//5 min

Vertical Melt: Pixels That Drip

Pixel Sort's patient sibling. A guide to Yan's Vertical Melt — what it does, when to use it, and how to keep it from becoming mud.

#tutorial#vertical-melt

> The Short Answer

Vertical Melt scans every column top to bottom and overwrites each pixel above the melt threshold with the pixel directly above it, so bright regions inherit downward until something darker breaks the chain. The melt threshold is the only knob that really matters: 120-170 melts highlights only and is the most balanced, 200+ drips just the brightest neon or sun glare, and 50-100 melts mid-tones too and usually turns the frame to mud. It differs from Pixel Sort in kind: Pixel Sort rearranges a whole row, Vertical Melt extends selected pixels downward.

What Vertical Melt Does

For each column, Yan finds pixels above the melt threshold and stretches them downward. Bright pixels leave trails. Dark pixels stay put.

The result looks like the image is melting — wet paint, sunlight bleeding, a candle losing its top.

Vertical Melt Algorithm Diagram

How It's Different from Pixel Sort

Pixel Sort rearranges an entire row. Vertical Melt extends selected pixels downward.

  • Pixel Sort: structural, like cards reshuffled. You can try horizontal and vertical column sorting directly in our Pixel Sorting Online browser tool.
  • Vertical Melt: gravitational, like fluid pulled down.

Pixel Sort is louder. Vertical Melt is moodier. Use the right one.

Parameters

Melt Threshold (0–255)
The only knob that matters for the output.

  • Low (50–100): even mid-tones melt. Heavy effect, often becomes mud.
  • Medium (120–170): only highlights melt. Most balanced. Default sits here.
  • High (200+): only the brightest pixels drip. Subtle, surgical.

The algorithm scans every column top-to-bottom. Any pixel above the threshold gets overwritten by the pixel directly above it. So once a bright region starts melting, the entire column below it inherits that bright color, all the way down — until something darker breaks the chain.

Good Subjects

  • Sky and clouds: melts beautifully, softens the horizon
  • Neon signs at night: lights drip down. Hong Kong / Blade Runner vibe.
  • Portraits with backlight: hair dissolves into background
  • Anything with a strong horizon: the boundary becomes the drip line

What to Avoid

  • Already-bright images: everything melts, becomes mud
  • Detailed foregrounds you want to keep: raise the threshold above the foreground's brightness

Recipes

Wet Window

  • Threshold ~150
  • Bright sky drips into the rest of the photo
  • Subtle, atmospheric

Neon Cascade

  • Threshold ~210
  • Only the very brightest pixels (neon, streetlights, sun glare) drip
  • Everything dimmer stays sharp

Painted Subject

  • Threshold ~100
  • Heavy melt, makes the photo look hand-painted with very runny paint

Combinations

  • Melt + RGB Shift: chromatic drips. Hallucinatory.
  • Melt + CRT: dripping broadcast. Looks like the analog TV is dying.
  • Melt + Pixel Sort: two kinds of distortion fighting. Use Melt first, or experiment with vertical pixel runs in Pixel Sorting Online and the full Texture Studio.

The Idea

Photos pretend gravity stops at the shutter. Vertical Melt re-enables it.

> Frequently Asked

How is Vertical Melt different from Pixel Sort?
Pixel Sort rearranges the pixels already inside a row, like reshuffling cards. Vertical Melt extends selected bright pixels downward through the column, like fluid pulled by gravity. Pixel Sort is structural and loud; Vertical Melt is gravitational and moodier.
What melt threshold should I use?
120-170 for a balanced result where only highlights melt. Go above 200 when you want only the very brightest points, such as neon or streetlights, to drip while everything else stays sharp. Below 100 the mid-tones melt too, which is usually too much.
Why does my melted image turn to mud?
Either the threshold is too low or the photo is already bright overall. When most pixels clear the threshold, every column melts at once and there is nothing sharp left to contrast against. Raise the threshold above the brightness of whatever you want to keep.