Z buffer vs A buffer
Z tsis thiab Ib qhov tsis yog ob qho ntawm cov txheej txheem pom pom saum npoo nrov tshaj plaws siv hauv 3D computer graphics. Pom pom saum npoo (tseem hu ua kev tshem tawm qhov chaw zais) yog siv los txheeb xyuas qhov pom hauv qhov xwm txheej los ntawm qee qhov pom hauv lub ntiaj teb 3D. Muaj ob pawg tseem ceeb ntawm txoj kev tshawb pom saum npoo hu ua Object Space Methods thiab Image Space Methods. Object Space Methods suav nrog kev sib piv cov khoom thiab / lossis cov khoom siv los txiav txim siab seb qhov chaw twg pom. Image Space Methods cuam tshuam nrog kev txiav txim siab pom ntawm qhov taw tes-rau-taw tes ntawm qib pixel. Image Space Methods yog qhov nrov tshaj plaws thiab Z tsis thiab A tsis yog nyob rau hauv qeb ntawd. Z buffer method suav qhov qhov tob qhov tob rau txhua pixel thoob plaws qhov chaw. Ib txoj hauv kev tsis yog qhov txuas ntxiv rau Z tsis yog txoj kev, uas ntxiv qhov pom tseeb.
Z buffer yog dab tsi?
Z buffer txoj kev tseem hu ua qhov tob-buffer method. Z tsis yog ib qho raster tsis uas khaws cov ntaub ntawv xim thiab qhov tob rau txhua pixel. Lub "Z" hauv Z tsis yog hais txog lub dav hlau "Z" hauv 3 qhov chaw. Z buffer txoj kev kuaj pom qhov chaw los ntawm kev sib piv qhov tob qhov tob rau txhua pixel thoob plaws hauv qhov chaw ntawm lub dav hlau ntawm qhov projection. Qhov no feem ntau ua tiav hauv kev kho vajtse, tab sis qee zaum ua hauv software. Feem ntau, Z buffer txoj kev yog siv rau scenes tsuas yog ua los ntawm polygons. Z buffer txoj kev yog ceev heev vim hais tias qhov tob qhov tseem ceeb yuav xam tau yooj yim heev. Ib qho tseem ceeb tshaj plaws uas cuam tshuam qhov zoo ntawm cov duab ua tau zoo yog qhov granularity ntawm Z tsis. Cov granularity qis dua tuaj yeem ua rau muaj teeb meem xws li Z-sib ntaus sib tua (tshwj xeeb tshaj yog rau cov khoom ze heev). Piv txwv li, 16-ntsis Z buffers tuaj yeem tsim cov teeb meem no. 24-ntsis lossis siab dua Z buffers muab qhov zoo dua hauv cov xwm txheej no. A 8-ntsis Z tsis yog suav tias muaj qhov tsis sib xws tsawg dhau los ua qhov tseem ceeb.
Dab tsi yog dab tsi?
A tsis (tseem hu ua anti-aliased, cheeb tsam-nruab nrab, tsub zuj zuj buffer) yog qhov txuas ntxiv rau Z tsis. Ib qho kev tsis sib haum xeeb tau tsim los ntawm Pixar. Ib txoj kev tsis tuaj yeem siv tau zoo rau nruab nrab scale virtual nco computers. Tib algorithm siv los ntawm Z tsis yog siv nrog A tsis. Txawm li cas los xij, A tsis muab kev tiv thaiv aliasing ntxiv rau qhov Z tsis ua. Hauv Ib qho tsis, txhua pixel yog tsim los ntawm ib pawg ntawm sub pixels. Cov xim kawg ntawm ib pixel yog xam los ntawm kev suav tag nrho nws sub pixels. Ib tug tsis tau txais lub npe tsub zuj zuj tsis vim qhov tsub zuj zuj ntawm qhov chaw ntawm sub pixel theem.
Z buffer thiab A tsis yog dab tsi?
Z tsis thiab A tsis yog ob qho ntawm cov txheej txheem pom pom saum npoo nrov tshaj plaws. Qhov tseeb, A tsis yog qhov txuas ntxiv rau Z tsis, uas ntxiv kev tiv thaiv aliasing. Feem ntau, A tsis muaj cov duab daws teeb meem zoo dua Z tsis, vim tias nws siv lub qhov rais Fourier yooj yim xam tau. Txawm li cas los xij, A tsis yog tus nqi qis dua Z tsis.
