by Patricio Gonzalez Vivo and Jen Lowe
- https://github.com/danilw/godot-utils-and-other
- https://danilw.itch.io/particle-effects-godot3
- https://github.com/danilw/godot-utils-and-other/tree/master/particle_system_effects_Godot3
- https://www.shadertoy.com/view/wt2fWw
- https://docs.godotengine.org/en/latest/tutorials/shaders/index.html
- https://docs.godotengine.org/en/latest/tutorials/shaders/converting_glsl_to_godot_shaders.html
- https://docs.godotengine.org/en/3.5/tutorials/shaders/index.html
- https://docs.godotengine.org/en/3.5/tutorials/shaders/converting_glsl_to_godot_shaders.html