Non-Line-of-Sight Transient Rendering

BSTRACTTransient imaging methods often analyze time-resolved light transport for applications such as range imaging, reflectance estimation and, especially, non-line-of-sight (NLOS) imaging, which targets the reconstruction of hidden geometry using measurements of indirect diffuse reflections emitted by a laser. Transient rendering is a key tool for developing such new applications. In this work, we introduce a set of simple, yet effective subpath sampling techniques targeting transient light transport simulation in occluded scenes. We analyze the usual capture setups of NLOS scenes, where the light and camera indirectly aim at hidden geometry through a secondary surface. We leverage that configuration to reduce the integration path space. We implement our techniques in our modified version of Mitsuba 2, adapted for transient light transport, allowing us to support parallelization, polarization, and differentiable rendering.