This idea popped into my brain out of nowhere a few days ago. There is now a render setting to highlight upward-facing triangles. This can be nice if you want your player to only be able to walk on relatively smooth terrain, and would like to be able to tell in the editor if your terrain is “smooth” or not.

semi-related but dither effects are fairly cool.

Changes in 2022.0.5

• Added an option to highlight upward-facing triangles to make it easier to create smooth surfaces for roads, etc You can define the threshold for highlighting upward-facing triangles, in terms of degrees away from the up vector