message: Make sure we always assign a material
diff: @@ -86,10 +86,10 @@ std::shared_ptr<sg::surface_properties> make_surface_properties(Shape::SP shape)
  {
  auto sp = std::make_shared<sg::surface_properties>();
  - if (auto m = std::dynamic_pointer_cast<MetalMaterial>(shape->material))
  + /*if (auto m = std::dynamic_pointer_cast<MetalMaterial>(shape->material))
  {
  }
  - else if (auto m = std::dynamic_pointer_cast<PlasticMaterial>(shape->material))
  + else*/ if (auto m = std::dynamic_pointer_cast<PlasticMaterial>(shape->material))
  {
  auto obj = std::make_shared<sg::obj_material>();
  @@ -170,6 +170,11 @@ std::shared_ptr<sg::surface_properties> make_surface_properties(Shape::SP shape)
  add_diffuse_texture(sp, m->map_kd);
  }
  + else
  + {
  + // Unsupported material or material is null - assign default obj
  + sp->material() = std::make_shared<sg::obj_material>();
  + }
  return sp;
  }
  