SceneFrom3D：基于几何条件的户外3D场景生成——通过具有对象级控制的视图调度

摘要

几何条件3D场景生成技术允许用户根据提供的几何结构创建三维环境，从而直接控制场景结构和物体布局。为生成此类3D场景，现有方法通常采用三阶段设计：首先定义视图调度方案，然后沿调度视图合成多视角观测图像，最后从生成的图像中重建三维表示。然而，对于户外场景而言，视图调度成为主要瓶颈——大规模、无结构且无边界的三维几何体使得难以获取既能提供充分覆盖又能支持稳定生成的视图。为解决这一瓶颈，我们提出SceneFrom3D框架，该框架能够从户外输入几何体自动调度视图。SceneFrom3D构建了一个有向生成图，其中节点代表锚定视图，边代表插值轨迹，从而定义了需要合成的视图、需要插值的视图对以及生成过程应遵循的顺序。除自动视图调度外，SceneFrom3D还通过对象级条件控制进一步提升了可控性：为每个对象分配一个身份图像以指导外观生成，并设置几何一致性参数以对输入几何体进行区域级控制。实验表明，SceneFrom3D在几何条件户外3D场景生成任务中达到最优水平，生成的高质量场景兼具可控的对象外观与几何一致性。

English

Geometry-conditioned 3D scene generation enables the creation of 3D environments from user-provided geometry, offering direct control over scene structure and object layout. To generate such 3D scenes, current methods commonly adopt a three-stage design that first defines a view schedule, then synthesizes multi-view observations along the scheduled views, and finally reconstructs a 3D representation from the generated images. However, defining the view schedule becomes a major bottleneck for outdoor scenes, where large, unstructured, and unbounded geometry makes it difficult to obtain views that provide sufficient coverage while supporting stable generation. To address this bottleneck, we present SceneFrom3D, a framework that automatically schedules views from outdoor input geometries. SceneFrom3D constructs a directed generation graph whose nodes represent anchor views and whose edges represent interpolation trajectories, defining which views to synthesize, which view pairs to interpolate, and in which order generation should proceed. Beyond automatic view scheduling, SceneFrom3D further improves controllability through object-level conditioning, assigning each object an identity image for appearance guidance and a geometry-adherence parameter for region-wise control over the input geometry. Experiments demonstrate that SceneFrom3D achieves state-of-the-art geometry-conditioned outdoor 3D scene generation, producing high-quality scenes with controllable object appearance and geometry adherence.