesh is applicable to using displacement  maps because it's affecting the geometry. Normal  maps affect the surface shading. If you are subdividing your low poly at render time then this will disrupt the normal map, unless I'm missing something.

In Zbrush you're baking between levels depending on what level your final silhouette mesh(lowpoly) is.