TY  - JOUR
TI  - Physical Light-Matter Interaction in Hermite-Gauss Space
AU  - Shlomi Steinberg
AU  - Ling-Qi Yan
PY  - 2021
T2  - ACM Transactions on Graphics
UR  - https://ssteinberg.xyz/2021/07/31/physical_light_matter_interaction_HG_space/
DO  - 10.1145/3478513.3480530
VL  - 40
IS  - 6
C7  - 283
AB  - Our purpose in this paper is two-fold: introduce a computationally-tractable decomposition of the coherence properties of light; and, present a general-purpose light-matter interaction framework for partially-coherent light. In a recent publication, Steinberg and Yan 2021 introduced a framework that generalises the classical radiometry-based light transport to physical optics. This facilitates a qualitative increase in the scope of optical phenomena that can be rendered, however with the additional expressibility comes greater analytic difficulty: This coherence of light, which is the core quantity of physical light transport, depends initially on the characteristics of the light source, and mutates on interaction with matter and propagation. Furthermore, current tools that aim to quantify the interaction of partially-coherent light with matter remain limited to specific materials and are computationally intensive. To practically represent a wide class of coherence functions, we decompose their modal content in Hermite-Gauss space and derive a set of light-matter interaction formulae, which quantify how matter scatters light and affects its coherence properties. Then, we model matter as a locally-stationary random process, generalizing the prevalent deterministic and stationary stochastic descriptions. This gives rise to a framework that is able to formulate the interaction of arbitrary partially-coherent light with a wide class of matter. Indeed, we will show that our presented formalism unifies a few of the state-of-the-art scatter and diffraction formulae into one cohesive theory. This formulae include the sourcing of partially-coherent light, scatter by rough surfaces and microgeometry, diffraction grating and interference by a layered structure.
KW  - wave
KW  - optics
KW  - coherent
KW  - partially-coherent
KW  - light transport
KW  - path tracing
KW  - optical coherence
KW  - radiometry
KW  - electromagnetism
KW  - interference
KW  - diffraction
KW  - scattering
KW  - rendering equation
KW  - spectral
KW  - polarization
KW  - generalized stokes parameters
KW  - plt
ER  -