LTC‐IR: Multiview Edge‐Aware Inverse Rendering with Linearly Transformed Cosines

Abstract Decomposing environmental lighting and materials is challenging as they are tightly intertwined and integrated over the hemisphere. In order to precisely decouple them, the lighting representation must represent general image features such as object boundaries or texture contrast, called light edges, which are often neglected in the existing inverse rendering methods. In this paper, we propose an inverse rendering method that efficiently captures light edges. We introduce a triangle mesh‐based light representation that can express light edges by aligning triangle edges with light edges. We exploit the linearly transformed cosines as BRDF approximations to efficiently compute environmental lighting with our light representation. Our edge‐aware inverse rendering precisely decouples distributions of reflectance and lighting through differentiable rendering by jointly reconstructing light edges and estimating the BRDF parameters. Our experiments, including various material/scene settings and ablation studies, demonstrate the reconstruction performance and computational efficiency of our method.