We present PhySG, an end-to-end inverse rendering pipeline that includes a fully differentiable renderer and can reconstruct geometry, materials, and illumination from scratch from a set of RGB input images. Our framework represents specular BRDFs and environmental illumination using mixtures of spherical Gaussians, and represents geometry as a signed distance function parameterized as a Multi-Layer Perceptron. The use of spherical Gaussians allows us to efficiently solve for approximate light transport, and our method works on scenes with challenging non-Lambertian reflectance captured under natural, static illumination. We demonstrate, with both synthetic and real data, that our reconstructions not only enable rendering of novel viewpoints, but also physics-based appearance editing of materials and illumination.

本研究提出了一种端到端的反演渲染管道，该管道包括可完全不可微的渲染器，可以从一组RGB输入图像重新构建几何，材料和照明，并使用球形高斯混合表示光谱BRDF和环境光，并将几何表示为一个多层感知器参数化的有符号距离函数。使用球形高斯函数使我们能够有效地求解近似光传输问题，并且我们的方法适用于在自然的静态照明下捕获的具有挑战性的非Lambertian反射场景。我们证明了我们的重构不仅使新视点的渲染成为可能，而且还可以对材料和照明进行物理基础的外观编辑。

基于球形高斯函数的物理反渲染用于材料编辑和重新照明