We present a method for consistent lighting and shadows when animated 3D Gaussian Splatting (3DGS) avatars interact with 3DGS scenes or with dynamic objects inserted into otherwise static scenes. Our key contribution is Deep Gaussian Shadow Maps (DGSM), a modern analogue of the classical shadow mapping algorithm tailored to the volumetric 3DGS representation. Building on the classic deep shadow mapping idea, we show that 3DGS admits closed form light accumulation along light rays, enabling volumetric shadow computation without meshing. For each estimated light, we tabulate transmittance over concentric radial shells and store them in octahedral atlases, which modern GPUs can sample in real time per query to attenuate affected scene Gaussians and thus cast and receive shadows consistently. To relight moving avatars, we approximate the local environment illumination with HDRI probes represented in a spherical harmonic (SH) basis and apply a fast per Gaussian radiance transfer, avoiding explicit BRDF estimation or offline optimization. We demonstrate environment consistent lighting for avatars from AvatarX and ActorsHQ, composited into ScanNet++, DL3DV, and SuperSplat scenes, and show interactions with inserted objects. Across single and multi avatar settings, DGSM and SH relighting operate fully in the volumetric 3DGS representation, yielding coherent shadows and relighting while avoiding meshing.

翻译：本文提出一种方法，用于在动画化的3D高斯泼溅（3DGS）化身与3DGS场景交互、或与插入静态场景的动态物体交互时，实现一致的光照与阴影效果。我们的核心贡献是深度高斯阴影映射（DGSM），这是一种针对体积化3DGS表示量身定制的经典阴影映射算法的现代类比。基于经典的深度阴影映射思想，我们证明了3DGS允许沿光线进行封闭形式的光照累积，从而无需网格化即可实现体积阴影计算。对于每个估计的光源，我们在同心径向壳层上列表记录透射率，并将其存储在八面体图集中，现代GPU能够针对每次查询实时采样这些数据，以衰减受影响的场景高斯体，从而实现一致的阴影投射与接收。为了对移动化身进行重光照，我们使用以球谐函数（SH）基表示的HDRI探针来近似局部环境光照，并应用快速的高斯体辐射传输，避免了显式的BRDF估计或离线优化。我们展示了来自AvatarX和ActorsHQ的化身在ScanNet++、DL3DV和SuperSplat场景中合成时的环境一致光照效果，以及与插入物体的交互。在单化身和多化身设置中，DGSM与SH重光照完全在体积化3DGS表示中运行，在避免网格化的同时，产生了连贯的阴影和重光照效果。