message: minor fix for the specular param of Principled
diff: @@ -159,6 +159,7 @@ const varying BSDF* varying Principled_getBSDF(const uniform PathTraceMaterial*
  varying BSDF* uniform baseBsdf = MultiBSDF_create(ctx);
  const vec3f baseColor = clamp(self->baseColor * get3f(self->baseColorMap, dg.st, make_vec3f(1.f)) * make_vec3f(dg.color));
  + const float specular = clamp(self->specular * get1f(self->specularMap, dg.st, 1.f));
  const float metallic = clamp(self->metallic * get1f(self->metallicMap, dg.st, 1.f));
  const float roughness = clamp(self->roughness * get1f(self->roughnessMap, dg.st, 1.f));
  const float anisotropy = clamp(self->anisotropy * get1f(self->anisotropyMap, dg.st, 1.f));
  @@ -169,7 +170,6 @@ const varying BSDF* varying Principled_getBSDF(const uniform PathTraceMaterial*
  if (dielectric > EPS)
  {
  const float transmission = clamp(self->transmission * get1f(self->transmissionMap, dg.st, 1.f));
  - const float specular = clamp(self->specular * get1f(self->specularMap, dg.st, 1.f));
  float ior = self->ior * get1f(self->iorMap, dg.st, 1.f);
  if (ior < 1.f) ior = rcp(ior);
  @@ -268,19 +268,20 @@ const varying BSDF* varying Principled_getBSDF(const uniform PathTraceMaterial*
  }
  }
  - // metal base
  - if (metallic > EPS)
  + // conductor base
  + const float conductor = metallic * specular;
  + if (conductor > EPS)
  {
  const vec3f edgeColor = clamp(self->edgeColor * get3f(self->edgeColorMap, dg.st, make_vec3f(1.f)));
  Fresnel* uniform fresnel = FresnelConductorArtistic_create(ctx, baseColor, edgeColor);
  - varying BSDF* varying metalBsdf;
  + varying BSDF* varying conductorBsdf;
  if (roughness < EPS)
  - metalBsdf = Conductor_create(ctx, frame, fresnel);
  + conductorBsdf = Conductor_create(ctx, frame, fresnel);
  else
  - metalBsdf = MicrofacetConductor_create(ctx, frame, fresnel, roughness, anisotropy);
  + conductorBsdf = MicrofacetConductor_create(ctx, frame, fresnel, roughness, anisotropy);
  - MultiBSDF_add(baseBsdf, metalBsdf, metallic, metallic);
  + MultiBSDF_add(baseBsdf, conductorBsdf, conductor, conductor);
  }
  bsdf = baseBsdf;
  