I have followed the tutorial below to build a Vision Pro app.
https://developer.apple.com/tutorials/develop-in-swift/create-3d-models-in-the-shared-space
When I run the app in Vision Pro Simulator, the models are much darker than the sample in the last picture of the above link.
How to fix the problem? Do I need to create lights to illuminate the model? It was not mentioned in the tutorial.