Low-Light-Level Simulations and Extended Area Source Modeling Emmett Ientilucci October 11, 2001 Contents 1 Introduction 7 2 Simulation of Point Sources 7 2.1 Isotropic Point Sources ...................... 7 2.2 Non-Isotropic and Directional Point Sources .......... 7 3 Simulation of Extended Sources 10 3.1 Global Illumination ........................ 11 3.1.1 Ray Tracing, Radiosity, and Alternative Solutions .. 11 3.2 Methodology for Ray Tracing Extended Area Sources .... 13 3.2.1 Pre-Render Calculations ................. 13 3.2.2 Pre-Render Calculation of Source Area ......... 13 3.2.3 Rendering ......................... 14 3.3 Extended Area Source Results ................. 19 3.3.1 Ray-Tracing to a Directionally Shaped Point Source . 19 3.3.2 Radiosity Solutions for an Extended Area Source . . . 20 3.3.3 Ray-Tracing to an Extended Area Source ....... 21 3.3.4 Quantitative Veriļ¬cation of Test Room Results .... 26 3.3.5 Extended Area Sources on Vehicle ........... 28 3.3.6 Summary of User-Controllable Variables ........ 29 3.4 Additional Implementation: Foxbat and Hawkeye Scenes . . . 33 4 Addition of Lunar Scattering 39 1