You can use the advanced search syntax described in the SKNode documentation, under Advanced Searches.
This will search the entire node tree recursively for a node named "SPHERE2", starting from the root node:
SKNode* sphere2 = [root childNodeWithName:@"//SPHERE2"];
If you know the path to a specific node, you can also use that quite easily:
SKNode* triangle3 = [root childNodeWithName:@"/CUBE3/SPHERE2/TRIANGLE3"];
It should be noted if you need those nodes often, you should cache them in a __weak
ivar or weak
property because searching nodes by name takes a little while.