View synthesis in the scattering medium faces challenges due to image degradation caused by medium scattering, and existing methods struggle to effectively address this issue. Although Neural Radiance Fields (NeRFs) excel in novel view synthesis and high-quality 3D reconstruction, they suffer from slow training speeds and poor handling of scenes with scattering. However, 3D Gaussian Splatting (3DGS) naturally exhibits sparsity, allowing for efficient representation of complex opaque geometries and surface details, but it is limited in modeling medium scattering. To address these limitations, we propose a novel method that combines the volumetric rendering strengths of NeRF with the sparse representation capabilities of 3DGS to effectively handle scattering media. By using 3DGS to represent objects and leveraging volumetric rendering for medium modeling, our method can mitigate the effects of medium scattering, rendering clear scenes in scattering media and synthesizing the appearance and depth of distant objects from novel viewpoints. The experimental results demonstrate a significant improvement in the performance of view-synthesis tasks, with an average increase of 3 to 4 dB. The rendering efficiency improved, with the training time reduced to 8 minutes, while preserving fine details.

Time-of-flight (ToF) devices have greatly propelled the advancement of various multi-modal perception applications. However, achieving accurate rendering of time-resolved information remains a challenge, particularly in scenes involving complex geometries, diverse materials and participating media. Existing ToF rendering works have demonstrated notable results, yet they struggle with scenes involving scattering media and camera-warped settings. Other steady-state volumetric rendering methods exhibit significant bias or variance when directly applied to ToF rendering tasks. To address these challenges, we integrate transient diffusion theory into path construction and propose novel sampling methods for free-path distance and scattering direction, via resampled importance sampling and offline tabulation. An elliptical sampling method is further adapted to provide controllable vertex connection satisfying any required photon traversal time. In contrast to the existing temporal uniform sampling strategy, our method is the first to consider the contribution of transient radiance to importance-sample the full path, and thus enables improved temporal path construction under multiple scattering settings. The proposed method can be integrated into both path tracing and photon-based frameworks, delivering significant improvements in quality and efficiency with at least a 5x MSE reduction versus SOTA methods in equal rendering time.