subsurface and metallic combine into a material


i have some question about combining subsurface and metallic into a material, is there any way to create it like using material function or any method?


Not really. The G-buffer cannot handle adding one more pass to separate metallic materials from subsurface. It’s one of the limitations of deferred shading. You can use emissive to cheaply fake subsurface illumination on a surface containing metals, but that’s about it. You can separate materials at the polygon level to define metals from subsurface that way. That’s the ideal way to do it.