Animation Retargeting

Drive a rigged 3D character with BVH motion data and output an animated GLB. Bone proportion differences are handled automatically. input_motion accepts the asset_path returned directly from the Motion Retrieval API.

Typical Application Scenarios

• Game character animation: Retarget motion-capture BVH onto custom characters
• Chain with Motion Retrieval: search → get asset_path → pass to this API for a fully automated pipeline

Recommended Workflow

1. Prepare a rigged model → GLB with embedded skeleton/skin (input_model)
2. Specify the motion → use the asset_path from Motion Retrieval, or upload a BVH file (input_motion)
3. Set frame rate → use fps: 30 or fps: -1 to keep the source rate
4. Get the animated GLB → result is a GLB with embedded animation tracks, ready for any 3D engine

API Reference used on this page POST /motions/animations

Chaining with Motion Retrieval

Pass the asset_path from Motion Retrieval results (e.g. motions/h3d/bvh/00035389_000.bvh) directly as input_motion — no download needed.

Basic Examples

cURL

curl -X POST 'https://api.v2fun.ai/api/v1/motions/animations' \
  -H 'Authorization: Bearer $V2FUN_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
      "input_model": "models/example_rigged.glb",
      "input_motion": "motions/example.bvh"
    }'

JavaScript

const response = await fetch('https://api.v2fun.ai/api/v1/motions/animations', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer $V2FUN_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "input_model": "models/example_rigged.glb",
    "input_motion": "motions/example.bvh"
  }),
});
const data = await response.json();

Python

import requests

resp = requests.post(
    'https://api.v2fun.ai/api/v1/motions/animations',
    headers={
        'Authorization': 'Bearer $V2FUN_API_KEY',
        'Content-Type': 'application/json',
    },
    json={
        "input_model": "models/example_rigged.glb",
        "input_motion": "motions/example.bvh"
    },
)
print(resp.json())

Java

import java.net.URI;
import java.net.http.*;

HttpClient client = HttpClient.newHttpClient();
String body = "{\"input_model\":\"models/example_rigged.glb\",\"input_motion\":\"motions/example.bvh\"}";
HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://api.v2fun.ai/api/v1/motions/animations"))
    .header("Authorization", "Bearer $V2FUN_API_KEY")
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString(body))
    .build();
HttpResponse<String> response = client.send(
    request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

Core Use Cases

Retarget Motion to Character

Maps BVH motion-capture data onto a rigged character, producing a GLB with complete animation tracks. The input is the static rigged model; the output is the animated version (playable in the viewer).

cURL

curl -X POST 'https://api.v2fun.ai/api/v1/motions/animations' \
  -H 'Authorization: Bearer $V2FUN_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
      "input_model": "https://asset.v2fun.ai/upload/animation-input-mannequin.glb",
      "input_motion": "motions/h3d/bvh/00041332_000.bvh",
      "fps": 30
    }'

JavaScript

const response = await fetch('https://api.v2fun.ai/api/v1/motions/animations', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer $V2FUN_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "input_model": "https://asset.v2fun.ai/upload/animation-input-mannequin.glb",
    "input_motion": "motions/h3d/bvh/00041332_000.bvh",
    "fps": 30
  }),
});
const data = await response.json();

Python

import requests

resp = requests.post(
    'https://api.v2fun.ai/api/v1/motions/animations',
    headers={
        'Authorization': 'Bearer $V2FUN_API_KEY',
        'Content-Type': 'application/json',
    },
    json={
        "input_model": "https://asset.v2fun.ai/upload/animation-input-mannequin.glb",
        "input_motion": "motions/h3d/bvh/00041332_000.bvh",
        "fps": 30
    },
)
print(resp.json())

Java

import java.net.URI;
import java.net.http.*;

HttpClient client = HttpClient.newHttpClient();
String body = "{\"input_model\":\"https://asset.v2fun.ai/upload/animation-input-mannequin.glb\",\"input_motion\":\"motions/h3d/bvh/00041332_000.bvh\",\"fps\":30}";
HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://api.v2fun.ai/api/v1/motions/animations"))
    .header("Authorization", "Bearer $V2FUN_API_KEY")
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString(body))
    .build();
HttpResponse<String> response = client.send(
    request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

Input Model (rigged)

Output

Example response:

{
  "status": "COMPLETED",
  "result": "models/867a17e3-ec0e-4977-8b14-6a44cc69c9cb.glb",
  "metadata": [
    {
      "t_pose_model": "models/be3d686b-4779-4e90-b2e1-ef4fc3f4800a.glb",
      "downloads": [
        {
          "asset_path": "models/867a17e3-ec0e-4977-8b14-6a44cc69c9cb.glb",
          "download_url": "https://..."
        }
      ]
    }
  ]
}

The returned GLB contains embedded animation tracks and can be imported directly into Unity, Unreal, Three.js, and other engines.