Simple geometric eye model

[alfredclwong]

Simple geometric eye model that includes rotation of the eye and allows for x,y,z offsets to sample the full eyebox.

Model includes Stiles Crawford https://royalsocietypublishing.org/doi/10.1098/rspb.2008.0712 shading effect when computing energy from beam being detected at the retina. Input is polygon that is the result of intersection between beam polygon and pupil polygon.

Use Stoke's theorem to convert the area integral across the intersection polygon into a line integral across the edges of the polygon. Or use numerical integration library.

[alfredclwong]

Opened branch paraxial-eye for this. Currently requires eye-data branch to run scratch.jl.

@BrianGun regarding rotation and x,y,z offsets, can this not be managed by applying transforms to root node of the eye assembly?

[BrianGun]

@alfredclwong yes applying transforms to root node should be fine.