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Zexiang Xu

41 accepted papers

2025

4D-LRM: Large Space-Time Reconstruction Model From and To Any View at Any Time

NeurIPS 2025poster

Can we scale 4D pretraining to learn general space-time representations that reconstruct an object from a few views at some times to any view at any time? We provide an affirmative answer with 4D-LRM, the first large-scale 4D reconstruction model that takes input from unconstrained views and timesta…

Cited by 0SourceScholar
2025

Buffer Anytime: Zero-Shot Video Depth and Normal from Image Priors

CVPR 2025poster

We present Buffer Anytime, a framework for estimation of depth and normal maps (which we call geometric buffers) from video that eliminates the need for paired video--depth and video--normal training data. Instead of relying on large-scale annotated video datasets, we demonstrate high-quality video…

Cited by 2SourcePDFScholar
2025

DMesh++: An Efficient Differentiable Mesh for Complex Shapes

ICCV 2025poster

Recent probabilistic methods for 3D triangular meshes capture diverse shapes by differentiable mesh connectivity, but face high computational costs with increased shape details. We introduce a new differentiable mesh processing method that addresses this challenge and efficiently handles meshes with…

2025

Gaussian Mixture Flow Matching Models

ICML 2025poster

Diffusion models approximate the denoising distribution as a Gaussian and predict its mean, whereas flow matching models reparameterize the Gaussian mean as flow velocity. However, they underperform in few-step sampling due to discretization error and tend to produce over-saturated colors under clas…

2025

Generating 3D-Consistent Videos from Unposed Internet Photos

CVPR 2025poster

We address the problem of generating videos from unposed internet photos. A handful of input images serve as keyframes, and our model interpolates between them to simulate a path moving between the cameras. Given random images, a model's ability to capture underlying geometry, recognize scene identi…

Cited by 1SourcePDFScholar
2025

LVSM: A Large View Synthesis Model with Minimal 3D Inductive Bias

ICLR 2025oral

We propose the Large View Synthesis Model (LVSM), a novel transformer-based approach for scalable and generalizable novel view synthesis from sparse-view inputs. We introduce two architectures: (1) an encoder-decoder LVSM, which encodes input image tokens into a fixed number of 1D latent tokens, fun…

2025

Long-LRM: Long-sequence Large Reconstruction Model for Wide-coverage Gaussian Splats

ICCV 2025poster

We propose Long-LRM, a feed-forward 3D Gaussian reconstruction model for instant, high-resolution, 360deg wide-coverage, scene-level reconstruction. Specifically, it takes in 32 input images at a resolution of 960x540 and produces the Gaussian reconstruction in just 1 second on a single A100 GPU. To…

2025

MegaSynth: Scaling Up 3D Scene Reconstruction with Synthesized Data

CVPR 2025poster

We propose scaling up 3D scene reconstruction by training with synthesized data. At the core of our work is MegaSynth, a procedurally generated 3D dataset comprising 700K scenes - over 50 times larger than the prior real dataset DL3DV - dramatically scaling the training data. To enable scalable data…

Cited by 1SourcePDFScholar
2025

RelitLRM: Generative Relightable Radiance for Large Reconstruction Models

ICLR 2025spotlight

We propose RelitLRM, a Large Reconstruction Model (LRM) for generating high-quality Gaussian splatting representations of 3D objects under novel illuminations from sparse (4-8) posed images captured under unknown static lighting. Unlike prior inverse rendering methods requiring dense captures and sl…

2024

DMV3D: Denoising Multi-view Diffusion Using 3D Large Reconstruction Model

ICLR 2024spotlight

We propose DMV3D, a novel 3D generation approach that uses a transformer-based 3D large reconstruction model to denoise multi-view diffusion. Our reconstruction model incorporates a triplane NeRF representation and, functioning as a denoiser, can denoise noisy multi-view images via 3D NeRF reconstru…

2024

DMesh: A Differentiable Mesh Representation

NeurIPS 2024poster

We present a differentiable representation, DMesh, for general 3D triangular meshes. DMesh considers both the geometry and connectivity information of a mesh. In our design, we first get a set of convex tetrahedra that compactly tessellates the domain based on Weighted Delaunay Triangulation (WDT),…

2024

GS-LRM: Large Reconstruction Model for 3D Gaussian Splatting

ECCV 2024poster

"We propose , a scalable large reconstruction model that can predict high-quality 3D Gaussian primitives from 2-4 posed sparse images in ∼0.23 seconds on single A100 GPU. Our model features a very simple transformer-based architecture; we patchify input posed images, pass the concatenated multi-view…

2024

Instant3D: Fast Text-to-3D with Sparse-view Generation and Large Reconstruction Model

ICLR 2024poster

Text-to-3D with diffusion models has achieved remarkable progress in recent years. However, existing methods either rely on score distillation-based optimization which suffer from slow inference, low diversity and Janus problems, or are feed-forward methods that generate low-quality results due to…

Cited by 250SourcePDFScholar
2024

LRM-Zero: Training Large Reconstruction Models with Synthesized Data

NeurIPS 2024poster

We present LRM-Zero, a Large Reconstruction Model (LRM) trained entirely on synthesized 3D data, achieving high-quality sparse-view 3D reconstruction. The core of LRM-Zero is our procedural 3D dataset, Zeroverse, which is automatically synthesized from simple primitive shapes with random texturing a…

2024

MovingParts: Motion-based 3D Part Discovery in Dynamic Radiance Field

ICLR 2024spotlight

We present MovingParts, a NeRF-based method for dynamic scene reconstruction and part discovery. We consider motion as an important cue for identifying parts, that all particles on the same part share the common motion pattern. From the perspective of fluid simulation, existing deformation-based met…

Cited by 10SourcePDFScholar
2024

Neural Directional Encoding for Efficient and Accurate View-Dependent Appearance Modeling

CVPR 2024highlight

Novel-view synthesis of specular objects like shiny metals or glossy paints remains a significant challenge. Not only the glossy appearance but also global illumination effects including reflections of other objects in the environment are critical components to faithfully reproduce a scene. In this…

2024

Neural Gaffer: Relighting Any Object via Diffusion

NeurIPS 2024poster

Single-image relighting is a challenging task that involves reasoning about the complex interplay between geometry, materials, and lighting. Many prior methods either support only specific categories of images, such as portraits, or require special capture conditions, like using a flashlight. Altern…

Cited by 14SourcePDFScholar
2024

PF-LRM: Pose-Free Large Reconstruction Model for Joint Pose and Shape Prediction

ICLR 2024spotlight

We propose a Pose-Free Large Reconstruction Model (PF-LRM) for reconstructing a 3D object from a few unposed images even with little visual overlap, while simultaneously estimating the relative camera poses in ~1.3 seconds on a single A100 GPU. PF-LRM is a highly scalable method utilizing self-atten…

2024

SuperGaussian: Repurposing Video Models for 3D Super Resolution

ECCV 2024poster

"We present a simple, modular, and generic method that upsamples coarse 3D models by adding geometric and appearance details. While generative 3D models now exist, they do not yet match the quality of their counterparts in image and video domains. We demonstrate that it is possible to directly repur…

2023

One-2-3-45: Any Single Image to 3D Mesh in 45 Seconds without Per-Shape Optimization

NeurIPS 2023poster

Single image 3D reconstruction is an important but challenging task that requires extensive knowledge of our natural world. Many existing methods solve this problem by optimizing a neural radiance field under the guidance of 2D diffusion models but suffer from lengthy optimization time, 3D inconsist…

2023

OpenIllumination: A Multi-Illumination Dataset for Inverse Rendering Evaluation on Real Objects

NeurIPS 2023poster

We introduce OpenIllumination, a real-world dataset containing over 108K images of 64 objects with diverse materials, captured under 72 camera views and a large number of different illuminations. For each image in the dataset, we provide accurate camera parameters, illumination ground truth, and for…

2023

RenderDiffusion: Image Diffusion for 3D Reconstruction, Inpainting and Generation

CVPR 2023poster

Diffusion models currently achieve state-of-the-art performance for both conditional and unconditional image generation. However, so far, image diffusion models do not support tasks required for 3D understanding, such as view-consistent 3D generation or single-view object reconstruction. In this pap…

2023

TensoIR: Tensorial Inverse Rendering

CVPR 2023poster

We propose TensoIR, a novel inverse rendering approach based on tensor factorization and neural fields. Unlike previous works that use purely MLP-based neural fields, thus suffering from low capacity and high computation costs, we extend TensoRF, a state-of-the-art approach for radiance field modeli…

2022

NeRFusion: Fusing Radiance Fields for Large-Scale Scene Reconstruction

CVPR 2022oral

While NeRF has shown great success for neural reconstruction and rendering, its limited MLP capacity and long per-scene optimization times make it challenging to model large-scale indoor scenes. In contrast, classical 3D reconstruction methods can handle large-scale scenes but do not produce realist…

Cited by 125PDFcodeScholar
2022

PhotoScene: Photorealistic Material and Lighting Transfer for Indoor Scenes

CVPR 2022poster

Most indoor 3D scene reconstruction methods focus on recovering 3D geometry and scene layout. In this work, we go beyond this to propose PhotoScene, a framework that takes input image(s) of a scene along with approximately aligned CAD geometry (either reconstructed automatically or manually specifie…

Cited by 31PDFcodeScholar
2022

Physically-Based Editing of Indoor Scene Lighting from a Single Image

ECCV 2022poster

"We present a method to edit complex indoor lighting from a single image with its predicted depth and light source segmentation masks. This is an extremely challenging problem that requires modeling complex light transport, and disentangling HDR lighting from material and geometry with only a partia…

Cited by 61SourcePDFScholar
2022

Point-NeRF: Point-Based Neural Radiance Fields

CVPR 2022oral

Volumetric neural rendering methods like NeRF generate high-quality view synthesis results but are optimized per-scene leading to prohibitive reconstruction time. On the other hand, deep multi-view stereo methods can quickly reconstruct scene geometry via direct network inference. Point-NeRF combine…

Cited by 701PDFcodeScholar
2021

MVSNeRF: Fast Generalizable Radiance Field Reconstruction From Multi-View Stereo

ICCV 2021poster

We present MVSNeRF, a novel neural rendering approach that can efficiently reconstruct neural radiance fields for view synthesis. Unlike prior works on neural radiance fields that consider per-scene optimization on densely captured images, we propose a generic deep neural network that can reconstruc…

Cited by 907PDFcodeScholar
2021

NeuTex: Neural Texture Mapping for Volumetric Neural Rendering

CVPR 2021poster

Recent work has demonstrated that volumetric scene representations combined with differentiable volume rendering can enable photo-realistic rendering for challenging scenes that mesh reconstruction fails on. However, these methods entangle geometry and appearance in a ""black-box"" volume that canno…

Cited by 116PDFScholar
2021

OpenRooms: An Open Framework for Photorealistic Indoor Scene Datasets

CVPR 2021poster

We propose a novel framework for creating large-scale photorealistic datasets of indoor scenes, with ground truth geometry, material, lighting and semantics. Our goal is to make the dataset creation process widely accessible, allowing researchers to transform scans into datasets with highquality gro…

Cited by 93PDFScholar
2020

Deep 3D Capture: Geometry and Reflectance From Sparse Multi-View Images

CVPR 2020poster

We introduce a novel learning-based method to reconstruct the high-quality geometry and complex, spatially-varying BRDF of an arbitrary object from a sparse set of only six images captured by wide-baseline cameras under collocated point lighting. We first estimate per-view depth maps using a deep mu…

Cited by 97PDFScholar
2020

Deep Reflectance Volumes: Relightable Reconstructions from Multi-View Photometric Images

ECCV 2020poster

We present a deep learning approach to reconstruct scene appearance from unstructured images captured under collocated point lighting. At the heart of Deep Reflectance Volumes is a novel volumetric scene representation consisting of opacity, surface normal and reflectance voxel grids. We present a n…

Cited by 133SourcePDFScholar
2020

Deep Stereo Using Adaptive Thin Volume Representation With Uncertainty Awareness

CVPR 2020oral

We present Uncertainty-aware Cascaded Stereo Network (UCS-Net) for 3D reconstruction from multiple RGB images. Multi-view stereo (MVS) aims to reconstruct fine-grained scene geometry from multi-view images. Previous learning-based MVS methods estimate per-view depth using plane sweep volumes (PSVs)…

Cited by 383PDFScholar
2017

Robust Energy Minimization for BRDF-Invariant Shape From Light Fields

CVPR 2017poster

Highly effective optimization frameworks have been developed for traditional multiview stereo relying on lambertian photoconsistency. However, they do not account for complex material properties. On the other hand, recent works have explored PDE invariants for shape recovery with complex BRDFs, but…

Cited by 17PDFScholar