spec_values["use_base_color_map"] = (base_color.texture!=0);
spec_values["use_normal_map"] = (normal.texture!=0);
spec_values["use_metalness_map"] = (metalness.texture!=0);
spec_values["use_base_color_map"] = (base_color.texture!=0);
spec_values["use_normal_map"] = (normal.texture!=0);
spec_values["use_metalness_map"] = (metalness.texture!=0);