Base Terrain Geo 

Geo from Camera

Trail from Camera movement ( 240 frames-> 4 trails )  

Boolean Intersect 

Boolean intersect result

Rain emitter geo from camera

boolean intersect between rain emitter geo and terrain

POP network > Emitter source + VDB terrain (collision )  

Blue = Source Pts ( with different seed each frame )
White = Initial POP stream
Red = "Splash" particles, on collision with ground

Each point has a random fitted fuel and temperature value
VDB from particles ( fuel, temperature and vel )

POPs as source for the new H18 Sparse Pyro Solver

- div size 0.005
- 4 substeps