2. 2D T EXTURES & T EXTURE M APPING AND S PECIAL E FFECTS T ILING T ILING B UMP M APPING B UMP M APPING E NVIRONMENT AND S HADOW M APPING E NVIRONMENT AND S HADOW M APPING T URBULENCE AND W AVES T URBULENCE AND W AVES S UBDIVISION S URFACES S UBDIVISION S URFACES L EVEL OF D ETAIL L EVEL OF D ETAIL CS 382.001 A PRIL 5, 2016 P ARTS 6.4-6.5

3. 2D T EXTURES AND T EXTURE M APPING P AGE 214 T EXTURES M ODELING ALL OF THE DETAILS OF ELABORATE 3D OBJECTS WOULD BE PROHIBITIVELY EXPENSIVE IN A REAL - RIME GRAPHICS ENVIRONMENT. 2-D I MAGES 3-D G RID T EXTURED M ODELS O NE COMMON, RELATIVELY INEXPENSIVE SOLUTION IS TO MAP A 2D IMAGE, A TEXTURE, ONTO A 3D GRID SURFACE.

4. 2D T EXTURES AND T EXTURE M APPING P AGE 215 T ILING R ATHER THAN CREATE A SINGLE ELABORATE TEXTURE MAP FOR A LARGE OBJECT ( E. G., A TERRAIN ), SEVERAL SMALL TEXTURE MAPS CAN BE USED TO TILE ACROSS THE OBJECT ’ S SURFACE. N OTE HOW EACH TRIANGULAR TEXTURE SAMPLE HAS BOUNDARY CONDITIONS THAT DETERMINE WHICH SAMPLES CAN BE PLACED ADJACENT TO IT SEAMLESSLY.

5. 2D T EXTURES AND T EXTURE M APPING P AGE 216 B UMP M APPING B Y PERFORMING ANGULAR PERTURBATIONS TO THE SURFACE OF AN OBJECT, THE APPEARANCE OF LOCAL GEOMETRIC VARIATIONS CAN BE PRODUCED, YIELDING DIMPLES AND WRINKLES WITHOUT ACTUALLY PERFORMING GEOMETRIC CALCULATIONS DURING THE RENDERING PROCESS. A BUMP - MAPPED OBJECT ( ABOVE ) WITH THE BUMP MAP ( BELOW ) A BUMP - MAPPED OBJECT FROM A PROCEDURALLY GENERATED HEIGHT FIELD C OMBINING BUMP MAPPING WITH COLOR MAPPING W ARNING : T HE SMOOTH SILHOUETTE IS A DEAD GIVEAWAY THAT BUMP MAPPING WAS USED !

6. 2D T EXTURES AND T EXTURE M APPING P AGE 217 E NVIRONMENT M APS & S HADOW M APS R ATHER THAN COMPUTING FULL REFLECTIONS OFF AN ELABORATE OBJECT, SIMPLER REFLECTIONS CAN BE COMPUTED FOR A BOUNDING BOX, THEN PROJECTED ONTO THE OBJECT. S IMILARLY, RATHER THAN COMPUTE ACCURATE SHADOWS, A BOUNDING BOX AROUND THE LIGHT SOURCE CAN BE USED TO ROUGHLY DETERMINE HOW CLOSE A SCENE ’ S OBJECTS ARE TO THE LIGHT AND THE RESULTING SHADOWS ARE “ MAPPED ” TO THE REST OF THE SCENE. T EAPOT E NVIRONMENT M AP L IGHT B ULB S HADOW M AP T RADITIONAL S CENE S CENE WITH E NVIRONMENT & S HADOW M APS

7. 2D T EXTURES AND T EXTURE M APPING P AGE 218 A GGLOMERATION T O REDUCE MEMORY RETRIEVALS WHEN SEVERAL TEXTURES ARE REQUIRED FOR A SINGLE RENDERED OBJECT, THE VARIOUS TEXTURE MAPS CAN BE AGGLOMERATED INTO A SINGLE BITMAP.

8. 2D T EXTURES AND T EXTURE M APPING P AGE 219 T URBULENCE T EXTURES CAN ALSO BE APPLIED TO PRODUCE ILL - DEFINED IMAGES LIKE FLAMES. S MALL IMAGES OF TURBULENT DETAIL ARE MAPPED ONTO DISPLAY PRIMITIVES THAT ARE PROVIDED WITH A PARTICLE SYSTEM BEHAVIOR A LTERNATIVELY, A NOISE FUNCTION CAN BE APPLIED TO A STATIC IMAGE TO PRODUCE TURBULENCE. T HIS FUNCTION IS DESIGNED TO MAINTAIN STATISTICAL INVARIANCE UNDER TRANSLATION AND ROTATION TO ENSURE IMAGE CONSISTENCY AS THE PLAYER MOVES IN THE GAME.

9. S PECIAL EFFECTS P AGE 220 W AVE S URFACES W AVE SURFACES MAY BE SIMULATED WITH SIMPLE TRIG FORMULAS. T HE DISPLACEMENT OF A SURFACE AS A SINGLE WAVE PASSES BY : S UMMING OVER SEVERAL SUCH EQUATIONS YIELDS THE DISPLACEMENT AS MULTIPLE WAVES PASS BY

10. S PECIAL EFFECTS P AGE 221 S UBDIVISION S URFACES A N ALTERNATIVE TO DOWN - SAMPLING MESHES IS TO START WITH A LOW - RESOLUTION MODEL AND USE CUBIC SPLINES TO GENERATE A MODEL WITH HIGHER RESOLUTION. E ACH OF THESE MODELS BEGAN WITH A RELATIVELY UNDETAILED MODEL CONTAINING KEY VERTICES, THAT WAS RECURSIVELY SUBDIVIDED UNTIL ACCEPTABLE RESOLUTION WAS ACHIEVED.

11. S PECIAL E FFECTS P AGE 222 P ELTING S UBDIVISION SURFACES LEND THEMSELVES TO “ PELTING ”, WHEREBY A 3-D MODEL ’ S SURFACE IS “ SKINNED ” AND THEN TEXTURE MAPPED TO A LINEAR GRID THAT HAS BEEN SUBDIVIDED TO AN ACCEPTABLE LEVEL OF DETAIL. A LIEN P ELT T EXTURE 6500-P OLYGON R ENDERED A LIEN