In our daily life it is not hard to imagine the third dimension, as we are part of it all the time. On a computer screen, 3D is different because a screen is 2D only. Let's get a little more familiar with the illusion of the third dimension on a two-dimensional screen.
In 3D geometry, every object consists of a group of vertices, also known as verts (singular: vertex). A vertex is a point in 3D space. When you define the position of a sprite in Flash, you set it on two axes, the x- and y-axis. A vertex has a third coordinate, set on the z-axis. The order of the coordinates in 3D is always x, y, z.
Vertices form triangles, also known as faces, or triangle faces, so every triangle is made of three vertices. Other 3D programs sometimes enable you to create faces that are made up of four vertices, also known as quad faces, but Papervision3D knows only triangle faces. The vertices define the shape of the triangle and because they have x, y,...