Game Development Reference
In-Depth Information
ordinate in space, represented in vector form. They can, however, also contain fur-
ther 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 pos-
sible: 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 poly-
gon 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 thousands of these vertices, all
forming triangles that define the final shape. The following diagram shows one such
instance:
