Demo https://output.jsbin.com/votuvi or even http://learnwebvr.xyz/upload/testing/
Exercise : clone that demo hide that little personage in a forest of tree, make it as realistic as possible.
Extra exercise : what's missing to make that scene much more realistic beside a nice smell of pine trees and glacial temperatures?
Curious about how meshes will be done in the near future? Check the Past VR painting workshop.
Done? Go back to learn more.