Magical gene / colour modifiers

Nacre

The coat breaks into hard-edged plates like a cracked shell, each one paler at its gold seams and richer toward its middle.

What it can come out as

Outcome	Carrying
Nacre, opal	`Nco/Nco` · `Nco/Ncg` · `Nco/n`
Nacre, glaze	`Ncg/Ncg`
Wild type	`Ncg/n` · `n/n`

How each one is actually drawn - region by region, and the layers it is built from - is on the coding tab.

Crossing two of them

Finding one

About 1 in 1,786 wild horses is born showing this. That is the whole of the supply: catch one, or make one with the carrot below. Breeds set their own pools and a breed built around this gene will carry it far more often than the wild population does.

Wild pair	Shows as	How often
`Nco/Nco`	Nacre, opal	0.002% — 1 in 50,000
`Nco/Ncg`	Nacre, opal	0.008% — 1 in 12,500
`Nco/n`	Nacre, opal	0.038% — 1 in 2,632
`Ncg/Ncg`	Nacre, glaze	0.008% — 1 in 12,500
`n/n`	Wild type	99.944%

Its gene carrot

The file

common/src/main/resources/horsegenetics/genes/nacre.json — a data-driven gene, not a Java class. It is listed in the index.json beside it and registered by Genes' class initialiser at startup.

Key	`horsegenetics.nacre`
Phase	magical — it adds signed colour in phase 3, after the pigment has resolved
Priority	436 — where it sits in the one `(priority, key)` paint order
Alleles	`Nco` · `Ncg` · `n`
Varies per horse	6 values drawn once off the expressing allele copy, so a foal that inherits the copy inherits the look
Built from	CRACKLE, PARTS, RAMP, TOWARD

Why it is built this way

The plate colour, the darkening at its middle and the seam between plates are three readings of ONE tessellation on one seed and one scale. The middle is CRACKLE measuring from the centre of the cell out rather than from its wall in - the only per-cell radial coordinate in the vocabulary that a crackle outline is guaranteed concentric with, and the reason the core cannot slide off the plate it belongs to.

Hard walls between colours are usually the thing to avoid, and here they are the point: a plate edge is meant to be sharp, because that is exactly where the gold seam is drawn on top of it.

Per-dose on the core layer, not on the plates: one copy of the pale form darkens the middles at a little over half strength, two copies take them all the way. The plates themselves are the same either way, so a heterozygote reads as the same shell with less depth in it.

What it paints

Each outcome, described the way the gene file describes it, and then the layers that draw it in the order they are painted. The prose is the part a reader checks a bake against; the list underneath is what the engine actually did.

Nacre, opal

Pale irregular plates of blush pink and sky blue, each deepening toward a flamingo-pink heart, all of it seamed with fine cracks of pale gold.

the plates — PARTS × CRACKLE, painted with RAMP
deepening toward each plate's middle — PARTS × CRACKLE × CRACKLE inverted, painted with TOWARD
and the gold seam between them — PARTS × CRACKLE inverted, painted with TOWARD

Nacre, glaze

The same cracked plating, but every plate and its darkened middle run in one rich colour instead of pastel on pastel - a horse that looks poured rather than shelled.

the plates — PARTS × CRACKLE, painted with RAMP
deepening toward each plate's middle — PARTS × CRACKLE × CRACKLE inverted, painted with TOWARD
and the gold seam between them — PARTS × CRACKLE inverted, painted with TOWARD

Wild type

Nothing.

Paints nothing.