Maya 2017 - Arnold - Black Seams showing at ai.AmbientOcclusion bake

[Isabel_GalvÃ_o]

I have been having this issue for months now, I can't get rid of black seams in certain mesh. I tried forums, I tried in-world engine help groups, I tried other friends that use 3D softwares and no one is able to give me a direct and simple answer. I am sure my settings must be wrong. I even re-installed Maya 2017 from zero and the error persists.

I have black seams showing on baked aiAmbientOcclusion in Arnold for Maya 2017. I tried several baking settings, filter width, optmize, normalize, soft edges, renderer 2.0 off and on, automatic map, planar map and the seams are there. With mental ray for 2016 we use the Fill Texture Seams and that works, but I can't fix these black seems in Maya 2017. It's always at the UV shell borders.

Here is a link to a gyazo of my final mesh already uploaded into my engine and a gyazo from my Maya 2017. What am I doing wrong?

I am about to give up Arnold.

https://gyazo.com/59faa753924d3887f99a076dcb55516d

https://gyazo.com/9ad3102e0c7702495504e828bc947a01

Praying for an answer!

[zenop · Accepted solution]

Are these seams around your uv shells? If so, try unpremultiplying your baked texture

[Isabel_GalvÃ_o]

Yes, the seams are all around the uv shell borders.

I am baking to texture and so far the unpremultiplying seems to work only with 8bit tiff but Arnold bake to texture result is exr. Am I going the wrong way?

I found the unpremultiplyier on the render settings but it seems to not affect the baking to texture.

[litote]

How do you unpremultiply?

[gshankar165]

could u plz send me that mesh? I will try to fix it. mail id : gshankar165@gmail.com

[litote]

Hello Giriashankar,

I just tested the AO shader on a simple cylinder primitive in Maya. I think you are right about the need to unpremultiply the generated texture file. I can do this in After Effects to fix the black seam lines, but I would prefer to fix it within Maya if that is possible. I tried adding an unpremultiply node but I was unsuccessful. Any ideas?

[gshankar165]

Unpremultiply node is there in maya. But its not working. I ll share if i get any other way to fix the issue

[litote]

Thanks. At least you have confirmed it does not work in Maya. I can still use After Effects to fix it, but not so convenient.

[Isabel_GalvÃ_o]

Hello Everyone, thanks for following my initial comment.

@Greg Hughes

Here is how I fixed it, and unfortunately it wasn't within Maya.

I downloaded another software called xNormal which is free.

This software auto-installs a filter in Photoshop called xNormal.

This is my stetp-by-step:

- render AO with Arnold

- open the exr file in Photoshop in transparency mode

- copy all and paste in place to my UVmap

- defringe the AO layer at 1: layer - matting - defringe - 1

- apply xNormal: filter - xNormal - xN Dilation - factor depends, from 2-20 how the UV is mapped

It will fix all black seams.

It does sound like it's a lot of work added but trust me, it's not and it becomes automatic after a few tries.

I added two keyboard commands for defringe and xNormal to avoid having to go over menus in Photoshop.

In case you are using AO's from substance painter, if you export the textures with infinite dilation you will also not have the black seams.

Thanks!

[litote]

@Isabel Galvão

Thanks Isabel,

Since I have AE and XNormal is only for Windows OS (I use a Mac), I will stick to using AE. It is very simple to fix in AE:

Simply open the texture in AE and Export to render out and for settings click on the Output Module options and set Main Options-Color: Straight (Unmatted).

[litote]

@Isabel Galvão @Girijashankar Senapati

Someone on the Maya forums found the fix:

https://forums.autodesk.com/t5/maya-forum/arnold-ao-shader-causing-black-lines-on-seams/m-p/7810000/...