/**
 * Procedural animation for part-composed (rig-less) models — characters kit-bashed from
 * primitives/`ModelPart`s with no skeleton or clips. Pure, deterministic curve sampling:
 * the same (time, speed, phase, flinch, death) input always yields the same pose, so
 * replays and multi-client renders stay in lockstep and the hot path allocates nothing
 * when an `out` pose is reused.
 */
/** Semantic motion role of one `ModelPart` in a part-composed character. */
export type PartRole = "head" | "arm.l" | "arm.r" | "leg.l" | "leg.r" | "tail" | "wing.l" | "wing.r";
/** Tuning for {@link samplePartPose}/{@link sampleBodyPose}; every field has a sensible default. */
export interface PartMotionParams {
    /** Full stride cycles per second at walking speed. Default 1.6. */
    strideHz?: number;
    /** Limb swing amplitude in radians at full walk. Default 0.7. */
    swingRad?: number;
    /** Body bob height in model units at full walk. Default 0.04. */
    bobAmp?: number;
    /** Idle sway/breathe amplitude in radians. Default 0.05. */
    swayRad?: number;
    /** Speed (world units/sec) treated as a full walk; swing/bob scale linearly below it. Default 2. */
    walkSpeed?: number;
    /** Backward flinch pitch in radians at flinch = 1. Default 0.35. */
    flinchRad?: number;
    /** Sideways topple roll in radians at death = 1. Default PI / 2. */
    toppleRad?: number;
    /**
     * Squash-and-stretch amplitude for soft characters (blobs, slimes): footfall squash while
     * walking, jelly breathe while idle, a squash pulse on flinch. Volume-conserving — the body
     * bulges horizontally as it compresses. Default 0 (rigid; scale stays exactly 1).
     */
    squashAmp?: number;
    /** How death reads: `"topple"` rolls sideways (default, hard characters); `"splat"` flattens the body out — right for blobs. */
    deathStyle?: "topple" | "splat";
}
/** Sampled offsets to add onto a part's authored transform (or the character root). `scale` is multiplicative (1 = unchanged). */
export interface PartPose {
    position: [number, number, number];
    rotation: [number, number, number];
    scale: [number, number, number];
}
/** Live signals a driver feeds the samplers each frame. All values are render-side only. */
export interface PartMotionInput {
    /** Seconds since the driver started (any monotonic clock). */
    timeSec: number;
    /** Horizontal speed in world units/sec (smoothed by the driver). */
    speed: number;
    /** Per-character phase offset in [0, 1) so crowds don't stride in sync — see {@link partMotionPhase}. */
    phase: number;
    /** Hit-flinch envelope in [0, 1]; the driver sets 1 on a hit and decays it. */
    flinch: number;
    /** Death ramp in [0, 1]; the driver eases it to 1 after the entity dies. */
    death: number;
}
/** A reusable identity pose (zero offsets, unit scale). */
export declare function createPartPose(): PartPose;
/**
 * Deterministic per-character stride phase in [0, 1) from an id (e.g. the entity instance id),
 * so a crowd of identical part-composed characters doesn't animate in lockstep.
 */
export declare function partMotionPhase(id: string): number;
/**
 * Sample the character-root pose: walk bob, idle breathe/sway, backward hit flinch, and death —
 * a sideways topple by default, or a flatten-out splat with `deathStyle: "splat"`. With
 * `squashAmp > 0` the body also squashes and stretches (footfall squash, jelly idle breathe,
 * flinch squash pulse), volume-conserving. A driver applies this to the group wrapping the
 * whole composition (base model plus parts) — limbs ride along, as they would on a real torso.
 *
 * @capability part-motion sample the root bob/sway/squash/flinch/death pose for a rig-less part-composed character
 */
export declare function sampleBodyPose(input: PartMotionInput, params?: PartMotionParams, out?: PartPose): PartPose;
/**
 * Sample one part's pose offset by role: counter-phase leg/arm swing driven by speed, a head
 * counter-sway, tail wag, and wing flap. Offsets are added onto the part's authored
 * position/rotation. Motion fades to zero as `death` ramps so the topple reads as one piece.
 *
 * @capability part-motion sample a limb/head/tail/wing pose offset for a role-tagged ModelPart
 */
export declare function samplePartPose(role: PartRole, input: PartMotionInput, params?: PartMotionParams, out?: PartPose): PartPose;