Baking color channel

[marcosimonvfx]

Hi,

this seemingly simple thing has bugged me all day and I couldn't get this to work:

I want to bake the color channel of a principled shader to a file.

1. When I create a principled shader and connect my texture to the "basecolor" input I can't see it in the "basecolor" image plane. After trial and error I found that it's in the Cf image plane - why?

2. When I create a baketexture node, plug my object and now say I want to bake the Cf channel, the baked texture is always completely black - When I render the image with a mantra node I can see the texture in the Cf channel. But the baking is always black.

 

Thanks a bunch for any help!

[davpe]

1. because it's a bug I think

2. i assume that's because you have left "Disable lighting and emission" on bake ROP turned on (which is on by default for some reason)

[marcosimonvfx]

Thanks davpe, your help got me on the right track. I managed to output a texture in the Cf channel.

Keeping at this I finally solved the output problem by throwing everything into a materialbuilder and putting my bind_exports there (outside they didn't work). Now also my custom channels get exported, whether the "disable ligthing and emission" is enabled or disabled.

Still though - unless I additionally put a bind export in there and name it "export_basecolor" I don't get a basecolor channel from my principled shader, eventhough if I dive into the principled shader I see the bind export with the same name in there - rather strange. At least like this I can work around it

[davpe]

yeah built-in channels are weird, I always use my own exports. hopefully they'll fix it in the next release.

[lamer3d]

To make proper basecolor output, you need to add hidden mantra parameter Add Baking Exports to Shader Layers

 

[marcosimonvfx]

@lamer3d still doesn't seem to work for me. I mean, it's ok for now, I can get my exports with custom layers. It would just be interesting, why these layers are not there. Even when I don't connect anything in the shader to the base color input and instead load a texture in the "Textures" Tab it comes out black (I also tried to ad the Baking tab to my mantra node).

[davpe]

10 minutes ago, marcosimonvfx said:

@lamer3d still doesn't seem to work for me. I mean, it's ok for now, I can get my exports with custom layers. It would just be interesting, why these layers are not there. Even when I don't connect anything in the shader to the base color input and instead load a texture in the "Textures" Tab it comes out black (I also tried to ad the Baking tab to my mantra node).

when i was looking into this earlier, I came to the conclusion some channels are just exported incorrectly from the principled shader (couldn't really decipher what's wrong there thou). for the classic shader, these exports are not there at all i think. so custom channels are just the best way. i made a shader preset with all the connections i always want and just don't care about predefined channels.