Hey!
Yes they use bent normals for the lighting.
I tried to make the shape of the smoke very customizable.
Regarding how it acts/is emitted: there are a few properties you can change from the inspector with the custom tool script , but for more control it's basically a standard GPUParticles3D node with a basic ParticleProcessMaterial, so you can customize it like any other particle emitter.
Keep in mind that the effect has a second particle emitter too, which is used to emit transparent spheres to cast a shadow (that's what the "fake shadows" property in the custom tool script controls), so if you want to tweak the particles directly from the process material, I'd advise to copy the process material onto the shadowcaster particles as well so that the shadows follow the smoke!





























