ADR-287: Update Emote schema with outcomes (Social Emotes)

Abstract

We are implementing a new feature named Social Emotes, which will allow multiple players to interact with this new kind of emote.

These new emotes will have a new property named outcomes, which lets authors define the animation to execute and specify whether it loops or not.

Context, Reach & Prioritization

• Why this matters: ADR-74 introduced emote versioning and extended the on-chain metadata with loop and additionalProperties (sound/geometry) while keeping richer data off-chain. Social Emotes require multiple animation outcomes for better player interaction, but we want to avoid bloating the on-chain metadata.
• Decision scope: Authoring tools, validators, and runtimes that read emote JSON; Collection contract metadata parsers.
• Urgency: Needed for the Social Emotes feature rollout while keeping backward compatibility with ADR-74 parsers.
• Terms:
  • Simple outcome (so): single deterministic outcome.
  • Multiple outcome (mo): several deterministic options.
  • Random outcome (ro): randomly chosen among candidates.

Solution Space Exploration

• All outcomes on-chain — Rejected. Bloats the metadata string, increases parsing complexity, and is brittle.
• Only a discriminator on-chain (chosen) — Minimal, backward compatible; rich data stays off-chain in JSON; aligns with ADR-74’s approach of small, append-only metadata changes.
• No on-chain hint — Rejected. Runtimes benefit from a cheap, parse-time discriminator to quickly branch behavior.

GLB Authoring: Naming Convention

To ensure consistency across exported GLB clips, we suggest the use of the following pattern: <Action>_(Start | Start_Prop | Avatar | Prop | AvatarOther)

Rules

• Action: Should be written in PascalCase (e.g., HighFive, WaveHello).
• Multiple words: Combine into PascalCase (no spaces or underscores).
• Suffix: Always appended with an underscore _, followed by one of the predefined roles (Start, Start_Prop, Avatar, Prop, AvatarOther).
• Compound suffixes: Use underscores between suffix parts (e.g., Start_Prop, AvatarOther).

Examples:

• HighFive_Start
• HighFive_Start_Prop
• HighFive_Avatar
• HighFive_Prop
• HighFive_AvatarOther

Rationale

• Improves readability, maintenance, and debugging through self-describing names.
• Decouples DCC tooling (e.g., Blender NLA tracks) from runtime configuration.
• Enables Builder to validate naming patterns on import and provide filtered dropdowns by action/step.

Specification

Versioned schema (off-chain)

export type ArmatureId = "Armature" | "Armature_Prop" | "Armature_Other"

export type EmoteClip = {
  animation: string // GLB clip name "HighFive_Avatar" (suggested, not enforced)
}

export type StartAnimation = {
  loop: boolean
  Armature: EmoteClip
  Armature_Prop?: EmoteClip
  audio?: string
}

export type OutcomeGroup = {
  title: string
  loop: boolean
  // Any subset of armatures; validated at runtime to ensure at least one
  clips: Partial<Record<ArmatureId, EmoteClip>>
  audio?: string
}

export type EmoteDataADR74 = {
  category: EmoteCategory
  representations: EmoteRepresentationADR74[]
  tags: string[]
  loop: boolean
  startAnimation?: StartAnimation
  randomizeOutcomes?: boolean
  outcomes?: OutcomeGroup[]
}

• Extends ADR-74 schema, adding properties startAnimation, randomizeOutcomes and outcomes optional to avoid churn.
• When one of those new properties is present, all of them MUST be present.
• Social emote SHOULD prefer the selected outcome’s loop if present.

Example (two-armature outcomes):

const emoteWithADR74Data = {
  // ...,
  emoteDataADR74: {
    // ...,
    startAnimation: {
      loop: true,
      Armature: {
        animation: "HighFive_Start"
      }
    },
    randomizeOutcomes: false,
    outcomes: [
      {
        title: "High Five",
        loop: false,
        clips: {
          Armature: {
            animation: "HighFive_Avatar"
          },
          Armature_Other: {
            animation: "HighFive_AvatarOther"
          }
        }
      }
    ]
  }
}

Outcome semantics

• so: outcomes.length === 1 always that outcome.
• mo: outcomes.length > 1 and no randomizeOutcomes: true deterministic selection policy (implementation-defined).
• ro: outcomes.length > 1 and randomizeOutcomes: true choose randomly among all outcomes.

Contract metadata (on-chain)

ADR-74 extended the metadata to include loop and then additionalProperties (sound/geometry) by appending fields on the right to avoid breaking older parsers. We follow the same pattern:

• ADR-74 (current)

  ${version}:${type}:${name}:${description}:${category}:${bodyShapeTypes}:${loop}:${additionalProperties}
  

• ADR-287 (append-only)

  ${version}:${type}:${name}:${description}:${category}:${bodyShapeTypes}:${loop}:${additionalProperties}:${outcomeType}
  

Where:

• outcomeType ∈ { so | mo | ro }
• Only outcomeType is stored on-chain. The full outcomes[] list remains off-chain in the emote JSON.

Deriving outcomeType from the schema

• If outcomes.length === 1: so
• Else if outcomes.length > 1 && randomizeOutcomes === true: ro
• Else: mo
• If outcomes is empty (legacy), treat as so using the default animation.

Validation

• Each outcome's armature MUST be a non-empty string.
• Within a given outcome, each armature MUST be unique across all clips (no duplicates).
• Each outcome's animation MUST be a non-empty string.
• Each outcome's loop MUST be a boolean.
• An emote MUST define at most 3 outcomes (hard limit to ensure manageable complexity).
• The on-chain outcomeType MUST be consistent with the off-chain outcomes[] derivation.
• additionalProperties continues to accept s | g | sg (sound/geometry) as per ADR-74.
• Older clients that parse up to additionalProperties MUST continue to function.

Examples

Random outcomes (off-chain)

const emoteWithADR74Data = {
  // ...,
  emoteDataADR74: {
    // ...,
    startAnimation: {
      loop: true,
      Armature: {
        animation: "Hug_Start"
      }
    },
    randomizeOutcomes: true,
    outcomes: [
      {
        title: "Hug Short",
        loop: false,
        clips: {
          Armature: {
            animation: "HugShort_Avatar"
          },
          Armature_Other: {
            animation: "HugShort_AvatarOther"
          }
        }
      },
      {
        title: "Hug Long",
        loop: false,
        clips: {
          Armature: {
            animation: "HugLong_Avatar"
          },
          Armature_Other: {
            animation: "HugLong_AvatarOther"
          }
        }
      }
    ]
  }
}
// outcomeType => "ro"

Resulting on-chain metadata (example)

${version}:${type}:${name}:${description}:${category}:${bodyShapeTypes}:${loop}:${additionalProperties}:ro

Note: The actual list of outcomes[] is not encoded on-chain.

References

• ADR-74: Add emote schema and versioning

License