The following describes the properties for the items that appear on the Paint Tools tray (that is: Paint Brush, Projection, Airbrush, Pencil, and Erase Paint).
A directional light source simulates a very distant point light source. Its light rays are parallel to each other, as if emitted perpendicular from an infinitely large plane.
Let's talk about some important properties here.
The polygon is the basic building block of all 3d models. Here we discover its properties, like the face normal, which shows the direction the polygon is facing and it's three components the face, edge and vertex. Complicated objects are made of lots of polygons put together.