Height-graded curtain palette: first = bright lower rim, middle = mid-ray, last = faint ray tips (2-5 stops)

Night-sky base color behind the curtains

Background opacity; 0 floats the aurora transparently over the host section and hides the stars

Overall motion rate; low values give the slow, majestic drift of a real aurora

Ray and rim diffusion: low = sharp needle striations and crisp lower border, high = dreamy glow

Number of overlapping curtain layers at different depths and brightness

Tilt of the arc across the sky in degrees

Undulation depth of the arc's serpentine sweep

Feature density: higher = finer striations and tighter waves

Striation punch: higher carves brighter filaments against darker gaps

Film grain amount layered over the banding dither

Vertical position of the bright arc (0 = bottom, 1 = top); rays rise above it, soft glow bleeds below