I am creating materials in Threekit from texture files. I have Glossiness maps and I do not see a way to use these in a Threekit material.
Glossiness and roughness map define the same type of information, however, they do it on an inverted scale. Roughness maps use lighter values to define surfaces to be rough/matte, while glossiness maps use lighter values to define surfaces to be glossy/shiny.
The Threekit platform uses roughness for materials. If you have a glossiness maps you must simply invert it. To do this open the texture asset in the Threekit platform, look under the “Color Transform” section and check the “Invert” box. This will convert your glossiness map to a roughness map.