message: no longer using NULL ... ridiculous
diff: @@ -172,7 +172,7 @@ namespace ospray {
  if (node.name == "Integrator")
  return parseIntegratorNode(node);
  std::cout << "warning: unknown sg::Node type '" << node.name << "'" << std::endl;
  - return NULL;
  + return nullptr;
  }
  std::shared_ptr<sg::World> loadOSP(const std::string &fileName)
  