pture imges mesuring devie Digitl mers mers fill in memor ith olor-smple informtion D hrge-oupled Devie insted of film film lso hs finite resolution grininess depends on speed IS 00 00 6400 sie 35mm IMAX et Importne of mer models Understnding mers llos: Using photogrphs of rel orld for modeling nd rendering Rendering 3D senes hih is euivlent to tking pitures of the virtul orld
lnr pinhole mer model inhole lso lled enter of projetion point of onvergene of ll inoming rs 3 lnr pinhole mer model Imge plne plne here interseting inoming rs rete the olor smples piels of the imge defined non-prllel vetors nd u v 4
lnr pinhole mer model oint nd vetors define generl plnr pinhole mer 5 Speil pinhole mer model K to ssume tht vetors nd re perpendiulr sure piels nd sme length projets in the enter of the imge plne 6 3
4 7 onstrutor Hflot hfov int int h hfov is the horiontl field of vie [degrees] is the idth of the imge [piels] h is the height of the imge [piels] / tn 000 0 0 00 hfov h 8 rojetion of points u v [ ] v u v u v u v u v u 0 0 < 0 no projetion > 0 vlid projetion
lipping left of vie frustum test u < 0 ove vie frustum test v < 0 ehind suvolume right of vie frustum test u > idth test < 0 elo of vie frustum test v > height 9 iel oordintes iel u v hs enter t.5fflotu.5fflotv The imge strethes from 0.0f to flot nd from 0.0f to floth A ro hs piels: piel 0 - A olumn hs h piels: piel 0 h- An imge point uf vf uf nd vf re flots elongs to piel int uf int vf 0 5
ther mer methods Aess Get vie diretion fol length Get r piel enter Get horiontl / vertil field of vie Get prinipl point piel oordintes of projetion onto imge plne Nvigtion Trnsltion left-right up-don forrd-krd Rottion left-right pn up-don tilt pith sides roll Revolve horiontll round point thet degrees Revolve vertill round point thet degrees ositioning le mer suh tht it looks t point from distne d nd hs up vetor up Internl prmeters hnge Zoom in-out hnge of field of vie hnge of resolution ropping/etensions Vie interpoltion Give H 0 nd H rete N mers tht smoothl hnge the vie from H 0 to H Aess Get vie diretion vd.unitvetor Get fol length f vd* Get r for piel u v -- integers ru v *u0.5f*v0.5f Get r for piel imge point uf vf -- flots ruf vf *uf *vf Get piel enter -- integers u v ru v Get horiontl field of vie hfov *tn/*.length/f // ssumes projets t / Get prinipl point imge oordintes of projetion u -*.UnitVetor/.Length v -*.UnitVetor/.Length 6
7 3 Trnsltions step UnitVetor krd forrd step UnitVetor don up step UnitVetor right left *. *. *. Trnsltion right 4 Rottions : :... θ θ θ θ θ RotteAout Roll RotteAout Tilt RotteAout RotteAout RotteAout n n
mer positioning le mer suh tht it looks t point from distne d hs vie diretion vd nd up is vetor in the vertil plne of the mer // ssumptions: retngulr piels up nd vd re normlied vd*d vd up.unitvetor*.length vd.unitvetor*.length u * v * vd*f up vd d 5 Zooming Fol length hnges: f f * oom - u * v * vd*f _ f _ f 6 8
More or feer piels; *k h h*k nd do not hnge *k nd h hnge uffers hve to e relloted hnge of resolution 7 ropping/etensions Set the imge to retngle u 0 v 0 u v u 0 * v 0 * u -u 0 h v -v 0 u 0 v 0 u v 8 9
Vie interpoltion Given H 0 nd H rete N intermedite mers Assumption: H 0 nd H hve the sme internl prmeters i 0-0 *floti/flotn- vd i vd 0 vd -vd 0 *floti/flotn- i 0-0 *floti/flotn- See mer positioning 9 Rel orld mer models Aperture is finite depth of field onl ojets t ertin distne re in fous Lens distortion stright lines re urved in the imge rrel pinushion 0 0
Thin lenses rs through lens enter do not hnge diretion rs prllel to optil is go through fol point F nl ojets t ertin depth re in fous Depth of field imge F F perture ojet