cm_steam

# chimney_smoke Coal smoke for Smog's chimney pots: soft, sooty grey-green billows that leave the pot, climb ~9 m, swell to ~6 m across, drift east on the wind and thin away over ~15 s, their insides slowly churning. Lit per vertex by the ambient and the moon (brighter when the moon is behind the plume) and in the fragment by nearby gas lamps. Alpha-blended, no depth write. One mesh (`art.fx.smoke_puffs`, 26 puff cards spread over the life cycle) is one plume; every entity wearing it is a chimney, its origin the pot and its x scale the plume size, so a street of chimneys is one instanced draw. Each pot gets its own phase and life from its position. Material: `art.fx.chimney_smoke`.