Fix: Works even the root node doesnt have child (#358)

Signed-off by: Onur Berk Tore otore19@ku.edu.tr

Co-authored-by: Luca Della Vedova <luca@openrobotics.org>

graphics/src/AssimpLoader.cc

@@ -86,6 +86,9 @@ ignition::math::Matrix4d AssimpLoader::Implementation::ConvertTransform(const ai
 
 void AssimpLoader::Implementation::RecursiveCreate(const aiScene* scene, const aiNode* node, const ignition::math::Matrix4d& transformation, Mesh* mesh)
 {
+  if (!node)
+    return;
+
   // Visit this node, add the submesh
   ignmsg << "Processing node " << node->mName.C_Str() << " with " << node->mNumMeshes << " meshes" << std::endl;
   for (unsigned mesh_idx = 0; mesh_idx < node->mNumMeshes; ++mesh_idx)
@@ -343,13 +346,11 @@ Mesh *AssimpLoader::Load(const std::string &_filename)
   }
   SkeletonPtr root_skeleton = std::make_shared<Skeleton>(root_skel_node);
   mesh->SetSkeleton(root_skeleton);
-  for (unsigned child_idx = 0; child_idx < root_node->mNumChildren; ++child_idx)
-  {
-    // Now create the meshes
-    // Recursive call to keep track of transforms, mesh is passed by pointer and edited throughout
-    ignmsg << "Parsing root child " << root_node->mChildren[child_idx]->mName.C_Str() << std::endl;
-    this->dataPtr->RecursiveCreate(scene, root_node->mChildren[child_idx], root_transformation, mesh);
-  }
+
+  // Now create the meshes
+  // Recursive call to keep track of transforms, mesh is passed by reference and edited throughout
+  this->dataPtr->RecursiveCreate(scene, root_node, root_transformation, mesh);
+
   // Add the animations
   for (unsigned anim_idx = 0; anim_idx < scene->mNumAnimations; ++anim_idx)
   {