newmtl Phong
map_Kd diffuse.png
map_Ks specular.png

newmtl PBR
map_Pr roughness.png
map_Pm metalness.png

newmtl Extended
map_Ps sheen.png
map_Pc coat.png
map_Pm metalness.png
map_Ni ior.png
map_d opacity.png
map_Tf transmission.png
map_Ke emission.png