I am using the maxwell render plugin for Cinema4D. I have tagged a mesh surface with grass but the grass is upside down. It is on the underside of the mesh. How do you invert the face? Any help would be much appreciated.
I'm not really familiar with Maxwell but it could be that your surface normals are pointing in the wrong direction. Selected polygons should be tinted to show which direction the normal is facing. The defaults are orange (normal pointing toward you) and blue (normal pointing away). If you need to reverse them there is a command to do so (default shortcut: U-R).