Nymphaline

What it can come out as

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.

Its gene carrot

The file

common/src/main/resources/horsegenetics/genes/nymphaline.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.

Why it is built this way

The source was an SVG: eight posterised colour layers traced off a close photograph of a green-and-pink wing, about 300 KB of path data. That is exactly the traced photograph the SVG mask's point ceiling exists to keep out, and it is also the wrong shape of thing - the picture is a patch of membrane, not an outline, so there was nothing to place. It is rebuilt here as a rule.

Reading of the source, in the order the layers restate it: a thick dark spar down one edge; veins radiating off it and widening as they travel; a pale cream ridge running alongside every vein on both sides; rose membrane between them in two values that pool into each other rather than banding; and a darker margin at the far edge where the venation breaks down into a fine net of small cells.

FAN is the whole of the radiating half, and the origin is the number that decides whether it works. Put the pivot above the back and the barrel subtends about 74 degrees of it, so a spacing wide enough to give veins a texel of width leaves three of them on the whole flank. The pivot therefore sits ON the flank, at the point of the shoulder (u 0.68, v 0.58), where the barrel subtends nearer 100 degrees and a spacing of 0.29 puts six veins across it at about 0.75 body units wide out at mid-flank. Moving the root is the first thing to check if the vein count comes out wrong.

spacing is an angle, so vein width scales with distance from the root: about a third of a unit at r=5 and nearly two units at the tail end. That is what a wing does, and it is also why inner is 3.5 - inside that radius the veins are under a texel and would break into stipple, and the spar layer covers the root anyway.

The cream ridge is two FAN masks on one origin and one spacing, the narrow one inverted: a wide bar minus the vein core is a band either side of it. They must stay on the same knobs or the ridge walks off the vein.

The lower-rear net is CRACKLE rather than a finer FAN, and deliberately: a second fan fine enough to read as secondary venation comes out under half a texel wide at every radius on the barrel. CRACKLE with vertexWeight up pools where channels meet and thins between them, which is what a vein network does and what the source shows in that corner.

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.

Nymphaline

The flank is a butterfly wing: rose membrane cut into cells by dark green veins that radiate from a heavy spar along the back, every vein edged in cream, the venation breaking down into a fine dark net over the lower hindquarter.

Layer order is load-bearing at the veins: the cream ridge is painted before the vein core, so the vein sits down the middle of its own highlight. Swapping them puts a green line beside a cream one.

1. the membrane - two roses pooling into each other — PARTS, painted with RAMP
2. the margin darkening down and back — AXIS inverted × AXIS × NOISE, painted with TOWARD
3. the fine net where the venation breaks down — CRACKLE × AXIS inverted × AXIS, painted with TOWARD
4. the cream ridge either side of every vein — FAN × FAN inverted, painted with TOWARD
5. the veins — FAN, painted with TOWARD
6. cream running under the spar — AXIS, painted with TOWARD
7. the spar along the topline — AXIS, painted with TOWARD

Frosted wing

The same venation with the pigment gone out of it - a bone-white membrane veined in grey-green, like a wing held up to the light.

The recessive half of the usual pair. Same masks and the same knobs, so a horse that changes form between generations keeps its own venation; only the four colours move.

1. the membrane, drained — PARTS, painted with RAMP
2. the margin darkening down and back — AXIS inverted × AXIS × NOISE, painted with TOWARD
3. the fine net where the venation breaks down — CRACKLE × AXIS inverted × AXIS, painted with TOWARD
4. the pale ridge either side of every vein — FAN × FAN inverted, painted with TOWARD
5. the veins — FAN, painted with TOWARD
6. the spar along the topline — AXIS, painted with TOWARD

Wild type

No wing.

Paints nothing.