Manuel Pagliuca A.Y. 2020/2021 Master’s Degree Computer Science Real Time Graphics Programming Sommario RENDERING PIPELINE .................................................................................................................................................. 6 IMAGE-ORIENTED ................................................................................................................................................................ 6 OBJECT-ORIENTED ............................................................................................................................................................... 6 REAL-TIME RENDERING PIPELINE ................................................................................................................................ 8 APPLICATION STAGE ............................................................................................................................................................ 9 GEOMETRY PROCESSING STAGE ............................................................................................................................................. 9 1. Vertex Shading ..................................................................................................................................................... 10 2. Projection ............................................................................................................................................................. 10 3. Clipping ................................................................................................................................................................ 11 4. Screen Mapping ................................................................................................................................................... 11 RASTERIZATION STAGE ....................................................................................................................................................... 11 FRAGMENT PROCESSING ..................................................................................................................................................... 12 Z-buffer algorithm .................................................................................................................................................... 13 PIPELINE PERFORMANCE ...........................................................................................................................................15 GPU PIPELINES .....................................................................................................................................................17 VERTEX SHADER ................................................................................................................................................................ 18 TESSELLATION SHADER ....................................................................................................................................................... 18 GEOMETRY SHADER ........................................................................................................................................................... 19 FRAGMENT SHADER (OR PIXEL SHADER) ................................................................................................................................ 19 DEFERRED RENDERING ....................................................................................................................................................... 20 SHADER MODEL ...................................................................................................................................................22 UNIFIED SHADER MODEL .................................................................................................................................................... 22 UNIFIED ARCHITECTURE ...................................................................................................................................................... 22 GPGPU .......................................................................................................................................................................... 22 POLYGON MESHES .....................................................................................................................................................23 EULER’S POLYHEDRON FORMULA .......................................................................................................................................... 24 MESH PRODUCTION TECHNIQUES ......................................................................................................................................... 25 High poly vs Low poly ............................................................................................................................................... 25 MAIN 3D FILE FORMATS ..................................................................................................................................................... 26 DATA STRUCTURE FOR POLYGON MESH ................................................................................................................................. 28 Indexed mesh ........................................................................................................................................................... 28 Half-edge .................................................................................................................................................................. 29 MESH ELABORATION .......................................................................................................................................................... 30 Tessellation .............................................................................................................................................................. 31 Consolidation ........................................................................................................................................................... 31 Simplification ........................................................................................................................................................... 32 TERRAIN RENDERING (VIEW-DEPENDANT) .............................................................................................................................. 35 TRANSFORMATIONS AND PROJECTIONS ...................................................................................................................36 SCALE TRANSFORMATION ................................................................................................................................................... 37 ROTATION TRANSFORMATION ............................................................................................................................................. 37 TRANSLATION ................................................................................................................................................................... 38 1 Manuel Pagliuca A.Y. 2020/2021 Master’s Degree Computer Science HOMOGENEUS COORDINATES .............................................................................................................................................. 39 INTERPRETATION OF TRANSFORMATIONS ................................................................................................................................ 43 AFFINE TRANSFORMATIONS IN THE 3D .................................................................................................................................. 43 EULER ANGLES .................................................................................................................................................................. 44 AXIS/ANGLE ROTATION ...................................................................................................................................................... 45 QUATERNIONS .................................................................................................................................................................. 45 PERSPECTIVE .................................................................................................................................................................... 47 CANONICAL CONFIGURATION FOR PARALLEL PROJECTION ........................................................................................................... 49 CANONICAL CONFIGURATION FOR PERSPECTIVE PROJECTION ...................................................................................................... 50 VIEW TRANSFORMATION .................................................................................................................................................... 52 LOOKAT ...................................................................................................................... ERRORE. IL SEGNALIBRO NON È DEFINITO. VIEW-FRUSTUM ................................................................................................................................................................ 54 THE CANONICAL VIEW VOLUME ............................................................................................................................................ 55 WINDOW TO VIEWPORT TRANSFORMATION ........................................................................................................................... 57 SPATIAL DATA STRUCTURES ......................................................................................................................................60