Revit's surface patterns can't be used on toposurfaces (they're unsupported), neither can they be used on shape-edited floors, because they distort badly.
Paving patterns can't therefore be drawn in Revit, without the workaround of duplicating floor objects (to have a 2D version used solely for the hatch pattern). This is a serious time-eater and discourages the use of BIM for site modelling and landscape drawings.
If you doubt that surface patterns distort, then watch the embedded screencast video (only 23 seconds!) The floor has been had 'Modify Sub-Elements' applied, to shape edit the corner levels in a very simple way - a single fall gradient. When the boundary is amended, the surface pattern goes haywire!
Idea: Fix the hatch patterns!