message: fix GLTF seg-fault with unused node definitions
diff: @@ -601,8 +601,6 @@ namespace ospray {
  return;
  // DEBUG << "Build Scene\n";
  - sceneNodes.resize(model.nodes.size());
  -
  // Process all nodes in default scene
  auto &scene = model.scenes[defaultScene];
  for (const auto &nid : scene.nodes) {
  @@ -614,7 +612,7 @@ namespace ospray {
  // attach (skinned) meshes to correct transform node
  size_t nIdx = 0;
  for (auto n : model.nodes) {
  - if (n.mesh != -1) {
  + if (n.mesh != -1 && nIdx < sceneNodes.size()) {
  auto &ospMesh = ospMeshes[n.mesh];
  auto &targetNode = sceneNodes[nIdx];
  if (n.skin != -1) {
  @@ -655,7 +653,7 @@ namespace ospray {
  else if (ic ==3)
  newXfm->child("robustMode").setValue(true);
  - sceneNodes[nid] = newXfm;
  + sceneNodes.push_back(newXfm);
  sgNode->add(newXfm);
  applyNodeTransform(newXfm, n);
  