Waterborn

The effects

The behaviour half is an effects block — three of the five effect verbs. common/ parses it; the NeoForge translator runs it.

"effects": [
  { "type": "traversal", "flag": "walk_on_water", "when": { "flag": "adult" } },
  {
    "type": "emitter", "kind": "particle", "shape": "trail", "anchor": "feet",
    "trigger": { "on_move": {} },
    "particle": "minecraft:dust", "color": "#1ec8ff", "chance": 0.7
  },
  {
    "type": "yield",
    "trigger": { "on_interact": "minecraft:bucket" },
    "consumes": "minecraft:bucket", "produces": "minecraft:water_bucket",
    "cooldown": 2400,
    "when": { "all": [ { "flag": "sex_female" }, { "flag": "tamed" } ] }
  }
]

walk_on_water

An adult Waterborn horse rides at the surface instead of sinking — the when: { flag: adult } gate means a foal wades normally. This one is an approximation: the translator adds buoyancy and clears the fall each tick, it does not build a solid collision plane, so the feel (edges, bobbing, a rider’s head dipping) is the thing to watch in-game.

the dust trail

A minecraft:dust particle in #1ec8ff at the hooves, fired on_move — only while the horse is moving on the ground — with a per-tick chance of 0.7. Nothing while standing or swimming. Confirmed working 2026-09-02.

the mare milking

Right-click a tamed mare with an empty bucket and it becomes a water bucket; the interaction is eaten so no mount happens, and a cooldown of 2400 ticks (2 minutes) throttles it. The when is sex_female and tamed, so a stallion or an untamed mare just gets mounted as usual. A non-creative player’s bucket is consumed.

Gene key

horsegenetics.waterborn

Alleles

Wtb n

Outcomes

wild, waterborn

Shows when

Wtb/n, Wtb/Wtb

Default allele

n

Wild frequency

1 in 90 per allele → ~1 wild horse in 45 shows it

Founder draws

1 × nextFloat()

Deterministic

no when expressed — the stripe field varies per horse

Epigenetic draws

1 long (stripe seed) + 1 nextFloat (stripe spacing), off the Wtb copy

Priority

215 — a data-driven magical gene, slots before Test in magicalOrder()

Stripe colour

#1ec8ff (30, 200, 255), 92% of the way there

Effects

traversal walk_on_water, emitter dust trail, yield mare→water bucket

The coat: neon streaks in the mane and tail

The visual half is one ordinary magical coat layer: a STRIPES mask restricted to the HAIR parts (mane + tail) crossed with a TOWARD op that walks each covered texel 92% of the way to #1ec8ff.

{
  "name": "neon blue stripes down the mane and tail",
  "masks": [
    { "type": "STRIPES", "parts": [ "HAIR" ], "seed": "$stripeSeed",
      "spacing": "$stripeSpacing", "duty": 0.4, "warp": 0.8 }
  ],
  "op": { "type": "TOWARD", "color": "#1ec8ff", "strength": 92, "opacity": 100 }
}

TOWARD rather than TINT for the same reason mane colour uses it: it reads what each strand currently looks like and steps it toward the target, so the mane keeps its light and dark instead of turning into a flat slab, and it reads the same on a black, a chestnut or a cremello. opacity: 100 means the streaks also show on a dominant-white horse.

Two knobs make the pattern per-horse, so no two Waterborn manes are identical:

Because a knob is in play, a visible Waterborn is non-deterministic: each horse bakes its own texture, keyed by the seed on the Wtb copy it carries, and a foal that inherits that copy inherits the exact streak pattern.

The first gene that ships as a file

Every other gene is either a hand-written Java class or a file the player drops in themselves. Waterborn ships inside the mod: a classpath index (neoforge-26.1.2/src/main/resources/horsegenetics/genes/index.json) that GeneSpecLoader.fromClasspath() registers from the mod constructor. Suntouched was added beside it the same way. It was done to make the effects work testable without a config drop, and it breaks the standing “no gene ships by default” rule on purpose — with the two shipped genes:

• the in-game genotype code is 13 segments, and shorter saved horses will not load;
• the GenotypeCatalog count is roughly 4× its no-gene size (each shipped DOMINANT two-allele gene doubles it);
• :common:test is unaffected — that index is in the NeoForge module’s resources, not on the common test classpath, so the golden test and the 11-built-in count still hold.

To turn Waterborn off, drop it from index.json and delete the file. The horse dimension is due for an overhaul regardless.

Not modelled yet

• One stripe colour and one strength; no per-horse colour variation. An allelic series (teal / indigo / white-water) would make it the first shipped data-driven gene with more than two alleles.
• The walk_on_lava sibling flag exists in the format but the translator does not wire it; an ember-born counterpart is the obvious pair.
• The gene creator cannot edit an effects block yet — Waterborn’s was hand-written.