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README.md

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+---
+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.