Plan4D: Generative Plannable 4D Worlds

NeurIPS 2026

1 PVG, Nanyang Technological University2 AMAP, Alibaba Group

† Corresponding authors

One image + text. A generated 4D future. Future RGB, depth, and dynamic geometry from a single observed frame and an action. Tracks are visualized from the generated RGB and predicted geometry. 1080p

Abstract

Most world models for future prediction prioritize the aesthetic quality of generated videos, but offer only limited geometric consistency over time, due to the lack of explicit 4D modeling. In this paper, we introduce Plan4D, a possible next milestone towards building a generative plannable 4D world model that predicts future RGB videos together with dense 4D geometry, including depth, cameras, point clouds, and scene flow, from an observed scene context and text-specified actions. Since training data with paired actions and dense 4D annotations is inherently scarce, Plan4D leverages the complementary priors of foundational video generators and 3D reconstructors. Specifically, we propose a model-stitching architecture that couples Depth Anything 3 with LongCat-Video and augments it with an auxiliary DPT head for scene-flow prediction. The resulting model allows us to plan and generate complex, long-horizon, and fine-grained actions in dynamic 3D scenes, while substantially improving both visual fidelity and geometric accuracy of the generated future videos. Extensive experiments on both synthetic and real-world datasets demonstrate that Plan4D achieves state-of-the-art performance in generative 4D modeling of environmental reactions.

01

Action-conditioned futures

Observed context and a planned action specify how the scene evolves.

02

A shared latent trajectory

RGB, depth, cameras, and scene flow are synchronized readouts of one generated world.

03

Geometry-guided generation

A frozen stitched decoder provides geometric supervision to the video generator.

Action-conditioned world generation

Action-conditioned 4D generation

Everyday interactions, generated from an observed image and a text-specified action.

6 scenes 81 frames
Plan4D (ours)
Input image
01 P02_122_161 Input text

pour eggs, tomatoes and pepper from plate into pan

Interactive 4D output
Gen3R 01 / 81
Plan4D Ours Interactive 4D output
Plan4D 01 / 81
Loading 01 / 81

All 81 time steps are retained. Point clouds are uniformly subsampled to at most 16,000 points per frame for the web. Views are aligned to each sequence's first camera and independently scaled for display.

Interactive 4D output

Plan4D

01 / 81

Aggregated 4D Point Cloud

6 scenes
Plan4D (ours)
Input image
01 Input text

Hold the stabilizer steady. Walk across the grassy area. Maintain the stabilizer's position. Ensure the camera stays balanced.

Aggregated point cloud
Gen3R
Plan4D Ours Aggregated point cloud
Plan4D

Up to 200,000 uniformly sampled scene points per method. All camera-frustum and trajectory points are retained. Each cloud uses its first camera orientation and an independent display scale.

The framework

Two foundation models. One 4D world.

A latent-to-geometry connection joins a video generator with a dynamic 3D reconstruction model.

Plan4D architecture: LongCat-Video generates a latent trajectory, a stitching module maps it into DA3 tokens, and dense heads decode depth, camera rays and scene flow.
Overview of the Plan4D pipeline. A video generator produces a denoised latent trajectory, while a stitched DA3 decoder reads the same latent state to recover synchronized depth, camera rays, camera parameters, point clouds, and scene flow. During joint training, the stitched decoder is frozen and acts as a differentiable geometry critic for the video generator; at inference time, RGB video and dense 4D structure are decoded from the shared latent trajectory.
01 / Motion

Read out scene flow

A DPT-style motion head predicts dense 3D displacements from frozen DA3 features.

02 / Stitching

Connect latent and geometry

A compact spatiotemporal projection maps video latents into the reconstruction backbone.

03 / Calibration

Preserve geometric priors

Teacher distillation and annotated geometry calibrate the stitched decoder.

04 / Joint training

Ground future generation

Flow matching and geometric supervision shape a visually and spatially consistent rollout.

Reference

BibTeX

@inproceedings{zhang2026plan4d,
  title     = {Plan4D: Generative Plannable 4D Worlds},
  author    = {Zhang, Hangwei and Dang, Rujing and Lin, Ruimin and
               Wu, Jiahong and Chu, Xiangxiang and Zheng, Chuanxia},
  booktitle = {Advances in Neural Information Processing Systems (NeurIPS)},
  year      = {2026}
}

Input image

Input text