Tron

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 3,571 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/tron.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 halo is lit now, at a flat 0.25, and the tube carries the gene's dial ('burn'). That is the whole of what a neon tube does and the gene could not say it before: the glass burns, the panel beside it catches some of that, and the catch falls off with distance - which here is free, because a glow is scaled by its layer's coverage and the halo's EDGE mask already fades. The halo's level is a constant rather than a fraction of the tube's because the format has no arithmetic; keeping it below the dial's floor of 0.4 means the tube is the brighter of the two on every horse.

All three expressions get the same treatment, including 'both', where the solid tube and the gradient tube are separate layers - they light independently and take the brighter where they overlap, which is what CoatOverlay does with two glows on one texel.

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.

Solid outline

One neon colour, run along every edge of every box the horse is made of, with a weaker halo bleeding off it onto the panel either side. The colour is the horse's own and is inherited with the copy, so a line of Tron horses keeps its colour and a cross with another one does not average them - the foal gets one parent's tube or the other's. The tube renders full-bright, so it holds its colour in a dark stable.

1. the halo the tube throws onto the panel around it — EDGE, painted with TOWARD, and it glows at 25%
2. the lit tube itself, along every edge of every box — EDGE, painted with TOWARD, and it glows, by an amount that varies per horse

Gradient outline

The same tube, carrying a hue ramp instead of a colour: it starts at the horse's own hue at the tail and travels five sixths of the way round the wheel by the nose, so the line changes colour along the horse rather than along its own length. Which end of the spectrum a horse starts at is the epigenetic value, exactly as on the solid form.

1. the halo the tube throws onto the panel around it — EDGE, painted with RAMP, and it glows at 25%
2. the lit tube, running the whole circle of the wheel tail to nose — EDGE, painted with RAMP, and it glows, by an amount that varies per horse

Solid and gradient

One copy of each. Neither is dominant to the other, so the horse gets both tubes laid on the same edges - the ramp over the solid core, which reads as a brighter, harder line than either allele draws alone.

1. the halo the tube throws onto the panel around it — EDGE, painted with TOWARD, and it glows at 25%
2. the lit tube itself, along every edge of every box — EDGE, painted with TOWARD, and it glows, by an amount that varies per horse
3. the halo the tube throws onto the panel around it — EDGE, painted with RAMP, and it glows at 25%
4. the lit tube, running the whole circle of the wheel tail to nose — EDGE, painted with RAMP, and it glows, by an amount that varies per horse

Wild type

No outline.

Paints nothing.