@ferdinand
I'm showing an example with a curved surface composed of 8 zones.
Each zone is the union of several polygons with normals oriented in the same direction (represented by an arrow).
I think C4D should be able to identify this type of tiling and colorize these areas to highlight them.
Depending on the case, this tiling could be important, but most often, creators assemble the faces logically.
A window could then offer the option to select each tiling, in order to invert the normals with a single click.
A plugin could also do this kind of work, which would save creators time.
surface.jpg