Function cameraAim

cameraAim(eye, target, up, dst?): Mat4
Computes a 4-by-4 camera aim transformation.

This is a matrix which positions an object aiming down negative Z. toward the target.

Note: this is the inverse of lookAt
Parameters
- eye: Vec3
  The position of the object.
- target: Vec3
  The position meant to be aimed at.
- up: Vec3
  A vector pointing up.
- Optional dst: Mat4
  matrix to hold result. If not passed a new one is created.
Returns Mat4
The aim matrix.