The cloud horizon flickered when the camera was far from the
deck because the regular raymarch steps aligned with the cloud
boundary. Two cheap fixes:
- Per-pixel jitter (hash21 of gl_FragCoord + uTime) shifts each
ray's start by up to one stepSize; the brain averages the
random offsets into a smooth edge
- Wider smoothstep (0.18 -> 0.24) softens the binary cloud/no-cloud
boundary the jitter is now dithering across
Richard Zink
65af0bf2f0