借助三维基础先验实现真实且一致的环绕视角视频生成
Towards Realistic and Consistent Orbital Video Generation via 3D Foundation Priors
把 3D 基础生成模型的潜变量特征(全局潜向量 + 体特征投影的潜图像)通过多尺度 3D 适配器以跨注意力注入视频扩散模型,为长程视角外推(如背面合成)提供完整形状约束,避免显式网格提取;这套「3D 先验条件化视频生成」的接口设计可直接迁移到新视角合成与环绕视角视频生成任务。
原文依据 we introduce a multi-scale 3D adapter to inject feature tokens to the base video model via cross-attention
摘要译文
由模型翻译 · 术语统一 · 请对照原文核对关键结论本文提出一种新方法,可从物体的单张图像生成几何上真实且一致的环绕视角视频。现有视频生成工作大多依赖逐像素注意力来约束帧间视角一致性,但该机制对长程外推(例如背面视角合成)施加的约束不足——在这类情形下,与输入图像存在像素对应的区域十分有限,因此这些方法往往无法生成结构合理且连贯的结果。为解决该问题,我们提出利用三维基础生成模型所蕴含的丰富形状先验作为辅助约束,其动机在于该模型能够对从大规模三维资产语料库中学到的真实物体形状分布进行建模。具体而言,我们用三维基础模型编码的两种尺度的潜变量特征来提示视频生成:(i) 去噪后的全局潜向量,作为整体结构引导;(ii) 一组由体特征投影得到的潜图像,用于提供与视角相关且细粒度的几何细节。与常用的深度图、法线图等 2.5D 表示不同,这些紧凑特征能够建模完整的物体形状,并因无需显式提取网格而有助于提升推理效率。为实现有效的形状条件化,我们引入多尺度三维适配器,通过跨注意力将特征 token 注入基础视频模型,从而保留其来自通用视频预训练的能力,并支持简单且与模型无关的微调流程。在多个基准上的大量实验表明,与最优方法相比,本方法在视觉质量、形状真实感和多视角一致性上均更优,并能稳健地泛化到复杂相机轨迹与真实场景图像。
英文原文摘要 1826 字符
We present a novel method for generating geometrically realistic and consistent orbital videos from a single image of an object. Existing video generation works mostly rely on pixel-wise attention to enforce view consistency across frames. However, such mechanism does not impose sufficient constraints for long-range extrapolation, e.g. rear-view synthesis, in which pixel correspondences to the input image are limited. Consequently, these works often fail to produce results with a plausible and coherent structure. To tackle this issue, we propose to leverage rich shape priors from a 3D foundational generative model as an auxiliary constraint, motivated by its capability of modeling realistic object shape distributions learned from large 3D asset corpora. Specifically, we prompt the video generation with two scales of latent features encoded by the 3D foundation model: (i) a denoised global latent vector as an overall structural guidance, and (ii) a set of latent images projected from volumetric features to provide view-dependent and fine-grained geometry details. In contrast to commonly used 2.5D representations such as depth or normal maps, these compact features can model complete object shapes, and help to improve inference efficiency by avoiding explicit mesh extraction. To achieve effective shape conditioning, we introduce a multi-scale 3D adapter to inject feature tokens to the base video model via cross-attention, which retains its capabilities from general video pretraining and enables a simple and model-agonistic fine-tuning process. Extensive experiments on multiple benchmarks show that our method achieves superior visual quality, shape realism and multi-view consistency compared to state-of-the-art methods, and robustly generalizes to complex camera trajectories and in-the-wild images.