message: tf selection
diff: @@ -610,21 +610,27 @@ namespace ospray {
  auto tfNodes = scenegraph->child("transferFunctions").children();
  if (tfNodes.empty())
  return;
  - std::shared_ptr<sg::Node> transferFunction;
  - std::vector<const char*> tfNodeCharList(tfNodes.size(), nullptr);
  + std::vector<std::shared_ptr<sg::Node> > transferFunctions;
  + std::shared_ptr<sg::Node> transferFunction = nullptr;
  + std::string tfNodeListString;
  for (auto& tf : tfNodes)
  {
  - tfNodeCharList.push_back(tf.first.c_str());
  - transferFunction = tf.second;
  + tfNodeListString += tf.second->name() + '\0';
  + transferFunctions.push_back(tf.second);
  }
  - static int selection = 0;
  + static int selection = -1;
  if (ImGui::CollapsingHeader("TransferFunctions", "TransferFunctions", true, true))
  {
  + ImGui::Combo("transferFunction", &selection, tfNodeListString.c_str(), tfNodes.size());
  + if (selection >= 0 && selection < transferFunctions.size())
  + transferFunction = transferFunctions[selection];
  + if (transferFunction) {
  transferFunctionWidget.setSGTF(transferFunction->nodeAs<sg::TransferFunction>());
  transferFunctionWidget.render();
  transferFunctionWidget.drawUi();
  }
  }
  + }
  void ImGuiViewer::guiFindNode()
  {
  