PBR Shader opacity quastion

#2
This topic came up in the past too. According to the wise, transparency isn't part of the PBR standard, so it's not included in C3D. A quick Google search for 'PBR Transparency' shows that many are wondering about/wishing for/making work-arounds for transparency support.
I too would like it - for making alpha channel cut-outs at the very least.

--shift studio.
 
#3
You can have transparent areas in PBR and also on export to glTF. But it is limited and you need to include it directly into your base texture. This can simply be a png with a cut out section. Or you can lower the opacity of the entier image to make it semi-transparent. This will work in Falcon. Octane Render also lacks a trasparency dial in the PBR shader but you can mix it with a spectacular translucent shader - maybe you can do this in Cheetah as well. Of course if it works it will be only for a rendering and not for real time export.
Screen Shot 2018-11-29 at 8.55.36 PM.jpg Texture-Alpha-Transparent.jpg

I just realized in Cheetah you can not mix shaders, only textures :(
 
#4
You can have transparent areas in PBR and also on export to glTF. But it is limited and you need to include it directly into your base texture. This can simply be a png with a cut out section. Or you can lower the opacity of the entier image to make it semi-transparent. This will work in Falcon. Octane Render also lacks a trasparency dial in the PBR shader but you can mix it with a spectacular translucent shader - maybe you can do this in Cheetah as well. Of course if it works it will be only for a rendering and not for real time export.
View attachment 33742 View attachment 33741

I just realized in Cheetah you can not mix shaders, only textures :(
Good work around. Glad you shared that!
— shift studio.
 
#5
Thanks. I'm painting textures in a substance painter. the transparency of textiles would be good for. I try the opacity in alpha channel.
 
#6
I'm also using Substance Painter sometimes. They have a dedicated Opacity shader and you need to turn on the opacity channel. 3dromedar - what is your intended output? Are you rendering in Cheetah or is this for export to a game engine or real-time WebGL viewer? If output is for real time viewers, then there could be some issues as not all viewers seem to interpret alpha the same way. For instance, I am developing a work flow to output glTF assets to be used with the new 3d features of Microsoft PowerPoint and the Microsoft 3d Desktop viewer. Unfortunately, the opacity output from Substance is causing very strange artifacts with overlaying geometry in those applications. I am also using the Khronos group's glTF exporter with Blender, which has a few options for manipulating alpha (for instance, it can be set via baseColor factor instead of directly in the image).
 
#7
FYI - I made a mistake in my earlier post. Octane Render does have an opacity slider in their PBR shader (which they call Universal Material). But using a mix shader with specular material (what they call their transparent shader) gives superior results.
 
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