RGB or RGBA color, or an index into graphics/rendering/settings/runtime-settings!RuntimeSettings.colorPalette.
A class with constructor
new Droplet(from: vec2, to: vec2, fromRadius: number, toRadius: number).
from and to are endpoint positions in world coordinates; fromRadius and
toRadius are the radii at those endpoints in world units.
Pass the class's static descriptor to compile!compile, then pass instances to
graphics/rendering/renderer/renderer!Renderer.addDrawable.
Creates a drawable droplet class with a shared color.