5. Lighting & Shading

Transcription

1 3 4 Rel-Worl vs. eg Rel worl comlex comuttos see otcs textoos, hotorelstc reerg eg smlfe moel met, ffuse seculr lght sources reflectos esy to tue fst to comute ght sources ght reflecto ght source: Reflecto (mterl): ghtg eg Gflot lght_os[] = {x,y,z, }; Gflot lght_[] = {R, G, B, A}; Gflot lght_[] = {R, G, B, A}; Gflot lght_s[] = {sr, sg, sb, sa}; glghtfv(g_ght0, G_PST, lght_os); glghtfv(g_ght0, G_AMBET, lght_); glghtfv(g_ght0, G_DFFUSE, lght_); glghtfv(g_ght0, G_SPECUAR, lght_s); Gflot mterl_k[] = {R, G, B, A}; Gflot mterl_k[] = {R, G, B, A}; Gflot mterl_ks[] = {sr, sg, sb, sa}; glmterlfv(g_frt, G_AMBET, mterl_k); glmterlfv(g_frt, G_DFFUSE, mterl_k); glmterlfv(g_frt, G_SPECUAR, mterl_ks); glmterlfv(g_frt, G_SHESS, Se);

2 5 7 8 ght Posto Posto worl-coortes ght sttory gluooat(eyex, eyey, eyez, ceterx, cetery, ceterz, ux, uy, uz); glghtfv(g_ght0, G_PST, os); Posto cmer-coortes ght movg wth cmer (helght) glghtfv(g_ght0, G_PST, os); gluooat(eyex, eyey, eyez, ceterx, cetery, ceterz, ux, uy, uz); Dffuse Reflecto Drecte lght Reflecto eeet o oretto of surfce lght source osto eeet of cmer osto (reflecte eqully ll rectos) Reflecte testy: = cos θ = ( ) θ Amet ght Scere y evromet Comg from ll rectos Reflecto eeet of Cmer osto ght osto (o lght osto) Surfce oretto Reflecte testy: = lght source mterl rmeter 6 Two Rt Surfce Ptches llumto B [lux] F B = A

3 Dffuse Reflecto Dffuse reflecto scles wth gle θ 90-θ A A / cosθ Surfce Surfce A/ F B = = cos θ cos F θ A llumto 9 Atteuto Qurtc euto ue to stl rto f = A moel ofte use Grhcs (eg) f = m (, ) c + c c + 3 glghtf(g_ght0, G_CSTAT_ATTEUAT, c); glghtf(g_ght0, G_EAR_ATTEUAT, c); glghtf(g_ght0, G_QUADRATC_ATTEUAT, c3); clue euto = ( ) A Smle Moel Sum u met lght ffuse reflecto: = + ( ) 0 Wvelegth Deeecy Colore lght reflecto s fuctos of wvelegth = ( ) Restrcto to RGB (eg) R G B = = = R G B R R R R G B R G B ( ) ( ) ( ) Restrcto of sectrl smlg to RGB c le to susttl color rtfcts

4 f f f s Deth Cueg (Fog) er eth cue y leg wth the color of the rtctg meum = s + ( s) c S 0 s sclg fctor (sgmol fucto) (z z )(s s ) s = s + z z for z z z s f Scle fctor s z Deth z f z 3 Reflecte Ry Comute usg smle vector lger S S R cosθ θ θ α V R = cos θ + S R = cos θ = ( ) cos α = R V = ( ( ) ) V 5 Seculr Reflecto Dees o gle etwee reflecto vewg ry R θ θ α V 4 Phog llumto Moel Aroxmtes seculr reflecto y cose owers = [ ( ) + ( R V ) ] 6

5 s s s s Amet + Dffuse + Seculr Amet Dffuse Seculr 7 Hghlghts s/ etermes hghlghte surfce regos 9 Extesos Seculr colors = [ ( ) + ( R V ) ] Hlfwy-Vector (fster) cos β = ( H ) H = + V + V β H θ θ α R V Multle ght Sources = [ ( ) + ( R V ) ] m 8 ght Sources Drecte Sotlghts Sot osto γ ' cos ' ( ') Sot recto glghtfv(g_ght0, G_SPT_DRECT, ); glghtf(g_ght0, G_SPT_EXPET, ); 0

6 testy Dgrms mlemete most moer grhcs APs Shg Moels Flt shg (costt shg) oe color er rmtve Gouru shg ler terolto of vertex testes Phog shg ler terolto of vertex ormls Gouru & Phog shg ee vertex ormls 3 Shg Shg requres my evlutos of lghtg moel Questos: where to evlute? whe to evlute? Gouru Shg Proceure. Clculte fce ormls. Clculte vertex ormls v = = = 3. Evlute lghtg moel for ech vertex 4. terolte vertex testes cross rmtve (ler terolto) 3 4 v 4

7 Gouru Shg terolto er terolto o curret sc le y y = -( - ) (y -y s ) (y -y ) y s y y 3 Sc le Doe urg sc coverso Hrwre ccelerto ossle 3 x = -( - 3 ) (y -y s ) (y -y 3 ) = -( - ) (x -x ) (x -x ) 5 Phog Shg er terolto of ormls (ot testes) o curret sc le 0 c P 0 P P P c P Evluto of lghtg moel t ech xel More ccurte ut slower th Gouru 7 Gouru Shg Qulty Shg qulty ees o sze of rojecte rmtves (reltve to xel sze) 6 Shg Methos vervew Shg mge sce: Flt shg (Costt shg) Gouru shg Shg oject / scree sce: Phog shg mct o grhcs hrwre... 8

8 Trsrecy Trsrecy oe wth α-leg erzg exoetl euto of testy me P P t thcess vew α α = (oque) α: sorto 9 Trsrecy Bsc ws P flters testy ccorg to ' α t = e erzto yels ' = ( α t) Emsso of P ' = α t Summg u (for ut legth) = ' + ' = α + ( α ) For olygos (α-leg ) = α ( α ) = = 30