Holistic 4D Reconstruction as
Geometric Control for Video Diffusion

1Visual Geometry Group, University of Oxford 2Nanyang Technological University
* Equal contribution

NeurIPS 2026

One source video. Persistent 3D tracks. New viewpoints.

Abstract

A 4D scaffold to tame video generation.

Synthesizing a monocular video from a new camera trajectory requires preserving the observed scene geometry and motion while completing regions that become newly visible. Feed-forward 4D reconstructors recover the structure of the observed scene, whereas video diffusion models provide a generative prior for completing unseen content. We introduce Holo4D, a video reshooting framework that uses reconstructed 3D trajectories as a holistic source-view 4D scaffold. We project these trajectories into the requested views and encode their geometry and source appearance to guide a pretrained video diffusion model. Together with the source video and target cameras, the scaffold grounds generation in reconstructed observations while leaving unsupported regions to the generative prior. Experiments demonstrate the value of trajectory-based conditioning for camera control and novel-view synthesis. The framework accommodates different 4D reconstructors without retraining the video generator, allowing it to benefit from future advances in source reconstruction.

Holo4D teaser

Each tile: the source video (inset) and the Holo4D result from a new camera path, guided by persistent 3D tracks.

How it works

Persistent tracks, generative completion.

Source reconstruction supplies persistent 3D tracks. Their features are projected into the requested camera and injected into video diffusion, alongside source video and camera-ray features.

Top (4D scaffold): a 4D reconstructor recovers persistent 3D trajectories with sampled source colors, which are projected into the target cameras and encoded into track features T. Bottom (video diffusion): source and noisy target latents are concatenated along width; each DiT block concatenates T with its hidden features along channels and adds camera features C from Plücker rays. Flames and snowflakes mark trained and frozen modules; the top-right track overlay is for visualization only. Full-resolution figure

Takeaway

Reconstruct what was seen; generate what was not.

A 4D scaffold of persistent 3D trajectories grounds video generation in what the source video observed, and leaves only the unseen to the generative prior.

Source geometry keeps the camera on track. On DAVIS, Holo4D has the lowest trajectory and translation errors of all methods; with the same 4RC reconstruction it reduces ATE by 54% and RPE-T by 33% compared with Vista4D. With the two-stage backend it obtains the best PSNR and LPIPS on iPhone.

Generated views keep the scene's geometry. Holo4D has the lowest AbsRel and highest δ1 under both VGGT-Ω and 4RC as output reconstructors; under VGGT-Ω, AbsRel falls from Vista4D's 0.628 to 0.423.

Swap the reconstructor, keep the generator. The same generator accepts 4RC, V-DPM and VGGT-Ω paired with Open-D4RT or CoWTracker, without retraining. The backends trade off (CoWTracker: best ATE, PSNR and SSIM; V-DPM: best rotation error; 4RC: best LPIPS), so Holo4D benefits directly from better reconstructors.

Channel-wise conditioning is lighter. Track features join the hidden features along channels, so the attention sequence length is unchanged: denoising is 1.34× faster than Vista4D at similar peak memory (end-to-end time per video is similar).

It transfers to robots. Trained without robot videos, Holo4D-14B reshoots DROID manipulation episodes and humanoid-robot clips without fine-tuning.

Limits. Holo4D remains sensitive to geometric error, incomplete source coverage and difficult camera trajectories.

Acknowledgements

We thank Runjia Li, Zeqi Xiao, Yiming Chen, Wenqi Ouyang, Zhouxia Wang and Minghao Chen for valuable feedback and discussions. This research was supported by the Sony Research Award Programme 2024, ERC CoG UNION (101001212) and EPSRC EP/Z001811/1 SYN3D. We thank the Isambard-AI and Dawn AIRR supercomputers for supporting this project.

Concurrent works

  • Vista4D conditions on rendered point clouds with persistent static pixels; Holo4D makes moving points persistent too and injects them along channels, without an extra token stream.
  • Lyra [1, 2] distills video diffusion into 3D Gaussians; Holo4D goes the other way, using 4D reconstruction to guide video generation.
  • Atlas is a multimodal world model for views, video and 3D; Holo4D focuses on reshooting one monocular video and swaps reconstructors without retraining.

BibTeX

@inproceedings{lan2026holo4d,
  title  = {{Holo4D}: Holistic 4D Reconstruction as Geometric
            Control for Video Diffusion},
  author = {Lan, Yushi and Jiang, Zeren and Namekata, Koichi and
            Pan, Xingang and Zheng, Chuanxia and Vedaldi, Andrea},
  booktitle = {Advances in Neural Information Processing Systems},
  year   = {2026}
}