TypeScript type guard: narrows a Material to PbrMaterialProps when it belongs to the PBR family (see getMaterialFamily). A MaterialView over a PBR source also passes, since it inherits every PBR property through its prototype chain.
TypeScript type guard: narrows a Material to PbrMaterialProps when it belongs to the PBR family (see getMaterialFamily). A MaterialView over a PBR source also passes, since it inherits every PBR property through its prototype chain.