still_vapour_warm

# still_haze A sleeve of vapour standing in the still. The shell is invisible where the camera looks through it square on and brightest where the view grazes it, which is what an open tube of air does — so a plain cylinder reads as a column of light. It draws additively, writes no depth, and fades at both ends of its own `uv.y`, so a sleeve never terminates on a hard ring. A slow noise churn drifts upward with `input.time`.