viewing perspective projection in drawing

Transcription

1 viewig compue gaphics viewig 28 abio pellacii 1 pespecive pojecio i dawig [Masche 24 oigial ukwo] compue gaphics viewig 28 abio pellacii 2

2 pespecive pojecio i dawig pespecive was o used uil cica 15h ceuy echical explaaio by Leo Baisa Albei 1436, De Picua Della Piua Tovai aduque io queso modo oimo cosi i ue le cose seguedo quao dissi, poedo il puo ceico, aedo idi liee alle divisioi della giacee liea del quadagolo. compue gaphics viewig 28 abio pellacii 3 [ , Gioo] compue gaphics viewig [Web Galey o A, pespecive pojecio i dawig 28 abio pellacii 4

3 [ , Masaccio] compue gaphics viewig [Web Galey o A, pespecive pojecio i dawig 28 abio pellacii 5 [Masche 24 oigial ukwo] pespecive pojecio i phoogaphy compue gaphics viewig 28 abio pellacii 6

4 pespecive pojecio i phoogaphy [Richad Zakia] compue gaphics viewig 28 abio pellacii 7 ayacig vs. pojecio i ay acig: image plae objec poi sa wih image poi geeae a ay deemie he visible objec poi i pojecio: objec poi image plae sa wih a objec poi apply asoms deemie he image plae poi i pojecs o ivese pocess compue gaphics viewig 28 abio pellacii 8

5 viewig map 3d wold pois o 2d image plae posiios wo sages viewig asom map wold coodiaes o camea coodiaes chage o coodiae sysem pojecio map camea coodiaes o image plae coodiaes ohogaphic o pespecive compue gaphics viewig 28 abio pellacii 9 viewig asom ay aie asom useul o deie oe o ou viewe model deied by oigi, owad, up compued by ohoomalized ame om he vecos cosuc a maix o a chage o cood. sysem see i pevious lecue compue gaphics viewig 28 abio pellacii 1

6 pojecio i geeal, ucio ha asoms pois om m- space o -space whee m> i gaphics, maps 3d pois o 2d image coodiaes excep we will keep aoud he hid coodiae compue gaphics viewig 28 abio pellacii 11 caoical view volume he esul o a pojecio eveyhig pojeced ou o i will o be edeed (x,y) ae image plae coodiaes i [-1,1]x[-1,1] keep aoud he z omalized i [-1,1] deie a ea ad a disace eveyhig o he ea plae has z=1 eveyhig o he a plae has z=-1 iveed z will become useul lae o compue gaphics viewig 28 abio pellacii 12

7 caoical view volume why ioducig ea/a clippig plaes? mosly o educe z age, moivaed lae compue gaphics viewig 28 abio pellacii 13 axoomy o pojecios Plaa Geomeic Pojecio Paallel Pespecive Ohogaphic Oblique Oe poi Two pois Thee pois Top, Fo, Side, Axoomeic, Oblique Cavalie Ohe compue gaphics viewig 28 abio pellacii 14

8 axoomy o pojecios Plaa Geomeic Pojecio Paallel Pespecive Ohogaphic Oblique Oe poi Two pois Thee pois Top, Fo, Side, Axoomeic, Oblique Cavalie Ohe compue gaphics viewig 28 abio pellacii 15 axoomy o pojecios Ohogaphic Oblique Pespecive compue gaphics viewig 28 abio pellacii 16

9 ohogaphic pojecio box view volume compue gaphics viewig 28 abio pellacii 17 ohogaphic pojecio viewig ays ae paallel compue gaphics viewig 28 abio pellacii 18

10 compue gaphics viewig 28 abio pellacii 19 ohogaphic pojecio ceeed aoud z axis = ) ) /( (2 / / z y x z y x compue gaphics viewig 28 abio pellacii 2 ohogaphic pojecio wie i maix om 1 ) ) /( ( ) 2 /( 1/ 1/

11 pespecive pojecio ucaed pyamid view volume compue gaphics viewig 28 abio pellacii 21 pespecive pojecio viewig ays covege o a poi compue gaphics viewig 28 abio pellacii 22

12 compue gaphics viewig 28 abio pellacii 23 pespecive pojecio ceeed aoud z axis =... ) ) /( ( ) ) /( ( z y z x z y x compue gaphics viewig 28 abio pellacii 24 pespecive pojecio wie i i maix om use homogeeous coodiaes, sice w 1 1 ) /( 2 ) ) /( ( / /

13 pespecive pojecio ohogaphic pojecio is aie pespecive pojecio is o does o map oigi o oigi maps lies o lies paallel lies do o emai paallel legh aios ae o peseved closed ude composiio compue gaphics viewig 28 abio pellacii 25 moe o pojecios he give maices ae simpliied cases should be able o deie moe geeal cases o-ceeed widows o-squae widows ca id deivaio i he Shiley s book bu i is a simple exesio o hese oe ha sysems have diee coveios pay aeio a hei deiiio someimes ames ae he same compue gaphics viewig 28 abio pellacii 26

14 compue gaphics viewig 28 abio pellacii 27 geeal ohogaphic pojecio b b b l l l compue gaphics viewig 28 abio pellacii 28 geeal pespecive pojecio b b b l l l