We present Bidirectional Gaussian Primitives, an image-based novel view synthesis technique designed to represent and render 3D objects with surface and volumetric materials under dynamic illumination. Our approach integrates light intrinsic decomposition into the Gaussian splatting framework, enabling real-time relighting of 3D objects. To unify surface and volumetric material within a cohesive appearance model, we adopt a light- and view-dependent scattering representation via bidirectional spherical harmonics. Our model does not use a specific surface normal-related reflectance function, making it more compatible with volumetric representations like Gaussian splatting, where the normals are undefined. We demonstrate our method by reconstructing and rendering objects with complex materials. Using One-Light-At-a-Time (OLAT) data as input, we can reproduce photorealistic appearances under novel lighting conditions in real time.
我们提出了双向高斯原语（Bidirectional Gaussian Primitives），这是一种基于图像的新视图合成技术，旨在在动态光照下表示和渲染具有表面和体积材料的 3D 对象。我们的方法将光的内在分解集成到高斯点云框架中，实现了 3D 对象的实时重光照。为了将表面和体积材料统一到一个一致的外观模型中，我们采用了基于双向球面谐波的光照和视角依赖散射表示。我们的模型不使用特定的表面法线相关反射函数，因此更适合与高斯点云等体积表示配合使用，因为这些表示中法线是未定义的。我们通过重建和渲染具有复杂材料的对象来展示我们的方法。利用逐光源（One-Light-At-a-Time, OLAT）数据作为输入，我们能够在新光照条件下实时重现逼真的外观。