SSS direct/indirect turns out black in texture bake #40060

New Issue

Daniel Salazar · 2014-05-07T02:05:47+02:00

Daniel Salazar commented

2014-05-07 02:05:47 +02:00

System Information

openSUSE 12.3 64bits
NVIDIA 480GTX SC

Blender Version

Broken: f300c15

Short description of error

Baking SSS Color works fine but Direct, Indirect or Combined results in black color

Exact steps for others to reproduce the error

SSSBake.blend

**System Information** openSUSE 12.3 64bits NVIDIA 480GTX SC **Blender Version** Broken: f300c15 **Short description of error** Baking SSS Color works fine but Direct, Indirect or Combined results in black color **Exact steps for others to reproduce the error** [SSSBake.blend](https://archive.blender.org/developer/F87394/SSSBake.blend)

Daniel Salazar commented

2014-05-07 02:05:47 +02:00

Changed status to: 'Open'

Dalai Felinto was assigned by Daniel Salazar

2014-05-07 02:05:47 +02:00

Daniel Salazar commented

2014-05-07 02:05:47 +02:00

Added subscriber: @zanqdo

Dalai Felinto commented

2014-05-07 02:22:58 +02:00

The patch above - D503 - seems to work for your file. At least for SSS Color and SSS Direct:

Top Left: rendered passes (SSS Direct), bottom left: baked SSS Direct; Right: baked SSS shown in the UI

The patch above - [D503](https://archive.blender.org/developer/D503) - seems to work for your file. At least for SSS Color and SSS Direct: ![sss.jpg](https://archive.blender.org/developer/F87400/sss.jpg) Top Left: rendered passes (SSS Direct), bottom left: baked SSS Direct; Right: baked SSS shown in the UI

Dalai Felinto commented

2014-05-07 02:43:00 +02:00

I tried the patch with a more complex object (caterpillar from Gooseberry) and I got a good result for color, but a very strange result for SSS direct (image layout same as above):

Catterpilar SSS Color:
Catterpilar SSS Direct:

I tried the patch with a more complex object (caterpillar from Gooseberry) and I got a good result for color, but a very strange result for SSS direct (image layout same as above): Catterpilar SSS Color: ![sss_caterpillar_color.jpg](https://archive.blender.org/developer/F87407/sss_caterpillar_color.jpg) Catterpilar SSS Direct: ![sss_caterpillar_direct.jpg](https://archive.blender.org/developer/F87409/sss_caterpillar_direct.jpg)

Brecht Van Lommel commented

2014-05-07 12:55:03 +02:00

Added subscriber: @brecht

Brecht Van Lommel commented

2014-05-07 12:55:03 +02:00

I think the problem in that file is with the bump mapping, which fails due to missing ray differentials (sd.dP).

A quick way to solve that would be to add this after shader_setup_from_sample:

sd.dP.dx = sd.dPdu;
sd.dP.dy = sd.dPdv;

That's not quite right, really this should take the UV map used for baking and the image resolution into account, for that you could look at bake_set_vlr_dxyco in Blender Internal if you want, to see how you can get those differentials from a UV map. Getting that right would mainly help for OSL image texture lookups and advanced procedural textures that do antialiasing.

I think the problem in that file is with the bump mapping, which fails due to missing ray differentials (`sd.dP`). A quick way to solve that would be to add this after `shader_setup_from_sample`: ``` sd.dP.dx = sd.dPdu; sd.dP.dy = sd.dPdv; ``` That's not quite right, really this should take the UV map used for baking and the image resolution into account, for that you could look at `bake_set_vlr_dxyco` in Blender Internal if you want, to see how you can get those differentials from a UV map. Getting that right would mainly help for OSL image texture lookups and advanced procedural textures that do antialiasing.

Dalai Felinto commented

2014-05-07 16:02:17 +02:00

Hi Brecht, with the latest changes to D503 the baking seems correct (SSS Direct):

So I'm not sure what did you mean by the bump maps (this file has no node connected to the Displace Input). There is a different issue where materials with a node connected to the Displacement input would fail to bake. I'll see if your suggestion fix that, and if so I will report it separately (or ask someone to do it, with real files ;) and post a patch ... Anyways, I shouldn't drag the other issue in here ;)

Hi Brecht, with the latest changes to [D503](https://archive.blender.org/developer/D503) the baking seems correct (SSS Direct): ![sss-caterpillar-direct.jpg](https://archive.blender.org/developer/F87566/sss-caterpillar-direct.jpg) So I'm not sure what did you mean by the bump maps (this file has no node connected to the Displace Input). There is a different issue where materials with a node connected to the Displacement input would fail to bake. I'll see if your suggestion fix that, and if so I will report it separately (or ask someone to do it, with real files ;) and post a patch ... Anyways, I shouldn't drag the other issue in here ;)

Brecht Van Lommel commented

2014-05-07 16:34:05 +02:00

This file is using a bump node to set the normal for SSS, and it seems to cause issues with SSS indirect.

But yes, this should fix the displacement input as well since that uses the same mechanism and ray differentials as the bump node.

This file is using a bump node to set the normal for SSS, and it seems to cause issues with SSS indirect. But yes, this should fix the displacement input as well since that uses the same mechanism and ray differentials as the bump node.

blender-admin commented

2014-05-07 16:59:25 +02:00

This issue was referenced by blender/blender-addons-contrib@83cdd5887f

This issue was referenced by blender/blender-addons-contrib@83cdd5887f10e1998a434fb1632e0b76ec938d91

blender-admin commented

2014-05-07 16:59:25 +02:00

This issue was referenced by 83cdd5887f

This issue was referenced by 83cdd5887f10e1998a434fb1632e0b76ec938d91

Dalai Felinto commented

2014-05-07 17:03:11 +02:00

Changed status from 'Open' to: 'Resolved'

Dalai Felinto closed this issue

2014-05-07 17:03:11 +02:00

Dalai Felinto commented

2014-05-07 17:03:11 +02:00

Closed by commit 83cdd5887f.

Closed by commit 83cdd5887f.

Dalai Felinto commented

2014-05-07 17:40:42 +02:00

Ah ok, I haven't tried SSS indirect. I tried your suggestion (sd.dP.dx, sd.dP.dy) and it works for displacement in the sense that it doesn't produce black. However it seems to simply bypass the displacement. I reported it here #40068 so we can discuss it there.

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SSS direct/indirect turns out black in texture bake #40060