As far as I know, the surface appearance is the only texture like object that supports PBR textures (3d textures) and unfortunately, it is for meshes only. Is there something similar to that but for regular Roblox parts? I am aware of material service however it’s really inconvenient when you want to have multiple textures on different parts - and it is not out for Roblox games yet. Any alternatives?
Material service is really the only way for parts. You can try turning a part into a mesh and apply PBR to it.
Pity, I think surface appearance used to be usable on regular parts before I do not understand the change.
Unfortunately for you, it never was. You probably just used the performant builder plugin on accident and never noticed.
It appears that that’s for the Studio Beta Build only, but if you still wish to test it out, you can download the build here: Avatar Evolution | Building the future of Roblox avatars and more!
However, keep in mind that it may not work as intended if you publish it live into your game considering it’s a Beta build afterall, though I could be wrong since I haven’t tested it out for myself either.