---
license: cc-by-4.0
task_categories:
  - image-to-3d
tags:
  - 4d
  - multiview
  - mesh
  - animation
  - benchmark
size_categories:
  - n<1K
---

# MV4DBench

A 31-item multi-view 4D animated mesh benchmark for evaluating image/video → 4D mesh
reconstruction methods. Each item is rendered from 8 azimuths × N source frames and
ships with a tracked ground-truth point-cloud (T=16, N=100k, xyz+normal) for chamfer
distance evaluation.

## Items

31 animated GLBs sourced from a curated subset of 3D animations (mixamo characters,
animal/object scans, etc.). Frame counts range 11 to 757; renders are at 1024×1024,
24 fps, radius=2.2, elevation=15°.

## Layout

```
<uid>/
├── source.glb              # original animated mesh
├── meta.json               # camera matrices, frame count, fps, etc.
├── rgba_8views/view_NN_azDDD/frame_*.png   # 8 azimuths, transparent bg
├── rgb_8views/view_NN_azDDD/frame_*.png    # 8 azimuths, white bg
├── anim_4views/view_azDDD.mp4               # 4 azimuths, MP4 videos
└── gt_surfaces.npy   # (16, 100000, 6) tracked GT point cloud, normalized to [-1,1]^3
```

The `gt_surfaces.npy` is sampled at 16 evenly-spaced source-frame indices, with
barycentric tracking on the rest-pose mesh, then normalized so the entire animation
fits in a [-1,1]^3 cube (matching the bpyrenderer scene-normalization used during
RGBA rendering — so chamfer scores stay scale-aligned).

## UID mapping

Some original UIDs included whitespace/`|` chars; those are sanitized to the leading
hex stem here. `uid_mapping.json` records the original full names for traceability.

## Citation

Used as held-out evaluation for the multi-view test-time-adaptation extension of
ActionMesh (Meta, 2024). See accompanying paper for chamfer benchmark numbers.