discharge

Light escaping a piece of high-voltage hardware — the same picture in the three places Station Nine shows what is happening inside it, so it is one shader rather than three.

• the seams of the hero transformer as it saturates and the core light gets out past the casing,
• the current tracking crawling an insulator disc stack in blue filaments,
• the corona sleeve creeping along a bus conductor.

The card's uv.y runs along whatever the filaments crawl and uv.x across it, and both axes carry a soft edge so a sleeve wrapped on a cylinder or a band laid on a casing never shows its own border.

glow is the body light and filament the threads over it; crawl is how fast they travel, filament_scale how fine they are, sharpness how thin each thread is, and flicker how hard the whole thing stutters. color is the filament's colour and hot what it goes to at full brightness. seed puts two cards carrying the same material out of step with each other.

Draw it with an additive, cull: none, depth_write: false material.