README.md

---
license: cc-by-4.0
tags:
  - novel-view-synthesis
  - scene-extrapolation
  - benchmark
  - dynamic-nvs
  - long-horizon
  - video-diffusion
pretty_name: Scene-Extrapolation Benchmark Suite
---

# Scene-Extrapolation Benchmark Suite

A unified, **honest** evaluation of generative novel-view synthesis (NVS) in the regimes where
per-scene 3D-Gaussian-Splatting reconstruction fails:

- **Extrapolative** — held-out, *unobserved* views (not interpolation between dense captures).
- **Dynamic** — moving foreground content.
- **Long-horizon** — chained / loop-closing camera trajectories where drift accumulates.
- **Memory / revisit** — recall when the camera *returns* to a previously-observed pose (do methods
  remember the scene, or re-hallucinate it?).

One-line framing: **diffusion in the regimes 3DGS fails — extrapolative / dynamic / long-horizon / memory.**

This dataset repo is a **self-contained, offline-playable visualization** of the suite as a live
snapshot. Open `viz_pkg/index.html` by double-click (or browse `index.html` in the repo) — all paths
are relative, videos are embedded H.264, no server needed. A zipped copy is provided as
`scene_extrapolation_benchmark_viz.zip`.

## What's inside

```
viz_pkg/
  index.html                 self-contained page (header + 4 sections, inlined CSS/JS/SVG)
  README.md                  this file
  sections/                  the source HTML fragments + the coverage snapshot JSON
    difficulty.html          the headline Kubric-4D difficulty-curve charts (inline SVG)
    coverage.html / coverage_data.json
    quantitative.html
    qualitative.html
    infer_time.json          per-(method,benchmark) avg inference wall-clock (from SLURM sacct)
  assets/qual/<bench>/<cid>/*.mp4   FULL-RESOLUTION individual per-method clips (H.264 crf 20,
                                    NATIVE resolution — GEN3C 1280×704, ViewCrafter 1024×576,
                                    NVS/SoM 960×540, FrameCrafter/Ours 832×480, Kubric 576×384;
                                    NO downscaling). Laid out in the page as a CSS grid of
                                    lazy-loaded <video> elements (≤4 per row), replacing the old
                                    downscaled composited-grid panels.
  assets/qual/{mv,mb}_*/<cid>/       REVISIT / MEMORY qualitative panels (6 benchmarks:
    *.mp4                            multi_visit + moving_back × dl3dv / spatialvid / kubric4d,
    return/*.png                     ~10 clips each). Per clip: a full-res per-method video grid
                                     surfacing the memory methods (Shape-of-Motion, GEN3C, SpMem,
                                     Voyager, Lyra-2, MatrixGame-3) + Ours + honest revisit-GT,
                                     PLUS a return-frame comparison (return/<method>_pose*.png =
                                     the model's generated frame at the return pose, next to
                                     obsgt_pose*.png = the ORIGINAL observed GT there) with the
                                     reused return/self PSNR·SSIM·LPIPS numbers.
```

**Synchronized playback.** Every qualitative panel (static, dynamic, long-horizon *and* the
revisit panels) has a per-panel **sync controller**: one *Play all* toggle + a shared scrubber
that starts / pauses / **seeks all tiles in lockstep** and loops them together, so the methods are
always compared at the same timestamp while each tile keeps its own native resolution + download.

The page has **four parts**:

1. **Kubric-4D difficulty curve (headline)** — the primary, confound-free dynamic story. Inline-SVG
   line charts of metric-vs-camera-angle-bin (x = 30/60/90/120/180°, one line per method) for
   full-frame PSNR, dynamic-masked mPSNR, LPIPS, and a camera-trajectory error (COLMAP ATE). Every
   method **degrades as the viewpoint widens**; the gap at the hard 120–180° back-views is the real
   test. Ours (`vace14b`) is the bold green line. Charts are pure inline SVG — no CDN, fully offline.
2. **Coverage matrix** — *what we ran*. Rows = all methods (grouped: Ours · diffusion baselines ·
   per-scene 3D-GS · long-horizon world models), columns = the 6 benchmarks across the 3 axes.
   Each cell is `✓ scored (n=N)` / `🔄 running` / `⏭ N/A (reason)` / `— pending`.
3. **Quantitative** — per-benchmark metric tables read directly from
   `runs/<bench>_metrics/<method>.json`. Static: PSNR/SSIM/LPIPS (hole/extrap + full-frame), FID,
   TSED, MEt3R, COLMAP. Dynamic: **Kubric-4D clean-GT** (primary, angle-binned 30/60/90/120/180°, 4
   metric families) + **NVIDIA** dynamic-region-masked mPSNR/mSSIM/mLPIPS (secondary) + SpatialVID.
   Long-horizon: drift (ATE / rotation / loop-closure) + the WorldScore aggregate — now with the
   **LH-SOTA** rows (`lyra2`, `matrixgame3`) scored, the `vace14b_ft_lh` `ft@4000` row filled, and a
   **§4c base-vs-finetune** head-to-head. A dedicated **Memory / revisit** section adds the `mv_*`
   (revisit-consistency) and `mb_*` (return-fidelity) tables across Kubric-4D / DL3DV / SpatialVID.
   Best per column is **bold**; the Ours (`vace14b`) row is highlighted. Each per-benchmark table now also carries an
   **`infer s/clip`** column (last column) and there is a dedicated **§5 Average inference time**
   summary (per-method s/clip with s/frame, sorted fastest→slowest). These are **honest wall-clock**
   numbers from **SLURM `sacct` `ElapsedRaw`** summed over the COMPLETED generation array tasks /
   clips produced (NOT mtime deltas, which parallel array writes make meaningless). Caveats rendered
   inline: it is wall-clock **incl. one-time model-load amortization**; clip lengths differ per
   benchmark so **s/frame** is the cross-benchmark-fair number; per-scene `shape_of_motion` includes
   the **full 4D-GS optimization** (flagged `per-scene`); methods with no `sacct` record show `—`
   (never fabricated). The spread runs from fast feed-forward (Lyra-2 / Matrix-Game ~1.5–2 s/frame)
   through autoregressive-memory (Voyager 13–100 s/frame) to per-scene Shape-of-Motion (~62 s/frame).
4. **Qualitative** — per representative clip, a **CSS grid of individual full-resolution videos**
   (≤4 per row): *observed input | warp / point-cloud | key baselines (incl. FrameCrafter) | Ours |
   GT*, including long-horizon closed-loop / revisit clips. Each `<video>` plays its method's output
   at **native resolution** (no downscaling; `object-fit: contain` normalizes the grid box) and is
   **lazy-loaded** (`preload="none"` + IntersectionObserver load-on-scroll) inside per-benchmark
   collapsible sections, so the page stays responsive despite hundreds of clips. Clip sets: eval50 (12),
   NVIDIA (12), SpatialVID (12), Kubric-4D (25, grouped by 30/60/90/120/180° bin), LH-DL3DV (12,
   grouped by trajectory family). Honest GT handling preserved: synthetic-orbit GT dropped, closed-loop
   GT relabeled "observed-only", unscored methods tagged *(metrics pending)*.

## Benchmarks (12 across 4 axes)

| Axis | Benchmark | Protocol notes |
|---|---|---|
| Static | **DL3DV** (50 held-out clips) | extrapolation into the unobserved region |
| Dynamic | **Kubric-4D** | **PRIMARY** confound-free anchor — standard GCD/AnyView angle-binned protocol, **perfect GT** poses/depth/segmentation (no depth/scale/warp confound). The headline difficulty curve (30/60/90/120/180°) lives at the top of the page |
| Dynamic | **NVIDIA Dynamic Scenes** | **SECONDARY** real-dynamic check — 12-cam static rig (high multi-view factor, "teleporting camera"), dynamic-region-masked mPSNR/mSSIM/mLPIPS |
| Dynamic | **SpatialVID** (30 clips) | in-the-wild dynamic |
| Long-horizon | **LH-DL3DV** (42 clips) | GVS-style drift / loop-closure (orbit · long-straight · closed-loop) |
| Long-horizon | **WorldScore** | Stanford world-generation aggregate (cam-ctrl / 3D-consist / photo / …) |
| Memory / revisit | **multi_visit** (`mv_*`) × {Kubric-4D · DL3DV · SpatialVID} | **REVISIT-CONSISTENCY** — revisit a fixed observed pose; score GT-fidelity (`revisit_psnr/ssim/lpips_gt`) + cross-visit self-consistency drift (`revisit_self_*`, GT-free) |
| Memory / revisit | **moving_back** (`mb_*`) × {Kubric-4D · DL3DV · SpatialVID} | **RETURN-FIDELITY** — move away into unseen space then return; score return-vs-GT + `degrade_vs_observed_psnr` (the forgetting signal) + `away_dist`. Kubric carries a per-away-distance-bin breakdown |

> **Memory axis (NEW):** both families score **only on real GT** (revisit/return legs carry true GT;
> synthetic away-legs are masked upstream). **Headline — explicit geometric caching, not learned memory,
> enables return-fidelity — now confirmed across all three scene types**: static-real DL3DV, synthetic
> Kubric-4D, AND dynamic-real SpatialVID (9 methods scored per family, 52 cells; `spmem` and the
> warp-conditioned `framecrafter` now folded in on **all six** memory benchmarks). Per-scene 4D-GS (`shape_of_motion`) stores the scene and degrades only
> **−0.8 dB** (DL3DV) / **−1.0 dB** (SpatialVID); the best *forward generator* is `gen3c` with an explicit
> 3D point cache, the only generator that stays low on every scene type (**−17.0 dB** DL3DV / **−13.8 dB**
> Kubric / **−17.5 dB** SpatialVID). The dedicated **learned** spatial-memory model `spmem` collapses
> **−30.0 / −24.1 / −32.0 dB** (DL3DV / Kubric / SpatialVID) — among the worst on all three, *uniform across
> static, synthetic and dynamic*, so it is **not a domain gap**. The memoryless single-shot generators
> (`lyra2` / VACE / `viewcrafter` / `nvs_solver`) all collapse **≈ −20 to −32 dB**, and `spmem` sits inside
> that band. (Matrix-Game 3.0's tiny degrade is an artifact of uniformly-low quality, return-PSNR ≈ 11 —
> not memory.) Today's strongest extrapolators have **no working learned memory**; explicit geometry carries it.

> DyCheck (iPhone handheld) was **dropped**: its **portrait** aspect ratio doesn't fit the landscape
> pipeline, so it would be an unfair comparison. The confound-free **Kubric-4D clean-GT** anchor (with
> perfect ground-truth, no warp confound) is the primary dynamic story; NVIDIA is the secondary check.

## Methods

- **Ours (warp+inpaint VACE):** `vace14b` (Wan2.1-VACE-14B, depth-warp control → inpaint) and its
  finetunes `vace14b_ft_lh` / `vace14b_ft_dyn` / `vace14b_ft_mixed`, plus `i2v_base` / `i2v_ft`.
- **Diffusion baselines:** `gen3c`, `voyager`, `flexworld`, `viewcrafter`, `framecrafter`,
  `nvs_solver`, `viewextrapolator`, `trajcrafter`.
- **Per-scene 3D-GS:** `shape_of_motion` (monocular 4D Gaussian fit).
- **Long-horizon world models:** `lyra2`, `matrix3d`, `spmem`, `vmem`, `matrixgame3`.

## Honesty / snapshot caveats

This is a **live snapshot** (2026-06-29) — several jobs are still running. Cells with no scored
`<method>.json` render as `running` / `pending` / `N/A`, **never as a fabricated number**. Notable
state at snapshot time: the long-horizon SOTA rows `lyra2` and `matrixgame3` are now **scored** on the
LH drift probe, and `vace14b_ft_lh` is **scored at `ft@4000`** (see the §4c base-vs-finetune head-to-head);
`spmem` still has no LH metrics json (long-horizon roll still generating, left `running`). The NEW
**Memory / revisit** axis now carries **9 methods scored per benchmark** (52 cells total) across all six families, with
`spmem` and `framecrafter` both folded in on all three scene types; `vmem`/FlexWorld/TrajCrafter/ViewExtrapolator/Voyager
and `spmem` on the still-generating long-horizon set are still rolling out there. The `vace14b` recon metrics on NVIDIA / Kubric summary are still shown as `running` (warp
pipeline still scoring) rather than as numbers.

## Reproduction

Metrics are aggregated from per-clip rows by `code/build_bench.py` into `viz/bench_data.json`; the
Kubric-4D per-angle-bin difficulty curve (inline SVG) is built by `code/build_kubric_curve.py` from
the `by_bin` aggregates; the section fragments and the video panels are built on top, then assembled
into `index.html`. The **inference-time** column/summary is computed by `code/compute_infer_time.py`
(SLURM `sacct` → `sections/infer_time.json`) and injected into the quantitative tables by
`code/add_infer_column.py` (additive, re-runnable, idempotent).