Daim Duab 3D nrog AutoCAD - Tshooj 8

TSHOOJ 39: MALLAS

Meshes yog 3D cov khoom tsis muaj lub cev xws li khib nyiab. Lawv paub qhov txawv ntawm qhov chaw vim lawv raug tsim los ntawm ib pawg ntsej muag uas sib dhos ua ke los ntawm kev sib tshuam thiab cov npoo. Lawm, txhua lub ntsej muag yog tsim los ntawm kev daws teeb meem ntawm kev sib tw uas txiav txim xyuas nws cov kev sib tsoo. Cov ntsej muag ntawm cov meshes, ib tus zuj zus lossis tag nrho, muaj peev xwm nce lossis txo cov xov tooj ntawm cov txheej txheem lawv muaj, yog li ntawd qhov kev sib tw nce lossis txo qis. Ntawm qhov tod tes, cov ntsej muag tuaj yeem fused nrog lwm cov ntsej muag lossis txawm subdivided, uas yog, lawv tuaj yeem tig mus rau hauv cov ntsej muag cov txheej txheem uas tsim nws, uas ua rau lawv cov kev sib hloov ntawm kev sib tsoo. Txawm li cas los xij, qhov taw tes ntawm qhov kev ua tiav ntawm qhov kev pab cuam tuaj yeem ncav tau, vim muaj ntau lub ntsej muag (thiab cov no tig ntawm ntau yam kev sib tw) ntawm cov khoom mesh nws muaj.
Qhov tseeb, cov khoom ntawm mesh khoom (lawv cov ntsej muag, cov ntsej muag thiab kev ua haujlwm) yog cov uas zoo tshaj plaws rau lawv, raws li nws yog ib qho uas yuav hloov cov khib nyiab thiab cov sab nraud rau cov khoom ntawm hom no tsuas nrog lub tswv yim ntawm kev sib tsoo lawv.
Tab sis wb tuaj saib seb yuav tsim cov khoom siv mesh li cas thiab mam li tawm mus rau ib qho kev hloov kho.

39.1 Meshes los ntawm cov khoom yooj yim

39.1.1 Mesh txhais los ntawm ob tog

Peb tuaj yeem tsim ib lub mesh uas yog bounded los ntawm kab, arcs, polylines, los yog splines, tsuav yog lawv txhais ib cheeb tsam kaw los ntawm kev sib koom lawv cov ntsiab lus kawg. Nws yog qhov peb hu ua "Mesh txhais los ntawm ob sab".
Qhov kev daws teeb meem ntawm cov mesh yog txhais los ntawm tus nqi ntawm ob qhov sib txawv ntawm Autocad: Surftab1 thiab Surftab2, uas nws tus nqi pib yog 6. Yog tias koj sau cov kev hloov pauv no hauv lub qhov rais hais kom ua, koj tuaj yeem nce lossis txo lawv cov nqi, uas yuav cuam tshuam rau tus lej. ntawm lub ntsej muag ntawm cov meshes tshiab (tsis yog hauv cov uas twb tau piav qhia lawm). Pom tseeb, nrog tus nqi siab ntawm cov kev hloov pauv no, qhov tseeb thiab "smoothness" ntawm qhov chaw yog ntau dua, tab sis yog tias lawv dhau los ua nyuaj lawv tuaj yeem cuam tshuam rau lub sijhawm rov tsim dua tshiab ntawm cov khoom ntawm lub vijtsam nyob ntawm qhov ceev thiab nco ntawm koj lub computer.
Txawm li cas los xij, tsis hais tus nqi peb muab rau cov qhob no, peb yuav pom ntev li cas ua kom qhov kev ua siab zoo ntawm hom khoom no.

39.1.2 Regladas

Tus mesh tswj yog zoo ib yam li ib qho dhau los, tab sis tsuas yog yuav tsum muaj ob yam khoom uas ua haujlwm. Yog li tsuas yog tus npoo ntawm M yog kos thiab nws qhov kev daws teeb meem yog muab los ntawm tus nqi ntawm Surftab1, qhov nqi ntawm lwm qhov txawv txav tsis cuam tshuam li cas.
Cov khoom uas txhais tau ntawm cov nplaim yuav yog cov kab, cov voj voog, cov hlua khau, ellipses, polylines thiab splines nrog rau kev sib koom ua ke ntawm cov khoom kaw los yog khub ntawm cov khoom qhib, cov khoom tsis yog siv.
Thaum siv cov khoom qhib, nws yog qhov tseem ceeb uas yuav tsum nco ntsoov lub ntsiab lus ntawm qhov khoom tau taw qhia, vim hais tias qhov kev txiav txim nrhiav qhov kawg qhov taw tes kom pib qhov chaw ntawm qhov ntawd. Hais tias yog, yog hais tias tawm tsam ntsiab lus yog taw tes, lub saum npoo yuav ua rau nws tig.

39.1.3 Tabulated

Tabulated meshes yog generated ntawm ib qhov profile thiab ib txoj kab uas ua hauj lwm raws li vector ntawm kev coj ua thiab qhov dav. Hauv lwm lo lus, peb tuaj yeem tsim qhov profile ntawm cov khoom siv nrog cov kab, cov hlua, polylines lossis splines thiab ces tsim ib qho kev rho tawm ntawm qhov profile ntawd. Qhov loj me thiab kev coj ntawm lub extrusion yog muab los ntawm lwm txoj kab ncaj nraim uas ua hauj lwm ua ib qho vector. Raws li peb tau rov los xyuas cov extrusions ntau zaus, tsis muaj ntau ntxiv rau hauv no hwm, tsuas yog dab tsi yog qhov yuav tsum tau ua piv txwv rau cov ntaub ntawv no hauv cov yees duab nram qab no.

39.1.4 Revolutionized

Revolutioned meshes yog generated los ntawm ib qho profile ntawm ib qho axis, yog li tsim lub ntsej muag ntawm lub mesh. Qhov profile hu ua trajectory nkhaus, lub axis, axis ntawm lub kiv puag ncig, uas yuav tsum yog ib txoj kab lossis thawj kab ntu ntawm cov polyline. Los ntawm kev ua neej, qhov profile tig qhov 360 degrees, tsim ib qho khoom kaw 3D, tab sis peb tuaj yeem qhia pib thiab xaus lub kaum ntse ntse, uas tsis tas yuav tsum yog 0 thiab 360 degrees.
Raws li koj yuav nco ntsoov, qhov txhais ua ntej siv qhov zoo tib yam rau cov khib nyiab thiab qhov chaw ntawm lub kiv puag ncig, yog li, dua, nws tsuas yog ua yam ntxwv ntawm ib qhov profile.