Visualization and 3D Graphics

Weiguang Guan

RHPCS, ABB 131-G Email: [email protected] Phone: 905-525-9140 x 22540 Outline

■ OOvverervviewiew ■ IInnttrroodduuccttioionn ttoo 33DD ggrrapaphhicicss anandd vvisuisualizalizatatioionn ■ OOppenenGGLL ■ VVTTKK (V(Visuisualizalizatatioionn TToooolkitlkit)) Overview

■ GGooal:al: KKnnoowledwledggee anandd skillskill ttoo vvisuisualizalizee rresearesearcchh ddatataa ooff vvararioiouuss foforrmmss ■ CoConnttenentt:: 33DD ggrrapaphhicicss pprrooggrramaminingg uusinsingg ◆ OOpepenGnGLL (low-(low-lelevveell graphicgraphicss llibraribraryy)) ◆ VVTTKK ((HHigigheherr-le-levveell ggrraaphicphicss liblibrraryary)) ■ PPrrelimelimininararyy knknoowledwledggee ◆ C/CC/C++++,, ttccll//ttkk ◆ BBaassiicscs ooff ccomomputputeerr ggrraapphhicicss ✦ 3D3D tratrannssfformormaatitionon ✦ IIlllumlumininaatitionon mmododeell Overview

■ WWebeb rresoesouurrcceses ◆ www.www.ooppeengngl.orgl.org ◆ www.www.vtvtkk..orgorg ◆ www.www.ccmmaakkee.or.orgg ■ BBooooksks ◆ CoCommputputeerr GGrraaphicphics,s, PriPrinnccipiplleess andand PrPraacctticicee,, SSeeccoonndd EEddititiionon,, JaJammeess D.D. FFooleleyy,, eett al,al, AAddisoddisonn WWeessleleyy,, 11999900.. ◆ TThehe OpeOpennGGLL PrProogramgrammmiingng GGuuiidede -- TThhee RReedbookdbook,, ffiifftthh eeddiittioionn.. Overview

◆ TThehe OpeOpennGGLL RReeffeererennccee MMaannuualal -- TThehe BBllueuebbooook,k, ffourtourthh eeditditiionon ◆ TThehe VViissualiualizatzatiionon TToolkioolkitt:: AAnn OObjbjeecctt-- oorrieienntteedd AApppprroacoachh ttoo 33DD GGrapraphhicics,s, 33rdrd eeddititioionn.. ◆ TThehe VViissualiualizatzatiionon TToolkioolkitt UUsseerr’s’s GGuuididee ■ SScchhededuulele (6(6wkwk xx 33)) == 1188 hhoouurrss ◆ OOpepenGnGLL (3(3wwkk xx 33 == 99 hhoouursrs)) ◆ VVTTKK ((33wkwk xx 33 == 99 hhoouurrss)) ◆ LLeeccttuurree--ttoo-la-labb ratratiioo 11::44 ◆ 66 pprrojojeeccttss ((6600%%)) ++ ffinalinal eexaxamm (4(400%)%) Introduction to 3D Graphics and Visualization

Weiguang Guan

RHPCS, ABB 131-G Email: [email protected] Phone: 905-525-9140 x 22540 Outline

■ EExxamampplesles ooff vvisuisualizalizatatioionn/3/3DD ggrrapaphhicicss ■ 33DD ggrrapaphhicicss pprrimimerer ■ VVisuisualizalizatatioionn pprrimimerer Examples of visualization/3D graphics W i r e f r a m e Examples of visualization/3D graphics S h a d e d

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■ WWhathat isis ccomomputputeerr graphicgraphicss tratrannsfsformsorms ggrarapphhiicscs ppririmimititivevess ((ppoioinnts,ts, lliinnees,s, ppololygygonons,s, eetctc)) iinntoto ppiicturecturess oror aannimaimattionionss ■ EEsssseentntialsials inin 33DD graphicgraphicss 3D Graphics Primer

◆ 33DD scescennee ((ccomompposeosedd ofof obobjjeecctsts)) ✦ Geometric shape/location//ooriienntaation ✦ Surface material properties (ambient, diffuse, specular, shininesss,, emission)) ◆ LLigighhtsts ((ononee oror mmoreore)) ✦ Point light source (position, ammbiieennt, diffuse, specular, etc) ✦ Spot light source (+ spot direction, spot cut-off, etc) ✦ Parallel light source (distant point llight source) ✦ Ambient light (contained in pooiint//sspot light sources) ◆ VVieiewweerr ✦ Position ✦ Orientation ✦ Upwarrdd direction 3D Graphics Primer

■ 33DD ttrranansfosforrmmatatioionn ◆ SSccaalingling [[x’x’,, y’y’,, zz’’]]t == ss [[x,x, y,y, zz]]t ◆ RRototaattionion t t [[x’x’,, y’y’,, zz’’]] == RR3x3 [[x,x, y,y, zz]]

wwhheerere RR3x3 iiss aann orthorthogogononaall mamatritrix.x. ◆ TTranransslalattionion [[x’x’,, y’y’,, zz’’]]t == [[x,x, y,y, zz]]t ++ [[ddx,x, ddy,y, ddzz]]t 3D Graphics Primer

◆ HHomomogogeenneeousous coordcoordiinnaatteess [x, y, z]t [x, y, z,, 1]]t [wxx, wwy, wzz,, w]t ◆ UUnnififiieedd tratrannssfformaormatitionon t t [w’x’, w’y’, w’z’’, ww’] = MM4x4 [wx, wy, wz, w] ✦ Scaling ✦ Rotation s 0 0 0 0 s 0 0 a b c 0 MS = 0 0 s 0 d e f 0 MR = 0 0 0 1 g h i 0 0 0 0 1 ✦ Translation 1 0 0 dx 0 1 0 dy MT = 0 0 1 dz

0 0 0 1 3D Graphics Primer

◆ TTranranssffoorrmmaattionion ccomombbinatinatiioonn OOrdrdeerr ofof tratrannsfsformaormatitiononss mamattettersrs

Rotaation Translation Translation Rotation

MM = MMT MMR MM = MMR MMT 3D Graphics Primer

■ Illumination model Illumination model Rac Rdc Rsc (Phong’s(Phong’s)) α - cos α cos α

Rc = Rac + Rdc + Rsc + β - - sin ββ

Ec wwhheerere c =r, g,, bb a: ambient d: diffuse α s: specular β R: reflected lighht E: Emitted lligghtt 3D Graphics Primer

■ CamCameerara MModeodell ◆ EEyeye CCoordoordininaatete ◆ FFrustumrustum systesystemm ✦ Left/Right ccllipppingg ✦ Position planes ✦ ✦ Orientation Bottom/Top clipping planes ✦ Upwarrdd direction clipping planes ✦ Near/Far clippiingg planes 3D Graphics Primer

■ RReendenderingring ◆ PosPositiitiononiningg obobjjeecctsts iinn 33DD sspapaccee ◆ CClliippppiinngg ◆ MMaappppiinngg onontoto vivieewwpportort ◆ RaRastesterrizizaatitionon aanndd aanntiti--aalliiaassiinngg 3D Graphics Primer

■ FFramrameebufbufffeerr ◆ CCololoror bbufufffeerr ((sisinngglele oror ddouboubllee)) 5 5 5 5 5 5 5 5 ◆ 5 5 5 5 5 5 5 5 DDeepthpth bbufufffeerr ((oror zz--bbufufffeerr)) 4 4 4 4 4 4 4 4 2 2 2 2 2 2 2 2 Depth 2 2 2 2 2 2 2 2

1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Red, Green, 0 0 0 0 0 0 0 0 Blue 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Visualization Primer

■ WWhhatat isis vvisuisualizalizatatioionn ttransransfformormss datdataa intintoo graphicgraphicalal primprimititiveivess ■ WWhhyy vvisuisualizalizatatioionn TToo pepercrceeiveive andand undeundersrsttandand ssttrucructtureuress ccontontaaiinenedd iinn datdataa ■ TTerermmininoolologgyy ◆ DaDattaa vviissualiualizatzatiionon ◆ SScciieennttifificic vvisisualiualizatzatiionon ◆ InfInformormatatiionon visvisuauallizizatatioionn Visualization Primer

■ MMuultlti-di-disciscipiplinlinararyy fieldfield ◆ CoCommputputeerr ggrraphaphicicss GGeeomeometritricc ddeescriscripptitionon rerennddeereredd iimamaggeess ◆ ImImaagiginngg ReReaall wworlorldd ssaampmplliinnggss ofof curtacurtaiinn ppropropeertirtiees,s, ee..gg.,., aabbsorpsorptitionon ofof x-x-rarayy inin CCTT imaimaggiinngg,, protonproton ddeennsitysity inin MMRRII,, vevellociocity,ty, mmomomeenntumtum,, phphoto-oto-raraddiioaoactivictivittyy,, eetctc ◆ CoCommputputeerr vivissioionn IImamaggeess ((pphhotos)otos) GGeeomeometritricc ddeescriscripptitionon Visualization Primer

■ DDatataa ttoo bbee vvisuisualizalizeded ◆ GGeeoommeettricric datdataa PoiPoinnt,t, lliinnee,, curvecurve,, ppololygygonon,, curvecurvedd surfsurfaacece ◆ DisDisccrerettee ssamamplepledd datdataa ffrroomm dedevvicicee oorr sisimmuullatatiioonn ✦ DimDimeennsionsionaallity:ity: 11DD,, 22D,D, 3D3D ++ titimeme ✦ SSaampmplliningg toptopologology:y: structurestructuredd/un/unstructurestructuredd ✦ SSaampmplliningg ggeeomomeetry:try: rereggululaarr,, rerectictilliinneeaar,r, ccurvilurvilinineeaarr ✦ NNuumbmbeerr ofof qquauanntitititiees:s: ssccaalalarr ((11)),, vevectorctor ((>1>1)),, tetennssoror ((99)) Visualization Primer

■ VVoolulummee vvisuisualizalizatatioionn ------vvisuisualizalizatatioionn ooff 33DD ararrrayay ooff ddatataa ◆ VVoollumumee rreennddeerinringg:: vvolumolumee vvieiewewedd asas ttransranslucluceenntt gegell tthahatt eemmititss andand oocccclludeudess liligghhttss.. ✦ IInnteternrnaall strstrucucturtureess aarere ddiissplaplayeyedd ✦ DifDifffiicultcult toto ununddeerrstastanndd ◆ SSururfacfacee rreendndeeringring:: eexxttraractct ssurfurfacaceess ffromrom vvolumolumee,, tthehenn applapplyy ttraditraditiionalonal ccomomppututeerr ggrraphiaphicscs tteecchhnniiqueque ttoo dispdisplalayy tthehemm.. ✦ OOnnllyy surfsurfaacecess aarere ddispispllaayyeedd ✦ EEaasysy toto ununddeerrstastanndd Visualization Primer

■ VVoolulummetetrricic ddatataa GGeoeommetetrricic ddatataa IsIso-o-ssurfurfacacinging algoritalgorithmhm tthathat eextxtracracttss susurrfacfacee iinn aa voluvolummee dedeffiinneedd byby anan isiso-o- valuvaluee ■ GGeoeommetetrricic ddatataa VVoolulummetetrricic ddatataa VVoxeoxelizlizatation,ion, aa procproceessss ttoo disdisccrerettizizee aa gegeoommeettrriicc ddeessccrriiptptiionon.. TThhee EEnndd ooff InInttrroodduuccttiioonn ttoo 3D3D GGrraapphhiiccss aanndd ViVissuuaalliizazattiioonn