I am using Substance Painter 2018.3 and want to export my PBR material for babylon.js. The documentation of Babylon.js states:
metallicRoughnessTexture: Texture containing both the metallic value in the B channel and the roughness value in the G channel to keep better precision. Ambient occlusion can also be saved in R channel.
I've read that Substance once had an export preset (for gltf textures), but it seems like they removed it. So how do I get Roughness and Metallic into one .png using the B and G channel?