Magical gene / fields and regions

Nightbloom Shroud

A marking said to fall on horses touched by fungal fae magic in old-growth forest: the crest and skull glow deep abyssal blue, and ribbons of gold-to-violet gill striping fan down the neck and barrel before fading out over the legs.

What it can come out as

Outcome	Carrying
Nightbloom Shroud	`Nbs/Nbs` · `Nbs/n`
Wild type	`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 10,000 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
`Nbs/Nbs`	Nightbloom Shroud	0.0005% — 1 in 200,000
`Nbs/n`	Nightbloom Shroud	0.0095% — 1 in 10,526
`n/n`	Wild type	99.99%

Its gene carrot

The file

common/src/main/resources/horsegenetics/genes/nightbloom_shroud.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.nightbloom_shroud`
Phase	magical — it adds signed colour in phase 3, after the pigment has resolved
Priority	284 — where it sits in the one `(priority, key)` paint order
Alleles	`Nbs` · `n`
Varies per horse	2 values drawn once off the expressing allele copy, so a foal that inherits the copy inherits the look
Built from	PARTS, PATH, RAMP, STROKES, TOWARD, emissive

Why it is built this way

Both layers hang off ONE five-point line running from the underline forward to the throat, inverted so coverage is zero on the line itself and grows away from it. The only difference between them is softness - ten body units for the gills, five for the mantle - which is what makes the mantle a tighter band along the topline inside the wider bloom.

The mantle's PARTS list names the head; its PATH mask's own parts list does not. A later mask outside its own parts is SKIPPED rather than zeroing, so the head takes the mantle whole while the body and neck take it graded. That is the one place in the format where a mask's parts list means 'where this term applies' rather than 'where the layer is'.

The legs are never named in either mask. The fade over them is the PATH softness running out before the leg boundary rather than a cut, which is why the marking stops rather than ends.

No hue knob: the blue-gold-violet is a specific bioluminescent identity, not a palette setting. The seed and the gill spacing vary the placement, and that is all a horse gets to choose.

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.

Nightbloom Shroud

The crest, poll and skull glow deep abyssal blue, and ribbons of gold-to-violet gill striping fan down the neck and barrel, dimming to the ordinary coat above the legs.

the gill striping — PARTS × PATH inverted × STROKES, painted with RAMP, and it glows
and the mantle over crest and skull — PARTS × PATH inverted, painted with TOWARD, and it glows

Wild type

Nothing.

Paints nothing.