# Day 10 - Matrices in 3D Graphics

## Matrix Overview

5 different martices for 3D graphics

- Identity
- Scale
- Multiply the identity diagonal by the scale factor

- Translation
- Move to 4x4, the last coumn is the trasnlation amount.

- Rotation
- 3 different matrices, look them up, not because you are lazy, but because you are precise
- Never track rotation as a sum of roations, store local x, y, and z axes in world space.

- Projection
- Divide x and y by z
- The way this is implemented is by breaking the w rule. Put 1 in the 3,4 matrix location. This will result in a non-1 w value. Divide by w. Away we go.

- Change of basis matrix