When and when not to use world space (final position.)

[james adamson]

A basic question but I must ask it. Does world position refer to actual final position. i.e after any compute normals and when no more displacement is to be done.
For instance, on a transform input on a cloud density fractal? And could someone please explain the other option. Use undisplaced space (position in geometry.)
What would the practical use be for this option.
Ta.
James.

[WAS]

Are you by chance referring to the World Space (final positions) that were in my cloud file? This is so that if move textures with clouds is active, and you're animating, the terrain masks and altitude offsets don't also move with the clouds. They remain in their final position.