Soft billboard puffs rise from a wide base and diffuse through a large, lazy curl field, expanding and thinning with age so the haze fills the whole frame. Move the pointer to stir the smoke — a swirl-plus-push force around the cursor carves moving voids and eddies into the volume. Alpha blending with a soft sprite disc lets overlapping puffs accumulate opacity into a believable hazy volume rather than glowing.