Convert PBR to Source Traditional Diffuse/Normal/Spec?
polycounter lvl 11
Does anyone know any Substance tool, or standlone tool, that allows me to convert a PBR, in either SpecGloss or RoughnessMetallic, to Source's traditional Diffuse/Normal/Spec maps?
Replies
Not sure I've seen one that is backwards compatible. Should be fairly trivial to convert though.
@EarthQuake has a great tutorial/walkthrough on this:
https://marmoset.co/posts/pbr-texture-conversion/
Converting by hand is a bit tedious since there are many steps. Does Toolbag offer a bake option to bake Diffuse, Normal, Spec from the PBR workflows?
When exporting textures from Substance Painter there's an Output Template for the old Non-PBR Specular Glossiness workflow.
It purportedly converts PBR base color metallic and outputs diffuse, normal and specular + glossiness textures. By default the spec gloss texture is packed with the specular values in the RGB channels and the gloss values in the alpha channel. Haven't tested the accuracy of the conversion. So, it may be necessary to adjust some of the values but the option to export for older workflows is still there.
Addendum: If the output template causes an error during export, use the specular and glossiness outputs from the converted maps column in output template tab and clear the opacity output from the diffuse.
@FrankPolygon Would it be possible to "bake" a diffuse for older engines using Substance Painter? I don't own an license, but would definitely get one if it can help me move from modern maps to traditional more easily.
@armagon Substance painter can bake the combined material channels and view port lighting to a single RGB texture. Just use the 2D view output from the list of converted maps in the output template tab. There should be a trial version of Substance Painter available on Adobe's site.
11/15 Addendum: Existing PBR textures, authored in the metallic workflow, can be imported into Substance Painter and assigned to the appropriate channels in a fill layer. For textures authored in the PBR specular workflow it's also necessary to switch the main shader model to PBR-spec-gloss and add the required input channels.
Both PBR metallic and PBR specular textures can be converted to non-PBR spec+gloss using the appropriate output channels from the Converted maps section of the Output Templates tab in the Export textures popup. Depending on how the textures need to be packed, it may also be necessary to create custom export presets that sample from the correct outputs and pack the texture data into the desired channels in the image files.
Some of the default export configurations are setup incorrectly and can throw errors when pulling data from non-existent channels but this can be resolved by choosing outputs from the Converted maps column.
Though Substance Painter makes this process a bit more convoluted than is necessary, it should work in version 2020 and up. Third party tutorial videos seem to be more up to date on the process than what's listed in the official documentation. Below is an example of the various inputs / outputs and the packing configuration used to generate the last generation textures.
I could not find a way to do it with Painter, but this tool did the job: https://shadermap.com/docs/_pbr_conversion_templates.html
I was able to convert from multiple PBR (SpecGloss, MetallicRough) to Diffuse/Specular without any issues.
Nice find!