Morph power and attribute data

Morph powers select a form and its actions; attribute profiles modify the wearer during chosen phases. This page defines the authored fields and reload behaviour, with runtime extension contracts linked separately.

Where the files live

Morph powers use data/<namespace>/powers/<path>.json; attribute profiles use data/<namespace>/morph_attributes/<path>.json. The relative path defines each resource ID. Powers must also be granted through the pack’s origin or other power-grant mechanism. The power’s id chooses an already registered skill execution; writing a new identifier does not create that execution.

Player-control forms include this mod’s base NPC family and entity types in isekaiexpansion:morph_player_rigs. Those forms retain player controls and replace both authored mouse abilities with isekaiexpansion:none. Only opt a third-party humanoid into that tag when its renderer supports the player-rig contract.

Minimal example

To override the existing fox power, place this at data/isekaiorigins/powers/kitsune_active_fox_form.json. It uses the already registered execution and ability IDs; this file alone does not grant the power.

{
  "type": "isekaiorigins:morphing_skill",
  "id": "isekaiexpansion:kitsune_active_fox_form",
  "meta": {
    "max_level": 1,
    "cooldown": "240",
    "energy": "0"
  },
  "entity_type": "minecraft:fox",
  "primary_ability": "isekaiexpansion:entity_primary",
  "secondary_ability": "isekaiexpansion:kitsune_fox_pounce",
  "transition_ticks": 18
}

An independent profile at data/example/morph_attributes/fox_speed.json adds a speed modifier to players in the active fox form:

{
  "forms": [
    "minecraft:fox"
  ],
  "phases": [
    "ACTIVE"
  ],
  "modifiers": [
    {
      "attribute": "minecraft:generic.movement_speed",
      "operation": "multiply_total",
      "value": 0.2,
      "scale": {
        "attribute": "isekaiexpansion:dexterity",
        "factor": 0.002,
        "max": 0.1
      }
    }
  ]
}

For this example the modifier amount is 0.2 + min(0.1, dexterity × 0.002). The upper clamp applies only to the scaled term. This profile stacks with the shipped fox profile; use the shipped profile’s resource ID if replacement is intended.

Fields

Morph power

The morph power fixes its side to active; it has no authorable side field.

A positive duration_ticks makes the form timed, the same way a talisman form is timed. The clock starts once the form finishes entering, so 1200 gives 1200 ticks (60 seconds) in the settled form and the transitions run outside it. When the time runs out the form returns on its own and the power’s cooldown starts, as after a manual return. A player with no room to stand stays in the form until there is room, and is told so once. The morph panel’s bar drains while a timed form runs, and the skill screen lists the duration.

Level metadata

Each series is a slash-delimited string containing either one finite number for every level or exactly max_level numbers. "10/20/30" has 3 entries; blank entries, nonfinite values and the wrong count fail. Values are trimmed before numeric parsing. Lookups clamp the requested level into the supported range. Additional valid keys are retained, but only a consuming handler gives them behaviour.

Core ability metadata uses these optional series:

Integer lookups use the handler fallback for fractional or out-of-int-range values. Accepted ability cooldowns clamp negative values to 0. Other custom series only require finite values at parse time; choose physically meaningful values for velocity and damage.

Eligibility and trigger effects

For regular isekaiorigins:triggerable_skill and isekaiorigins:ultimate_skill, omitting morph_able permits only normal form. An empty object permits normal form and every active morph; an explicit entity_types list restricts active forms. Ordinary skills remain blocked during entry/exit regardless of that policy. The morphing subtype stays eligible so its owning skill can request a return, but other checks can still reject the request. A return pressed during the settle lock is refused like any power on cooldown, so the earliest return comes 60 ticks (3 seconds) after entry.

Sound, animation, effect and action restrictions run after the execution accepts. For effect asset and builder details, see Effekseer integration.

Attribute profile

The amount is value + clamp(source_attribute × factor + offset, min, max). Scaling reads the player’s current effective attribute, including currently installed modifiers. It is evaluated before old morph modifiers are removed, so a source affected by another morph modifier can feed back into the next refresh. This is not a dependency graph or a continuously recalculated formula.

All matching profiles contribute temporary player modifiers. Stable modifier identity derives from profile ID and array index, so identical attribute entries at different indices remain separate contributions. Priority orders resolution; it does not suppress other profiles. Attributes missing from the player are skipped.

Validation

Attribute roots must be objects. Selectors accept a primitive converted to text or an array of text-convertible entries; object/null shapes fail. Use strings deliberately: numeric primitives can become valid-looking identifiers. Invalid phases, operations, required IDs or modifier objects reject the entire profile. Unknown fields are ignored. A failed profile is logged and skipped while the registry is replaced by the successfully parsed set; its previous value is not retained.

An attribute profile requires both a nonempty selector set and a nonempty modifier list. Valid but unmatched forms/tags simply produce no modifiers. Attribute numeric fields have no explicit finite-value or gameplay-range validation.

Power construction rejects invalid category or metadata values and requires the fields marked above. Entity and ability availability is resolved later. A morph needs a living target, free space for its dimensions and a player who is not riding. Returning requires standing-player clearance. A rejected morph execution does not spend its trigger cost or apply its trigger effects. A successful return can use the same energy cost as entry; zero-cost return is not implied.

Entity-specific ability overrides take precedence over authored IDs. The built-in warden and witch overrides choose their respective primary and secondary actions; isekaiexpansion:none in a power does not suppress an installed entity override. Dedicated variants can own a form’s texture and bypass generic morph texture overrides.

Reloading

Attribute profiles reload with server data packs. On a successful reload, online players’ temporary modifiers are refreshed; phase changes, join and respawn also refresh them. Source-attribute changes alone do not trigger a refresh, and the component does not recalculate scaling every tick. Leaving the form removes its applied modifiers.

Power definitions follow the installed power loader. The active morph stores its resolved form and ability IDs; do not assume editing a power rewrites an already running form. Re-enter after reloading when checking changes.

Textures are client resources. Without skin_id, the candidate is assets/isekaiexpansion/textures/morphs/entities/<entity-namespace>/<entity-path>.png; with it, the candidate is assets/isekaiexpansion/textures/morphs/skins/<skin-namespace>/<skin-path>.png. A missing candidate leaves normal renderer texturing in place. Reload client resources after changing PNGs; JSON does not define native form variants.

Related

• Humanoid preset data
• Attributes and effects
• Effekseer integration