Vertices and triangles
All 3D models consist of a collection of points in space called vertices. These vertices (singular: vertex) define the shape of the model when combined. Each vertex is a coordinate in space, represented in vector form. They can, however, also contain further information, such as the following:
- Color
- Normal
- Texture coordinates
- Anything else you need to draw the model
These vertices are used by the GPU to draw the model; however, the GPU by itself has no way of understanding how they relate to each other, and how to draw the correct model. This is resolved by arranging vertices into the most basic shape possible: a triangle. If you consider that one vertex alone as a point, which along with a second forms a line, then a third vertex creates a triangle, which is the simplest polygon you can create. The GPU can then draw these triangles by taking the vertices, three at a time, and using those values to generate an area to draw.
A model created in a 3D editing program can have...
