Most 3D engines default to implementing a normal vector per vertex. In PolygonJS each face / polygon has a normal. This results in fewer normals and results in a flat-shaded, more geometric look.

Many years ago (around 1994) I wrote a simple filled-polygon 3D engine ... to learn about 3D graphics. Recently I wanted to add a graphics output to a microcontroller project I was working on, and I ...