you basically render the cubemap onto a sphere, into the environment map, and now you can rotate the sphere.
in vanilla you would use a cubecam, render that sphere with backfaces, the cube texture goes into scene.background and scene.environment.
you basically render the cubemap onto a sphere, into the environment map, and now you can rotate the sphere.
in vanilla you would use a cubecam, render that sphere with backfaces, the cube texture goes into scene.background and scene.environment.