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PixWorld: Unifying 3D Scene Generation and Reconstruction in Pixel Space

Trains a single diffusion model that unifies 3D scene reconstruction and generative modeling by operating directly in pixel/rendered-image space. Supervises diffusion on rendered views and adds a geometry-perception loss from a pretrained 3D foundation model, reducing latent information loss and improving 3D fidelity.

Introduction

Most prior systems split 3D reconstruction (pixel-wise regression) and 3D generation (latent-space diffusion), causing information loss and misaligned objectives. PixWorld’s core insight is to move diffusion back into pixel/rendered-image space and add geometry-aware supervision, so a single model can both faithfully reconstruct observed views and plausibly generate unseen regions.

Key Findings
  • Pixel-space diffusion aligns the training objective with rendered-image fidelity, avoiding the information bottleneck introduced by VAEs or representation autoencoders used in latent-space pipelines. This means render-level errors directly guide the model toward view-consistent geometry and appearance.
  • Geometry perception loss: rendered views are compared in the feature space of a pretrained 3D foundation model, providing explicit 3D-structural supervision beyond photometric or perceptual 2D losses. This injects geometric awareness without changing the core pixel-space supervision.
  • Unified model behavior: the same pixel-space diffusion model supports both reconstruction (recovering observed surfaces with high fidelity) and generation (plausible completion of unobserved regions), outperforming prior latent-space generators and matching state-of-the-art reconstruction methods in reported evaluations.
Who it's for & Tradeoffs

Great fit if you need a single pipeline that tightly couples photorealistic render fidelity with 3D structural consistency — for tasks like single-view asset creation, multi-view synthesis, or pipelines that must avoid VAE/RAE-induced information loss. Look elsewhere if you require extremely compact latent deployments (PixWorld deliberately avoids latent bottlenecks) or if your workflow depends on pretrained VAE/RAE ecosystems and tooling; pixel-space diffusion can be more memory- and compute-intensive during training and rendering.

Where it fits

PixWorld repositions the design choice in 3D generation research: instead of compressing images into a latent manifold then diffusing, it enforces pixel-level correspondence by supervising rendered outputs and supplementing with geometry-aware feature losses. This makes it a natural complement to reconstruction-focused methods and a practical alternative to latent-space generative systems when fidelity to input views is the priority.

Information

  • Websitearxiv.org
  • AuthorsSensen Gao, Zhaoqing Wang, Qihang Cao, Dongdong Yu, Changhu Wang, Jia-Wang Bian
  • Published date2026/07/06

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