/**
 * Constrain an uphill heightfield step by its sampled rise/run grade. Try the full step, then
 * X-only, then Z-only, preserving downhill travel and sliding along a traversable axis.
 * The sampler can represent a game's terrain policy independently of the ground used for feet.
 * This endpoint test also applies while jumping; it is not continuous terrain collision.
 * @capability uphill-grade-step constrain sampled heightfield ascent with axis sliding and a configurable terrain-policy sampler
 */
export declare function resolveTerrainGradeStep(sampler: {
    sampleHeight(x: number, z: number): number;
} | ((x: number, z: number) => number), position: readonly [number, number, number], stepX: number, stepZ: number, maxClimbGrade: number): {
    stepX: number;
    stepZ: number;
};