Preprint · under review

TAPESTRY

A single backbone for video
generation and robot control.

Abstract

Pretrained video generation models encode rich priors about physical interactions, but leveraging them for robot control typically requires either resource-intensive video generation at test time or action heads trained from scratch that do not fully utilize the pretrained backbone. We introduce TAPESTRY, a world-action model that repurposes a pretrained video diffusion transformer into a robotic policy without requiring video generation at inference. Our key idea is to treat robot actions as single-patch tokens in the video model's latent space. A lightweight linear projection maps each action timestep to the patch dimensions of the pretrained VAE, and the resulting tokens are processed by the same patchifying layers and transformer backbone used for video.

The shared backbone is optimized through three diffusion objectives sampled per minibatch element: video diffusion on robot and human videos to establish dynamics priors, joint video + action diffusion on robot demonstrations under a coupled timestep and block-causal mask, and action-only diffusion conditioned on clean image latents. At test time, the model generates a compact action token sequence in a single DDIM step from pure noise, producing smooth action chunks at 84 ms per chunk on consumer hardware while avoiding the cost of full video generation.

Method

TAPESTRY architecture: video latents and action patches share patch-embed layers, the pretrained video diffusion backbone, and patch-unembed layers. Three training objectives (video diffusion, joint video+action diffusion, action-only diffusion) are sampled per minibatch element. At inference, the action-only path produces an action chunk in a single 84 ms DDIM step.

TAPESTRY treats robot actions as single-patch tokens in a video generation model's latent space. Video latents and action patches share the same patchifying layers and the same diffusion backbone. The shared backbone is trained jointly on three diffusion objectives, and at test time the policy generates an action chunk in a single DDIM step from pure noise, no video generation required.

In-distribution rollouts

“Open the oven and put the croissant on the plate” · 1× speed
“Put the corn in the bowl” · 1× speed
“Open the lid of the toolbox and put the screwdriver inside” · 1× speed

Out-of-distribution generalization

Novel placement. “Open the oven and put the croissant on the plate” · 1× speed
Novel primitive. “Pour the golf ball out of the bowl” · 1× speed
Novel composition. “Pick up the yellow Lego brick and place it on the wooden boomerang” · 1× speed

Citation

@article{tapestry2026,
  title  = {TAPESTRY: A Single Backbone for Video Generation and Robot Control},
  author = {Anonymous},
  year   = {2026}
}