Accuracy validation

These cases compare LESS simulations with independent theoretical references. Each includes scene settings, equations, results from all three backends and reproduction files.

Case	Quantities and processes tested
A1 - V valley	Lambertian reflection, slope projection, viewing occlusion and energy partition
A2 - Attenuation and single scattering	Transmission and absorption in media and black leaves, plus multi-angle single scattering in a participating medium
A3 - Multiple scattering between parallel planes	Infinite-series energy partition, finite-order contributions and angular BRF
A4 - Thermal radiation cavity	Blackbody radiation, repeated thermal reflections through a transmitting sheet, unequal temperatures and isothermal equilibrium
A5 - LiDAR ranging and waveforms	Analytic intersections and delay, continuous-footprint integrals, slit occlusion, two/three returns, oblique views and beam-sampling convergence
A6 - Scene scale and geometric accuracy	Long rays, large triangles, grazing views and agreement between coarse and refined meshes
A7 - Fluorescence generation and transport	Layer excitation, two-sided fluorescence, infinite multiple reflection/transmission and three-dimensional slit images
A8 - Energy balance, photosynthesis and leaf temperature	Radiation-equilibrium temperature, sensible and latent heat, nonuniform thermal surroundings, dynamic stomata and photosynthesis coupling, energy closure and sampling/iteration convergence
A9 - Microwave brightness and polarization	Bare-soil and absorbing-canopy H/V brightness, finite blocks/gaps, source closure and image convergence