Brightens or darkens at regular intervals.
Object: poles or sphere
Number of edge colors: 8 * 2 (Black edges included)

Made with GLSL and p5.js

***It may not work properly on some mobile devices that do not support
high precision float.***

Key Input:
s: screen capture (.png)
f: Fix the viewpoint in the center. (ON/OFF)
g: Apply gamma correction. (ON/OFF)