Inverse Rendering using Multi-Bounce Path Tracing and Reservoir Sampling

We introduce MIRReS, a novel two-stage inverse rendering framework thatjointly reconstructs and optimizes explicit geometry, materials, and lightingfrom multi-view images. Unlike previous methods that rely on implicit irradiance fields or oversimplified ray tracing, our method begins with an initialstage that extracts an explicit triangular mesh. In the second stage, we refine this representation using a physically-based inverse rendering modelwith multi-bounce path tracing and Monte Carlo integration. This enables our method to accurately estimate indirect illumination effects, including self-shadowing and internal reflections, leading to a more preciseintrinsic decomposition of shape, material, and lighting. To address thenoise issue in Monte Carlo integration, we incorporate reservoir sampling,improving convergence and enabling efficient gradient-based optimizationwith low sample counts. Through both qualitative and quantitative assessments across various scenarios, especially those with complex shadows,we demonstrate that our method achieves state-of-the-art decompositionperformance. Furthermore, our optimized explicit geometry seamlesslyintegrates with modern graphics engines supporting downstream applications such as scene editing, relighting, and material editing.