You can still use the #Preview macro, but .previewLayout will be ignored. Use #Preview("Title", traits: .sizeThatFitsLayout) instead.

Thanks for your reply. My goal is to visit a real place that inspires an immersive space, say a place on the beach. I want to take photos, videos, photogrammetry scans, etc. and bring them back and create an immersive space that approximates the location. How do I get the far distant skybox photos separate from the foreground? What elements should I create procedural textures for vs. using scanned textures? The samples that I've seen start with created assets. I want to know how to make those.