How often does your SketchUp slows down cause of complex models?
You would not believe in how many times lighter model may be, if you will make these simple corrections from the beginning.
Few people know, that almost all renderers and engines consider geometry as triangular polygons. You may not seen in, but your graphics card does. It is also vitally important for game developers.
Conditional division to Front and back Sides of the Face is necessary for different purposes: modeling automation(plug-ins), texturing, rendering and other engines. Do not be surprised when you`ll have any problems if you ignore the plane orientation.
1. The basic way to change face orientation is to klick on it with right mouse button, and find Reverse Faces in context menu.
2. Little more advanced way.
3. And this is a magical tool “ReverseOrientFaces” by Fredo.