TRNG I HC KHOA HC T NHIN

3I.To m hnh nhn vt

3A.L THUYT POLYGON

7B.To c th

8C.To khung xng

9D.To o qun

11II.To chuyn ng

11A.To chuyn ng cho khung xng

11K thut IK (Inverse Kinematics)

12B.Gn khung xng vo c th

12C.Export, import trang phc v hon chnh nhn vt

121.Export trang phc

12Cch export o

12Cch export qun

132.Import v iu khin mu o

13M tp tin cha m hnh to chuyn ng

13Import o

13nh v tr cho mu o

14To i tng collision

14Gi lp

143.Import v iu khin mu qun

14Import v nh v mu qun

15To i tng collision cho mu qun

15Gi lp

164.iu khin cc solver

16Di chuyn solver ca mu qun n mu o

165.To li

16Thm li cho mu qun

176.iu chnh li trang phc

17iu chnh li mu o

17Tin hnh simulation cho mt lot chuyn ng

17Thm li cho mu qun

187.Lu trng thi khi to cho trang phc

18Lu trng thi khi to cho mu o v qun

19Tin hnh simulation cho chuyn ng i b

19III.Hot cnh v nh sng.

19A.Gii thiu rendering.

191.Quan st kt qu render.

192.im quyt nh thc hin render thnh cng.

20B.Cc loi rendering:

201.Render phn mm:

212.Render phn cng

213.Render dng vector:

224.Cch chn loi render:

22C.Camera

221.Nhn cnh thng qua camera v thc hin render qua camera.

222.Cc loi camera

233.Hiu ng m n do di chuyn v su ca vng quan st

244.Canh cc i tng trong khung nhn camera.

265.To v s dng camera.

28D.Chiu sng (lighting):

281.Cc khi nim trong chiu sng:

302.Cc loi ngun sng trc tip:

323.Chiu sng ton cc v hin tng caustisc

33E.nh bng b mt

331.Cc khi nim:

342.Shading networks:

363.Cc loi vt liu:

374.Cc loi Texture:

395.p texture v nh v texture.

41F.Thm m thanh vo hot cnh.

I. To m hnh nhn vt

A. L THUYT POLYGON

To v chnh sa polygons:

Nhn vt thc cht c to nn bi s ni ghp c quy tc ca nhiu Poligon. Thc cht poligon l nhng hnh ton hc vi nhiu gc ,cnh khc nhau.Nhng ng dng ch yu ch l cc hnh tam gic v hnh vung trong vic to hnh 1 nhn vt (cn c gi l m hnh li 3 v li 4 ).

Trong maya c nhng cng c to sn cc poligon chun : Create /Poligon Primitive v nhp chn nhng hnh thch hp vi cc thng s v chiu cao(heigh),bn knh(radus)ph hp.hoc c th to cc poligon vi nhng hnh theo mun :Poligon/create poligon tool,nhp chut v tng nh ca poligon mun to,nhn Enter hon tt vic to hnh . To hnh khng gian :chn mt cn y ,Edit polygons/Extrude face ,ko chut y hnh theo cc chiu khc nhau vi t l v s mt mong mun ,c th lm bng tay hoc nhp vo thng s trong Property y mt :Edit polygon/poke face ,cng c ny s y mt mt phng to thnh mt hnh chp gm nhiu mt phng cnh bn ,bng cch y ti tm ca hnh . Lm mn:cng c ny s t ng o gt nhng phn nh cao,nhng phn sc nhn ,vic lm ny s to ra nhiu mt i vi vt c lm mn .Chn phn cn lm mn ,Polygon/smooth hay Polygon/smooth proxy.chc nng sau cng ny s to ra hnh 2 bin th hnh lm mn Vt mt : chc nng vt mt gn ging nh chc nng lm mn nhng vic vt mt s to ra t mt hn v vn duy tr sc nhn ca vt th. .Chn mt cn vt Edit polygons/Bevel ,c th sa li thng s offset thay i vt mt

Trm l hng :chn tt c cc mt xung quoanh ,Edit Polygons/fill hole, chc nng ny s to ra mt mt phng da vo cc mt xung quanh ti v tr ch hng

B mt : Edit polygon /extract ,dng chut ly mt cn ly ra Lt mt : Edit polygon / normal/conform

nh x :Polygon/mirror ,to ra mt nh x vt th theo hng chn Chuyn i 1 NURBS sang polygon : Modify /convert / NURBS to polygons Chia mt :

C th dng mt trong cc cng c sau chia hoc ct mt:

-Edit polygons/split polygon tool:cng c ny c th c dng chia mt mt thnh nhiu mt theo mun bng cch s dng chut click vo v tr mun chia

trc khi chia (1 mt )

sau khi chia (4mt )

-Edit polygons/cut face tool : s ct ngang hnh theo mt chiu no

Ni :

chn cc hnh cn ni , polygon /combine -> chc nng ny dng ni cc b phn ring l ca c th li vi nhau

c th ni bng cch nhp cc im : Edit polygon/merge vertices ,y l mt chc nng kh mnh khi to hnh v chnh sa hnh da vo nhng nh ca nhng mt

trc khi trn

sau khi trn ngoi ra c th dng cc chc nng sau ni : Edit polygon/collapse hoc Edit polygon /normals/conform ni hnh m khng b vn c th ni theo thut ton boolean : Polygon /booleans

B. To c th to thn th :dng cc hnh lp phng c bn ,kt hp vi cc cng c y ,t l, chia mt,ni mt (cc cng c c bn trnh by phn l thuyt ) to ra m hnh c th nh mun to mt : dng cng c o cc m hnh NURBS bng cng c Edit NURBS/ sculpt surface tools .Trong to mt cn ch l cch lm tng s isoparamatric ri o ,cch ny s tng nt cho gng mtC. To khung xng

trc khi to khung xng cho c th th phi c m hnh da ca c th da vo m c t l xng v v tr xng cho thch hp vi tng nhn vt. Chn cng c to xng : Skeleton/joint tool ,trn thanh cng c bn phi mn hnh s hin ln biu tng xng,hy click vo v to nh to polygons,hy canh v tng v tr thch hp

chnh kich c xng : Windows/setting/references > reference ,chn size cho ph hp ,thng c khong 0.5 l ln

chnh li phn trm hin th xng cho thch hp : display/joint size /chn c

xng(joint chains) = khp xng (joint)+ on xng (bone)

khp xng gm 3 loi sau : ball joint ->l khp co th quay 3 hng, hinge joint ->l khp ch c th quay 1 hng duy nht ,khp cui cng l universal -> c th quay c c 2 hng

gn xng con vo xng cha ( v d nh ni khp ct sng vi xng cnh tay,hoc xng ct sng vi xng chn ) : Chn on xng con,+(shift)chn tip on xng cha , Skeleton / connection joint ->nhn connect

sau khi gn xng ,chn on xng con mun nh x (nh xng cnh tay v xng chn ) ,Skeleton /mirror ,chn trc i xng thch hp ->nhn miror.chc nng ny va to ra on xng nh x ,va gn n vo on xng cha nh l on xng con trc lm

Khi to xng cho nhn vt vic chn v tr t xng l rt quan trng ,nu t si v tr ,khung xng s khng ni phn da tht v chuyn ng ca nhn vt trng rt k d

C th xem li s xng va to trong : window/hypergraph

D. To o qun

Nguyn liu c bn ban u to thnh o qun l cc ng thng dng curve tung t nh ng ct o qun ,gm 2 mnh chnh nm trn hai mt phng trc v sau nhn vt (ch l cc ng curve thuc tng mnh phi nm trong cng 1 mt phng v phi to thnh hnh khp kn ) . Sau khi to xong cc ng curve c hnh nh bn di

May o qun : gm cc bc : + to khung panel t cc ng curve ( cloth / create panel ),mi khung s c 1 k hieu l

+ to li cho panel ( cloth / create garment )

+ may o qun (cloth / create seam ) ,may tt c nhng v tr cn ghp mnh li

+ r o qun

II. To chuyn ng

A. To chuyn ng cho khung xng

K thut IK (Inverse Kinematics)Gii thiu:

Phn ny gii thiu cch to cc IK handle to t th cho nhn vt.1. To IK handle cho chn: Chn Skeleton > IK Handle Tool>. Trong ca s Tool Settings, chn gi tr ikRPsolver cho Current Solver.

Trong perspective view, clik left_hip v left_ankle.

Hnh ng ny to mt IK handle cho php bn iu khin tt c cc im t left_hip n left_ankle. X l chnh ca handle l left_ankle.

Lu : Khng chn ng thi mt i tng no vi mt IK handle.

n frame u tin to chuyn ng.

Vi IK handle c chn, chn Animate > Set Key t kha cho v tr hin ti ca chn tri lc ny. n frame 12

Trong side view, dng cng c Move ko IK handle ln cao (xem hnh)

t kha cho IK handle v tr ny.

n frame 24, di chuyn IK handle v ch c. t kha cho IK handle ti thi im ny.

Tr v frame u chuyn ng v chi th.2. To IK handle cho tay:

To IK handle cho cnh tay tri:

i. Chn Skeleton > IK Handle Tool.

ii. Click chn theo th t left_shoulder, v left_wrist. To IK handle cho cnh tay phii. Chn Skeleton > IK Handle Toolii. Click chn theo th t right_shoulder, v right_wrist. B. Gn khung xng vo c thXng sau khi c to ch l mt m hnh c lp , cho xng v da tht to thnh th thng nht th ta phi buc xng vo vi c th : chn tt c da + xng ,dng cng c Skin /bind skin /smooth bind ->bind skin gn kt , v nu mun g rng buc ra ch cn dng skin /edit smooth skin / delete non- skin history . t y mi hot ng ca xng s ko theo s chuyn ng ca c th C. Export, import trang phc v hon chnh nhn vt

Gii thiu:

Phn ny gii thiu cch import mt b trang phc vo mt m hnh nhn vt to chuyn ng, hon chnh nhn vt.

Chi tit gm:

Cch export, import trang phc.

nh li v tr cho trang phc c import.

Cch s dng li gi cho trang phc v tr ng.

iu chnh cho trang phc va vn hn.

1. Export trang phc

Cch export o

3. M m hnhh shirtFinal.mb.

4. Chn mu o.

5. Chn File > Export Selection > . Ca s ty chn xut hin. Chn Edit > Reset Settings, nh du hp kim History. Click Export Selection.Khi hp kim History c chn, Maya export c iu khin trang phc(solver) ca tp tin shirtFinal.mb( y l iu khin ca mu o ). iu khin ny phi c export lun bi v bn cn dng n gi lp mu o s mi ln na bc import. Nu khng c d nh s dng li gi lp c, bn c th b nh du hp kim History.6. Trong ca s Export Selection, chn mi tn hng xung trn cng hin th menu ko th. Chn Current scences.7. nh tn shirtExport v click nt Export. Sau khi lm xong ta s c mt tp tin tn shirtExport.mb. Cch export qun

1. M tp tin tn pantsFinal.mb.

2. Chn mu qun.

3. Chn File > Export Selection > .4. Trong ca s Export Selection, chn mi tn hng xung trn cng hin th menu ko th. Chn Current scences.5. nh tn pantsExport v click nt Export. Sau khi lm xong ta s c mt tp tin tn pantsExport.mb.2. Import v iu khin mu o M tp tin cha m hnh to chuyn ng

1. M tp tin tn importStart.mb.

Ta thy m hnh nhn vt th ng chun. Khi bn import trang phc vo, c th phi nh li v tr nhn vt cho va vn vi trang phc.

2. nh li khong frame t -20 n 118.

3. Cho play scene.

Bn s thy t frame 20 n 1,nhn vt chuyn i t th t th ng chun sang th ng bt u chuyn ng.

4. Tr li frame u (-20).

Import o

1. Chn File > Import > . Trong ca s ty chn, chn Edit > Reset Settings, nh du hp kim User Namespaces, sau click Import.

2. Trong ca s Import Selection, click mi tn trong hp trn cng ca s hin th menu ko th v chn Current scenes.

3. Chnn shirtExport.mb v click Import. => Mu o c import.

4. Trong Outliner, chn shirtExort:shirt.

Trong Channel Box, cc tn shirtExport:cpSolver1 v shirtExport:cpStitcher1. Do cc ty chn ta chn ca s ty chn Import, Maya thm vo tip u ng shirtExport cho cc node cpSolver1 v cpStitcher1 ca tp tin shirtExport.mb. iu ny m bo tn l c nht, khng b trng vi cc tn trong scene hin ti. nh v tr cho mu o

1. Di chuyn v xoay o n va vn vi nhn vt. Smooth shading (nhn 5) thy c xuyn sut mu o.

bc ny khng cn phi lm cho mu o qu va vn vi m hnh. Hy tng tng khi nhn vt di chuyn th v tr o cng phi thay i. C th nh v tr theo nh s liu di y:

Translate X: 9.93

Translate Y: 0.1

Translate Z: -9.98

Rotate Y: -24

Trong Channel Box, click shirtExport:cpSolver1. Cho Start Frame bng -20 trong mc INPUTS hp Channel Box. Ci ny nh frame bt u gi lp.

Ch bn vn trong b menu Cloth, chn Simulation > Save as Initial Cloth State.

Maya s s dng v tr o hin ti v to hnh frame u tin to chuyn ng (frame -20).

To i tng collision

1. Chn m hnh nhn vt.

2. Chn Cloth > Create Collision Object.

3. Trong Channel Box, gn gi tr Collision Offset bng 0.16 v Collision Depth bng 0.2.

Khng cn quan tm n bo li Cycle on joint

Gi lp

1. Chn Simulation > Start Local Simulation.

o s t t r xung m hnh. Khi cm thy ng th nhn Esc.

3. Import v iu khin mu qun

Import v nh v mu qun

1. Giu mu o. (Tn ca mu o l shirtExport:shirt).

2. Chn File > Import ( tng t nh cch import mu o).

3. S dng cc s liu sau (nu mun):

Translate X: 10

Translate Y: 0

Translate Z: -10

Rotate Y: -30

4. Chn mu qun, click pantsExport:cpSolver1 trong Channel Box. t frame bt u l -20. Khi gi lp, hnh ng gi lp s bt u frame -20.

5. Chn Simulation > Save as Initial Cloth State

Maya s s dng v tr mu qun hin ti v to hnh frame u tin to chuyn ng (frame -20).Khi bn import mu o qun, Maya cng import lun cc solver. Tn ca cc solver l: pantsExport:cpSolver1, shirtExport:cpSolver1, c lit k trong menu Simulation > Solvers >.Lc ny, cc solver cha c tc dng no ln mu o qun v bn cha lin kt chng vi m hnh nhn vt trong scene ny.

By gi, bn s to cho m hnh nhn vt mt i tng collision( i tng iu khin va chm) tng tc vi mu qun trong sut qu trnh gi lp.

To i tng collision cho mu qun

1. Chn Simulation > Solvers >pantsExport:cpSolver1 to solver pantsExport:cpSolver1.

2. Chn m hnh nhn vt.

3. Chn Cloth > Create Collision Object.

4. Chn mu qun ch nh r solver bn mun s dng. Mc d shirtExport:cpSolver1 cha c tc dng g do n cha kt ni vi m hnh nhn vt nhng bn vn phi ch r l chn mu qun m bo thao tc l thc hin trn mu qun khi tin hnh gi lp.

Nu mt scene c nhiu hn mt solver, ti mt thi im ch c th thc hin thao tc gi lp cho mt i tng duy nht. Do , bn phi chn r solver mun thc hin.

Gi lp

1. Chn Simulation > Start Local Simulation.

Nhn Esc khi cm thy ng .4. iu khin cc solver

Mc ch:

to cho o s mi ph ln qun v khng ch m hnh nhn vt m c o qun cng c gn n solver

Di chuyn solver ca mu qun n mu o

1. Chn Simulation > Solvers > shirtExport:cpSolver1 to solver cho mu o.

2. Chn mu qun, chn Simulation > Transfer Garment.

Hnh ng ny dng di chuyn mu qun n solver ca mu o. xc nhn mu qun c iu khin bi solver ca mu o, nh du hp kim shirtExport:cpSolver1 trong phn INPUT ca Channel Box.

3. Trong Command Line, nh lnh: delete pantsExport:cpSolver1Lnh ny xa solver ca mu qun (v khng cn s dng n na) 5. To li

Mc ch:

m bo cho mu qun c nh v ph hp khi nhn vt di chuyn. Thm li cho mu qun

1. Chn m hnh nhn vt v chn Display > Object Display >Template.

2. Right-Click mu qun v chn Vertex.

3. Chn dng trn cng trong cc vertex ca mu qun. Nhn phm Shift thm( hoc b) cc vertive vo nhm chn la.

4. Trong Outliner, gi phm Ctrl v click vo ch mc jackie. Hnh ng ny thm m hnh nhn vt vo nhm chn la m khng b chn cc vertice.

5. Chn Constraints > Mesh to li. Biu tng li xut hin trn mu qun, ch ra v tr mu qun c rng buc vo m hnh nhn vt.

Giu biu tng mesh.

6. iu chnh li trang phc

Mc ch:

Cho o s mi ph ln qun. iu chnh li mu o

1. B chn mu m hnh nhn vt (untemplate).

2. Hin th mu o (show)

3. Giu m hnh nhn vt cho ri mt.

4. Chn mu (template) mu qun bn khng th thc hin thay i g trn n.

5. Right-Click con tr trn mu o v chn Vertex t menu ang c nh du.

6. Chn tt c cc nh(vertex) chng mu qun v mt nhnh nh cc nh khng chng ln mu qun. Nu khng th thy khu vc chng cch r rng, nhn 4 hin th wireframe, sau chuyn vo view.

7. Dng cng c Move v Scale di chuyn cc vertice ra khi mu qun.

8. Chn mu o v chn Simulation > Update Cloth State.

Hnh ng ny cp nht cho solver v tr mi ca cc vertice. Vic lm ny cn thit c th to gi lp chnh xc bc k tip.

9. Chn Simulation > Properties > shirtExport:cpPropertyShirt > . Ci t cc thng s: Thickness = 1.5 v Thickness Force = 3.5.Trng Thickness ch ra offset ca iu khin collision ca b trang phc n va chm vo nhau hay vo cc i tng qun o khc. Trng Thickness Force ci t mc p buc Maya s dng Tin hnh simulation cho mt lot chuyn ng

Mc ch:

Tin hnh simulation th ng thng thng bt u thc hin chuyn ng i b. Thc hin vic ny to ci nhn t nhin hn cho mu o qun trc khi thc hin chuyn ng i b. Thm li cho mu qun

1. Trong Time slider, t v tr u tin bng -20 v v tr kt thc bng 1.

2. Chn Simulation > Solvers > shirtExport:cpSolver1 >. Ci t gi tr cho cc thuc tnh sau: Start Frame: -20

Frame Samples: 2

Relax Frame Length: 0

Gi tr thuc tnh Frame Samples nh mc thng xuyn m solver thc hin nhng tnh ton ca qun o trong sut qu trnh simulation. Gi tr ny cng cao th cng chnh xc hn nhng thi gian x l s lu hn.

Mc nh, simulation l mt tin trnh gm 2 phn. Phn u, solver chnh va vn o qun cho nhn vt m khng c hiu ng g khc. Phn hai, chnh va vn o qun cng thm mt s hiu ng.

Gi tr thuc tnh Rax Frame Length ch nh di thi gian m Maya chnh va vn trang phc cho m hnh c th trc khi hiu qu ca cc hiu ng hiu qu khc th hin. Nhn chung, s frame cng ln th va vn s cng cao hn.3. Chn mu o. Chn Simulation > Delete Cache4. Chn Window > Settings/Preferences > Preferences. Click mc Timeline, chn Looping to Once > Save.5. n frame u ca vic to chuyn ng v cho play.Ta s c chuyn ng xuyn sut t frame -20 n frame 1. frame 1, mu o v qun c nh v trn c th trng t nhin hn ti lc bt u thc hin chuyn ng i b.

7. Lu trng thi khi to cho trang phc

Mc ch:

bc ny, bn s lu li v tr hin ti ca mu o v qun, xem y l v tr u tin ca chng ti thi im bt u ca chuyn ng. Lu trng thi khi to cho mu o v qun

1. Chn mu o.

2. Simulation > Save as Initial Cloth State3. Chn mu qun.

4. Simulation > Save as Initial Cloth State Tin hnh simulation cho chuyn ng i b

1. t v tr bt u v kt thc ca Time slider l 1 v 118. y l khong frame bn s tin hnh simulation.

2. Chn Simulation >Solvers >shirtExport:cpSolver1> v t frame bt u bng 1. Gi tr ny ch nh frame solver s bt u tin hnh simulation.

3. Chn Simulation > Delete Cache4. Play. Ta tin hnh simulation cho chuyn ng i b.

Sau khi cho chy simulation, chuyn ng ca qun o c ghi nhn li trong cache. Do , bn c th hy b mt s thi im trong Time slider gip cho hnh ng playback c nhanh hnNu mun tin hnh simulation li vi nhng ci t thc tnh khc th iu u tin bn phi lm l xa cache. Mc khc, vic hy b cc thi im v cho playback s s dng li cc chuyn ng ln simulation trc.III. Hot cnh v nh sng.

A. Gii thiu rendering. Rendering l bc cui cng trong x l ho 3D.Mc d ni dung tp trung ch ca rendering bt u vi shading( sng, v b mt), texturing(gn vt liu) ln i tng v lighting(chiu nh sng)ca ton b khung cnh, nhng qu trnh rendering kt thc khi cc suface(b mt), material(vt liu), light(nh sng) v motion (chuyn ng c x l tch hp vo hnh nh cui cng)1. Quan st kt qu render. Khi bn to khung cnh( gm share v texture cho i tng, nh sng cho khung cnh, v tr ca camera .v.v.) bn mun thy khung cnh ca bn nhiu ln khc nhau trc khi a ra sn phm render cui cng. Qu trnh ny c th lin quan n vic to v khi gn cc camera thm ngoi cc camera mc nh trong Maya.

Vic nhn thy khung cnh trong qu trnh trng tc pht hin v sa nhng vn v cht lng ca hnh nh, hoc gim thi gian ca qu trnh render cui cng trc khi cng b sn phm cui cng.

Khi bn ng vi kt qu ca khung cnh trong sut qu trnh kim tra render, bn c th cng b kt qu render cui cng.

Bn c th thy v kt thc render trong mt frame( mt phn ca hot hnh-nhiu frame) hoc trong ton b hot hnh.2. im quyt nh thc hin render thnh cng.

im quyt nh cho thnh cng l tm mt s cn bng gia cht lng nh cao v tc rendering(c xt nh bao nhiu frame c rende trong mt chu k thi gian.

Rendering gii quyt mt s lng ln cc tnh ton phc tp dn n my tnh phi lm vic tong mt thi gian di. Qu trnh rendering ly d liu t nhiu h thng con trong Maya v tng tc cc d liu c lin quan lm nn tn cho qu trnh p vt liu, bng, trch on phim, chiu sng.

Vic to ra hnh nh render lun lin quan vn d chn la gia cht lng hnh nh v tc d thc hin render, hoc c hai.

Hnh nh cht lng cao chim hu ht thi gian render. im quyt lm vic thun li l to ra hnh nh c cht lng va phi m thi gian thi hnh t nht c th. Trong thc t chn la gi tr c li l to ra hnh nh c cht lng c th chp nhn c trong n ca bn.B. Cc loi rendering:1. Render phn mm:

Software rendering cho hnh nh cht lng cao nht, cho php bn to ra nhng kt qu tinh vi nht.

X l tnh ton thc hin trong CPU ( tri ngc vi hardware rendering x l trn card ho. Bi v n khng b hn ch bi card ho ca my tnh, softvare rendering thng th linh hot hn. Tuy nhin c hn ch l software rendering thng chim nhiu thi gian hn.

Chnh xt l bn render nh th no l tu thuc vo software rendering no bn s dng v nhng hn ch ring ca n

Maya c 2 loi software render:

Maya software render.

Software render l render cao cp (renderer a tiu trnh). N da trn c s ca cng ngh renderer xy dng trc tip trn May ph thuc vi kin trc ho, iu c ngha cc node c trng ca software renderer c th kt ni trc tip vi cc node c trng khc troong Maya. N cung cp tnh ngh thut cao gii quyt rendering yu cu cao. Software rendering l mt render hn hp (kt hp raytracing v u th v tc ca renderer tng dng. Mc d software renderer khng chm nhng hng cht lng hnh nh mong mun phc tp th c th vt qua tc nguyn thu. Software renderer h tr nhiu thc th khc nhau thnh lp trong Maya gm cc phn t hiu ng paint, hiu ng sng m, geometry. N cng c API rt mnh cho vic thm cc hiu ng l trong qu trnh to lp. Software renderer h tr cng c IPR cho php bn to tng tc iu chnh hnh nh renderer cui cng. Quan trng nht c im t nhin ca kin trc tch hp ca Maya cho php cc kt ni phc tp( chng hn nh texture v mc c- qun l s pht ra v nhng mi quan h khc khng dc on trc c to ra cc hiu ng nhn thy c.

Mental ray for Maya.

Mental ray cung cp tt c cc c im c bn ca kha cnh photorelistis rendering v cc hm khng thy c trong software rendering. Metal ray cho php tng tc v x l mental ray rending theo l t trong giao din ngi dng. Vi s h tr ca to bng h tr hu ht cc hiu ng c sn torng Maya, th mental ray cho php rendering khung cnh c x l ngay trong Maya hoc export vo trong file nh format kiu mental (.mi). Sau khi bn chn kiu render l mental ray th mt list cc menu render c sn cc menu item cho mental ray. Cng ging nh Attribute Editor c cha mc mental ray, trong bn c th son tho cc thuc tnh s dng trong qu trnh rendering bng mental ray.2. Render phn cng

Hardware rendering s dng video card v cc driver c trong my render hnh nh ln a. Hardware rendering thng nhanh hn Software rendering, nhng thng cht lng hnh nh thp hn. Tuy nhin trong mt vi trng hp hardware rendering c th cho kt qu tt vic giao hng qua mng.

Hardware rendering khng th to ra nhiu hiu ng tinh vi (chn hn nh bng, phn x ...). to ra nhng hiu ng ny bn phi s dng software rendering.

Maya c hardware render:

Maya hardware render.

Hardware renderer trnh by cch gii quyt rendering tch hp nguyn vn,cch gii quyt ny chiu nh hng rt ln ca cht lng card ho render hnh nh. Cc thun li gm: workflow t nhin to ra hnh nh c rendering cho vic xem trc, cc phn tch c bit, v cc phn t hardware render. Bn c th render v hin th hnh nh bng Render View, Render View cho php bn so snh hnh nh trong sut qua trnh thc hin thao tc lm bng v chiu sng. Kinh nghim ca ngi dng v cht lng ca hnh nh cui cng, thy c s vt tri ca Hardware Render Buffer. Bn c th cung cp braodcast- gii quyt hnh nh trong thi gian ngn hn software rendering. Trong mt vi trng hp cht lng hnh nh tt bn giao. Hardware render dng workflow v giao din c sn thc hin lm bng, cu trc, cc phn t, lin kt chiu sng 3. Render dng vector:

Vector rendering cho php bn to ra cc rendering chun (v d nhn vt hot hnh, n ng thng, k xo trn ng thng, k xo trn ng cong, ng vin khung) trn cc format hnh nh bitmap hoc format vactor 2D. Maya c vector render:

Maya vector render.

4. Cch chn loi render:

Khi bn chn mt loi render, giao din ngi dng ca Maya s t ng cu hnh dng cho render. V d nu bn render frame hin ti, Maya dng renderer x l hnh nh v hin th n trong Render View. Hoc nu bn bitchn nt Display Render Globals Setting th ca s Render Globals Setting xut hin, chn tab Common v tab ny p ng c vic chn render.

chn render thc hin mt trong cc cch sau:

Chn Render > Render Using, cau chn render

Rendering > Rendering Editors > Render View sau chn kiu render trong drop-down list trong Render View Chn kiu render t drop-down list trong ca s Render Global Settings.

Ch : mental ray renderer v Maya Vector renderer l thm vo mc nh. Nu bn khng thy n trong listed trong Render > Render Using, th chn Window > Settings/Preferences > Plug-in Manager v chc chn phi chn Mayatomr v VectorRender plug-ins.

nh ngha renderer mc nh: Chn Window > Settings/ Preferences > Plug-in Manager.

Chn Rendering sau chn Preferred Renderer.C. Camera1. Nhn cnh thng qua camera v thc hin render qua camera. Bt c khi no d bn ang xy dng khung cnh hay ang render mt hnh nh, bn cng ang nhn qua mt camera.Tc l bn ang nhn theo mt hng vo hnh nh xuyn qua knh ca camera cho nn vng nhn ca bn b gii hn trong nhng g bn thy qua knh ca camera.

Mc d maya c 4 camera cho php bn nhn thy khung cnh trong mt panel: 1 camera phi ton cnh v 3 camera chiu thng ( t cc v tr trn u, bn hng v trc mt) ph hp vi cc cch nhn mc nh vo khung cnh. Bn nhn thng qua cc camera ny khi bn modeling, animate, share v texture cc i tng.

Thng thng bn khng s dng 4 camera mc nh ny render mt khung cnh (bn to ra 1 hoc nhiu camera thc hin vic render ny. S khc bit gia camera rendering v cc camera khc l cho php render khung cnh ca bn.2. Cc loi camera

Camera ca Maya c nhiu thun li nh camera th gi thc, diu cho bn t do sng to. V d v camera ca maya khng hn ch v kch thc v trng lng nn bn c th di chuyn camera n bt k v tr no trong khung cnh, thn ch bn trong mt i tng rt nh.

Cc camera tnh v ng: c 3 kiu camera gip cho bn to khung cnh tnh hoc ng:

S dng camera Basic cho khung cnh tnh hoc ng n gin ( chng hn nh paint ln khung cnh).

S dng camera Aim hoc Camera cho nhng khung cnh hi ng (chng hn nh camera cho php dic huyn theo g chim bay).

S dng camera Aim,Camera v Up nh ngha b mt cu cng no m camera phi hng n. Camera cy l ch chn la tt nht cho cc chuyn ng phc tp (chng hn nh camera chuyn ng quay trn quanh b bin).3. Hiu ng m n do di chuyn v su ca vng quan sta) Tp trung chiu sng v lm lu m.

X l ghi hnh la nhng g bn thy thng qua camera rt n gin: nhn vo mt nt m shutter(shutter cho php nh sng qua aperture (aperture lm cho phim tr nn sng)) ghi li nhng g bn thy.

Vic khi gn th hin ca camera c xt nh bi depth of field ( vng tp trung th hin) v c hoc khng c mt ch th b lm lu m bng thuc tnh motion.

c bit nu bn ang dng mt nh ngh thut trn khung nhn ca bn (chng hn nh cc hnh ng chuyn ng ca bn chn)th bn cn lm mt s khi gn cho camera. Bn khi gn cc setting khc nhau chng hn nh film back hoc focal length trong :

Attribute Editor ca camera c chn.

Cc la chn cho camera khi bn to ra n.b) iu chnh FTOP(APERTURE) v SHUTTER SPEED/ANGLE.

Trong cc nh ngh thut trong th gii thc vn dng kt hp fStop v shutter speed (hoc shutter angle cho cc camera chiu film) xt nh sng bao nhiu chiu len film. Tuy nhin fStop v shutter speed cng xt nh vng focus chnh xt l bao nhiu.

Chiu di ca thi gian chiu sng cho php nh sng truyn xuyn qua thu knh ca camera n film c xt nh bi shutter speed. Nu speed cao hn th thi gian trnh chiu ngn hn, nh sng chiu ln film it hn.

Lng nh sng cho php qua thu knh ca camera n film c xt nh bi vic iu chnh aperture ca camera (c bit nh l fStop). Aperture rng hn, th nh sng chiu len film nhiu hn

Shutter speed/angle xt nh s chuyn ng lu m dn: Motion blur cho ta cm gic ca chuyn ng. Motion blur c xt nh bi shutter speed. Gim shutter speed th chuyn ng kh dng li hn (c ngha l xe car chuyn ng nhanh xut hin lu m dn do chuyn ng ti gi tri shutter thp. gi tri shutter speed cao hn th xe car dng nh ng li v v th focus vo Aperture xt nh depth of field: depth of fielf l vng focus trong nh. Depth of field c xt nh bi iu chnh aperture ca camera. Ti gi tri aperture vi fStop=f/2 th chiu su ca vng b cn li v background v foreground ngoi vng focus. Ti gi tri aperture vi fStop=f/22 th su ca vng s su hn v background v foreground trong vng focus.c) Thc hin render theo kiu mental ray cho hiu ng m dn do di chuyn ra xa.

Trong render mental ray bn c th chn la gia Linear v Exact Motion Blur. Motion Blur trong mental ray lm lu m tt c mi th: bng, cu trc, nh snh, chiu bng, phn x , khc x v caustics.

Ch Linear to kt qu trong trng hp di chuyn theo mu ( s thay i v hnh khi khng c bn n). Ch Exact thm cc vector di chuyn cho tt c ng cong ca i tng di chuyn. Dng ch Exact to hiu ng lu m do chuyn ng cho cc i tng shape b bin dng. Ch Exact yu cu nhiu thi gian render v thng dch

Ch Linear ch export chuy n ng chun trnh by trn cc node transform. Khng xem xt bt c s thay i no v shape.

Motion blur c th tt, m trn c s mt phn ca i tng. Nu mt vi b mt khng di chuyn trong khung cnh hoc di chuyn chm th khng motion blur chng. vic chn motion blur no cng c th lm gim thi gian render4. Canh cc i tng trong khung nhn camera.a) iu chnh hng ca camera vin khung cc i tng trong khung cnh.

Cc cng c ca camera cho php bn thay i v tr ca camera theo nhiu cch khc nhau:

Tumble : Xoay trn camera xung quanh tm ca mt i tng c bit hoc ti im pivot ca camera.

Track : Dng trt theo chiu dc hoc chiu ngang tong khong gian.

Dolly : Di chuyn camera lai gn hoc xa view. Khi bn s dng cng c dolly , abn5 thay i phi cnh ton cc; iu c ngha cc i tng xa camera thay i trong mi quan h vi kch thc s c gi tr nh hn cc i tng gn camera. Bn c th s dng cng c dolly trong cnh ton cc hoc trong cnh orthographic. Zoom : thay i focal length(viewing angle) trn camera. Cng c Zoom khng thay i khung cnh ton ca nh cong c Dolly, tt c cc i tng trong trong frame u thay i kch thc cng mt t l. Camera khong di chuyn nhng hiu ng th khc nhau. di chuyn vo hoc ra xa view m khong thay i trong viewing angle th dng cng c Dolly.

Roll : Quay camera quanh trc nm ngang ca camera( nm bn di thu knh).

Azimuth Elevation: quay camera quanh mt im c bit trong khung nhn phi cnh. Gc gia sight line ca camera v mt ground th c gi l elevation. Gc gia sight line vi ng thng vung gc vi mt phng groung gi l azimuth ca camera.

Yaw-Pitch : cc im camera ln hoc xung(pitch- cao cng c gi l gc nghin), hoc qua tri hoc qua phi (yaw- lch cng c gi l dch chuyn) m khng di chuyn camera. Khung cnh trong khung nhn ca camera xut hin di chuyn trong hng pha trc. Nu mun di chuyn cameara ln xung hac t cnh ny qua cnh khc th dng cng c Track.

Fly: iu chnh lm bay camera trn mng hnh m khng rng buc g. Cn c fly cho php bn iu hng khung cnh ca bn nu bn dang chi game phi cnh nhn vt 3D.

iu chnh cc cng c tn th thc hin : View > Camera Tools > chn cng c thc hin iu chnh. Ring cng c Fly th ctrl+ko ti v xung tht li sau gii phng Ctrl v thao tc ko.b) iu chnh Angle of view (focal length).

Trong mi hnh nh thu c bn quyt nh mt i tng ln c no khi xut hin trong frame. V d mun c mt hnh nh gm ton b nhn vt hoc ch ci u v ci vai? C 2 cch iu chnh lm cho nhn vt ln hn trong frame l hoc di chuyn camera li gn i tng(Dolly) hoc iu chnh thy knh cho focal length di hn(Zoom).

Focal length ca thu knh l khong cch t tm thu knh n mt film. Nu lm focal length ngn hn th mt phng focal lui li gn thu knh hn.

Cc thu knh c nh ngha bi focal length ca n. Dn v ca focal length l millimeter hoc inch.

Kch thc ca cc i tng trong frame lin quan trc tip vi focal length. Nu bn tng gp i focal length( vn gi nguyn khong cch t camera n i tng) th i tng xut hin ln gp i trong frame. Kch thc ca i tng cng lin quan n khong cch t camera n i tng. Nu tng khong ch ln gp di th kch thc ca i tng gim di mt na trong frame.

Khi bn iu chnh focal length ca camera th anggle of view s m rng hoc thu hp. iu lm cho kch thc ca i tng ln hn hay nh hn trong frame. Khi focal length ln hn th angle fo view thu hp li, khi focal length nh hn th angle of view s ln hn.c) Vng hin th an ton cho mt sn phm dng cho tivi.

Bn c th hin th mt ng khung m t mt min m trong bn gi tt c cc hnh ng hoc text nu bn c k hoch hin th hnh nh render ln mng hnh tivi. Cc hnh ng v text trong ng khung s c hin th trong mi tivi.

Cc nh sn xut s dng cc tube khc nhau v t chng vo trong cc hp khc nhau cho nn c s khc nhau trong nhng g hin th; cc min hnh ng v text an ton l cc chun boardcast,cc chun ny chc chn rng cc hnh ng v text c nhn thy. Text1 an ton hcm khong 80% mng hnh v mc nhy cm i vi font cao hn nhay cm i vi cc i tng di chuyn( ngha l khong 10% l cnh ca tube, hnh ng an ton chm trong 90%).d) Mt phng ct:

Mt ct gn v mt ct xa la cc mt phng tng tng t 2 v tr t bit cch camera dc theo sight line ca camera. Ch nhng i tng nm gia 2 mt ct ny mi c render trong tm nhn ca camera. Bt c phn no ca i tng nm gn camera hn so vi mt ct gn hoc xa camera hn mt ct xa th s khng c render.

Nu mt phn ca i tng trc mt ct gn th ch mt phn ca i tng nm sau mt ct ny c render. Nu mt phn ca i tng nm sau mt ct xa th ton b i tng c render( gm c phn sau mt ct xa.

i vi nhng i tng c nm sau mt ct xa th s b ct b. Nu i tng c thuc tnh transparency( trong sut) ln hn 0 th mt phn nm sau mt phng xa s b ct xn.

Ch : Trong Software rendering, nu hin tng khc x xy ra, mt i tng nm ct ngang mt phng xa th s khng b ct xn m bo gi tr transparency.5. To v s dng camera.a) To v s dng camera: to 1 camera mi: Create>Cameras>Camera Type chn kiu camera mun to.

Ch : Nu bn khi to cc chn la cho cc kiu camara m bn mun to th bn ch cn chn kiu camera khng cn khi to cc chn la ca n vo lc ny v n khi to mc nh.b) iu chnh cc thuc tnh ca camera.

Cc thuc tnh ca camera m t cc c im ring bit ca camera bao gm cc thuc tnh: angle of view, focal length, depth of field.

iu chnh cc thuc tnh ca camera:

Chn camera , click View> Select Camera th ca s Attribute Editor xut hin. Nu n khng xut hin th click View > Camera attributes.

Gn gi tr cho thuc tnh. iu chnh cc thuc tnh ca camera.c) To ra camera c kh nng render.

Mc nh khung cnh ca bn ch c 1 camera c kh nng render ( camera phi cnh mc nh), camera ny c kh nng render tt c cc i tng nm trong khung cnh ca bn.

Nu bn mun thm mt camera khc vo khung cnh ca bn v mun lm cho n c kh nng render ( hoc bn mun lm cho bt c camera ho mc nh c kh nng rander), th bn phi khi to cho camera ny c kh nng render. Bn c th c nhiu camera c kh nng render .

to camera c kh nng render :

Chn phn Output Settings trong ca s Attribute Editor ca camera chn Renderable ( nu bn khong mun render th tt Renderable trong phn Output Settings trong ca s Attribute Editor).d) Bt/ tc ng vin ca khung nhn. Bn c th bt/tc ng vin ca khung nhn bn c th nh vng gii hn an ton cho cc loi thng tin (vng an ton cho hnh ng, text, ng gii hn render).

Bn c th hin thi nhiu ng vin khung nhn cng mt lc bng cch m Attribute Editor v chn cc chn la trong phn Display Options. Bt tc ng gii hn an ton cho hnh ng: click View > Camera Settings > Safe Action Bt /tc ng gii hn an ton cho title(text): Click View > Camera Settings > Safe Title. hin th ng vin Resolution Gate: chn View > Camera Settings > Resolution Gate.

e) iu chnh depth of field: Bn c th xem khang cch tnh ton c t camera n i tng v p dng gi tr vo Focus Distance cho camera kin trc nn cc hiu ng ca Depth of Field trong Attibute Editor ca camera. to ra hnh nh c Depth of field rng hn ta dng cc gi tri fStop cao hn( chng hn nh f16, f22, f32. lm cho Depth of field thu hp li hn dng cc gi tri fStop thp hn nh f2.8, f4, f5.6. Tu thuc vo gi tr ca fStop v Focus Region Scale m cc phn ca i tng c th c focus hay khng c focus. chc chn tm ca mt i tng trong vng focus ca Depth of Field.

Chn i tng mun nhn. Dng gi tri Distance to Camera nh gi tr ca thuc tnh Focus Distance trong phn Depth of Field ca camera hin hnh.

Nu bn chn nhiu i tng, Maya c th dng tm ca khi hnh hp bao quanh cc i tng ny tnh ton khong cch n camera.

f) Nhn thng qua mt camera:

Nu bn c hn mt camera bn mun chuyn vic nhn t camera ny sang camera khc th bn lm 1 trong cc cch sau:

Click Panel > Look Through Selected.

Click Panel sau chn tn ca camera mun chuyn t submenu Perspestive or Orthographic

g) Vin khung khung cnh: Di chuyn camere ra t v tr ny n v tr khc: Bn c th hin th camera nh mt i tng v s dng cc iu khin chun di chuyn n. l ging nh nm gi camera( camera ny khng phi l camera m bn ang nhn qua n ) v di chuyn n t v tr ny n v tr khc. Vic di chuyn camera la cch hu dng nu bn mun xem cc mt phng ct xn, qu o quan st ca camera hoc vng nhn thy (hnh chp ct gii hn bi 2 mt ct) cc. di chuyn camera chn camera v dng cng c Move di chuyn camera. Chnh hng quan st cho camera dng cc cng c ca camera nh Dolly, Track . nhn mt i tng qua camera: View > Look At Selection th came ra s di chuyn trnh by cc i tng ti trung tm ca khung nhn. nhn v lm y khung nhn bng nhng i tng bn chn: View > Frame Selection ( hoc nhn phm f) th camera s di chuyn lm khung nhn bng cc i tng chn. nhn v lm y khung nhn bng tt c cc i tng trong khung cnh: chn View > Frame All th came ra s di chuyn lm y khung nhn ca camera bng tt c cc i tng trong mng hnh ( k c cc ngun sng v camera nu cc biu tng ca chng hin th trong khung nhn). nhn v in y khung nhn bng mt min trong khung cnh: Ctrl+Alt+r trn mt vng mun hin th th camera s di chuyn in y khung nhn ca camera bng min c chn. Bn c th ghi li s di chuyn ca camera vo trong Scrip Editor( MEL Journal) cho php bn undo hoc redo li s di chuyn ca camera hoc copy li s di chuyn dng li trong cc khung cnh hoc camera khc: View > Camera Setting > Fournal.

D. Chiu sng (lighting):1. Cc khi nim trong chiu sng:a) Chiu sng v chiu bng: Trong th gii thc, khi nh sng chiu ln mt b mt. Phn b mt gp nh sng s c chiu sng, phn b mt quay lng li vi ngun sng s b ti. Nu mt i tng c t gia ngun sng v mt i tng th hai th i tng th nht s bng ln i tng th 2.

b) Hp th, phn x, khc x nh sng. Mu ca cc i tng bn thy trong th gii thc l kt qu ca qu trnh i tng tng tc vi nh sng. Khi sng nh sng gp i tng th i tng c th khc x, phn x, hoc hp th nh sng. Tt c cc i tng u c mt mc phn x v hp th nh sng. Ch : Trong th gii thc nh sng c th c truyn ra bi mt i tng. iu c ngha l nh sng truyn qua mt i tng m khng nh hng g (v v x-ray). Tuy nhin cc kiu ngun sng khng thy c trong Maya bi v chng khng gy ra hiu ng thy c. Hp th nh sng: nh sng dng li ti mt i tng v khng gy khc x, phn x. Cc i tng xut hin bng ti hoc m c. Phn x trn b mt trn. nh sng pht ra t b mt ca vt liu vi mt gc bng gc m sng nh sng ti. Phn x chia ra lm 3 loi: Phn x phn tn (Diffuse reflection): b mt phn tn phn x nh sng vi nhiu gc khc nhau. Phn x phn tn cho ra nhiu mu hn so vi cc phn x c trng khc bi v hu ht cc i tng l c v phn x nh sng phn tn. Phn x ho quang to ra ( Glossy reflection): cc b mt ho quang l cc b mt phn x vi nhiu b mt nh ghp nhau to thnh cc gc. Cc b mt nh phn x nh sng khng ch phn tn m cn phn ( ti cc gc nh sng gn nh l truyn phn x) lm cho b mt xut hin ho quang. Phn x ton phn: b m phn x ton phn phn x nh sng mt gc bng vi gc nh sng ti. Phn x ton phn lm cho cc i tng nh to ho quang hoc phn chiu nh gng.

Khc x: nh sng truyn qua i tng v b lch mt gc.

Khc x phn tn: to nh sng trong nhiu go khc nhau.

Khc x pht ho quang: cc mt phng to ho quang l tp hp cc mt phng nh ghp li vi nhau mt gc to ra mt phng. Cc mt phng nh ny khng ch khc x nh sng phn tn m cn pht ho quang ( ti cc gc gn nh l khc x ton phn) lm cho b mt xut hin ho quang).

Khc xa ton phn: b mt khc x nh sng cng mt gc vi gc ca nh sng ti b mt.

c) Chiu sng trc tip v chiu sng khng trc tip: Chiu sng gin tip (chiu sng ton cc): nh snh khng trc tip l nh sng phn x. Chiu sng ton cc tng xng vi truyn nh sng khng trc tip trong thc t. Vi chiu sng ton cc, s gp phn ca nh sng trong phm vi xung quanh t cc b mt khc trong khung cnh c s dng tnh ton s thm vo ca cc ngun sng v gi tr mu ti mt im trn i tng m i tng khng trc tip c chiu sng ( ngha l nhng im khng nhn c nh sng trc tip t ngun sng). Chiu sng ton cc khi nh sng b phn x hoc truyn qua i tng c ( trong sut hoc bn trong sut) n vng gii hn ca i tng hoc pht ra t i tng khc. V d. nh sng truyn b ti y ca cnh ca c th lm cho nh sng trn vo phng. Bc tng trng phn x nh sng t ngun sng n cc i tng khc trng phng. Nc c th truyn nh sng t mt nc ln sn nh. Chiu sng trc tip( cc ngun sng). Chiu sng trc tip ch khi nh sng c pht ra trc tip t ngun sng. nh sng trc tip c pht ra trc tip t ngun sng v truyn theo ng thng n im c chiu sng. V d: Ngun sng spot chiu sng vo din vin trn sn din. nh sng mt tri chiu sng trc tip vo bi tm nng. Vi vic chiu sng trc tip ch mi khi thm vo mt ngun sng mi th c tnh ton trn ton b cc nh sng b sung n mt im c chiu sng.2. Cc loi ngun sng trc tip:

a) Cc ngun sng trc tip: Maya c mt s cc ngun sng cho php bn cu trc nhiu hiu ng nh sng rng ri. Maya c mt s cc ngun sng cho php bn cu trc nhiu hiu ng nh sng rng ri. Nu khng c ngun sng no trn khung cnh th khung cnh l mu en khi render bi v khng c nh sng chiu ln i tng. Bng cch iu khin cng , mu sc, hng th nh sng tr thnh mt yu t chnh to khung cnh Maya. Vi Maya bn phi iu khin nhiu trn placemet,intensity v cc thuc tnh khc ca ngun sng hn l lm vic vi nh sng thc. Chiu bng, to sng, hightlight v sng m thm vo to hiu ng nh sng nh th no trn khung cnh.

b) Thc hin render bng mental ray: Mc d bn c th thc hin render ngun sng area bng mental ray, nhng n ch c th s dng nh ngun sng trc tip. Nu bn mun render ngun sng area bng mental ray to s chiu sng khng trc tip th bn phi dng mental ray cho area light. Mc d bn c th thc hin render ngun sng area bng mental ray, nhng n ch c th s dng nh ngun sng trc tip. Nu bn mun render ngun sng area bng mental ray to s chiu sng khng trc tip th bn phi dng mental ray cho area light. Bn to mental ray cho area light bng cch gp ngun sng point light v ngun sng spot light thnh mt. Mental ray cho erae light lm vic bng cch chiu tia sng t mt im c bit thnh.c) Vic chiu sng mc nh trong Maya: Mc nh trong Maya khng c ngun sng. Tuy nhin vic chiu sng mc nh gip cho thy c cc i tng hin th dng cc khi trong khung nhn khung cnh (nhn 5). Nu bn tc chiu sng mc nh v khng c ngun sng trong khung cnh th khung cnh s xut hin ti. Mc nh trong Maya khng c ngun sng. Tuy nhin vic chiu sng mc nh gip cho thy c cc i tng hin th dng cc khi trong khung nhn khung cnh (nhn 5). Nu bn tc chiu sng mc nh v khng c ngun sng trong khung cnh th khung cnh s xut hin ti. Bc/tc cc ngun sng nu lm mun thy v render mt i tng to sng. Ngun sng mc nh ti thi im render:

Nu bn mun render mt khung cnh m khng c mt ngun sng no th Maya to ra mt ngun sng durectional trong sut qu trnh render cho nn bn c th thy c cc i tng. Nu khng c ngun sng ny th cc i tng ca bn khng c chiu sng v kt qu render ca bn l mt mu en. Ngun sng mc nh c to ra bi camera render. Ton b khung cnh c chiu sng v khng c vn d camera i din vi ngun sng. Vng b mt i din trc tip camera s sng cn phn n sau camera s ti. iu ny lm cho cc mt trng ging nh tht. Sau khi render hon tt, Maya b ngun sng mc nh trong khung cnh. Ch : Ngun sng mc nh IPR c thm vo khung cnh trong qu trnh s l render bng nhiu cch chn hn nh ngun sng mc nh ti thi im render. Ngun sng mc dnh IPR s b b i ngay sau khi x l IPR kt thc ( v d khi bn click nt IPR stop). Ngun sng mc nh IPR khng c lu cng vi khung cnh, ngn cn bn thc hin thm ngun sng vo khung cnh bn lu.d) Gim cng sng theo khong cch.

Trong thc t sng c ngun sng mnh nht ti ngun sng v gim dn khi xa ngun sng. Trong Maya th gim cng sng xy ra nu thuc tnh decay c chn. Tuy nhin mu ca ngun sng vn gi nguyn khng b thay i theo khong cch.

Trong thc t sng c ngun sng mnh nht ti ngun sng v gim dn khi xa ngun sng. Trong Maya th gim cng sng xy ra nu thuc tnh decay c chn. Tuy nhin mu ca ngun sng vn gi nguyn khng b thay i theo khong cch.

Trong Maya bn c th chn gi tr ca gim cng sng bng cch khi to cc thuc tnh ca Decay Rate. Vic khi gn trc gim cng sng th thng khng to ra tt c cc hiu ng nh sng. Tuy nhin trong mt vi trng hp bn c th to ra mt kiu gim sng c trng ring cho mnh.

e) Lin kt cc ngun sng.

Khi bn to ra mt ngun sng, th ngun sng mi s chiu mc nh ln tt c cc b mt trong khung cnh. Tng t khi bn to ra mt b mt th tt c cc ngun sng s chiu ln n.

Khi bn to ra mt ngun sng, th ngun sng mi s chiu mc nh ln tt c cc b mt trong khung cnh. Tng t khi bn to ra mt b mt th tt c cc ngun sng s chiu ln n.

Bn c th lin kt cc ngun sng vi cc b mt (hoc mt nhm cc b mt) hoc mt i tng ( hoc mt nhm cc i tng) nhn chiu sng ca mt ngun sng c bit.

Lin kt vi ngun sng gip bn render thun tin hn v nhanh hn. Bn c th to ra cc khi to ban u xho ngun sng iu khin mi quan h gia cc ngun sng v cc i trng trong mt khung cnh phc tp.

f) Hiu ng nh sng sng rc( glow), ho quang (halos) v chp chn m la (lens flares).

Bt c ngun sng no thy c trong camera u c kh nng gy ra mt hiu ng quang hc c bit. Bn c th s dng kh nng ca Optical FX to ra cc hin tng pht ho quang, to sng, bp bng ca nh la tr n bt k ngun sng no chiu trc tip vo camera.

Bt c ngun sng no thy c trong camera u c kh nng gy ra mt hiu ng quang hc c bit. Bn c th s dng kh nng ca Optical FX to ra cc hin tng pht ho quang, to sng, bp bng ca nh la tr n bt k ngun sng no chiu trc tip vo camera.

Ch bn cng c th iu khin vic to sng nh th no t mt b mt nh hng ln to sng ca mt b mt khc hoc to s th hin m cho mt ngun sng c bit.

Thc hin to sng nh th no trong animation.

c bit trong qu trnh animation, ngun sng s b hp th bi cc i tng di ng. Trn thc t, s di chuyn ca i tng t t lm cho hiu ng quang hc to sng gim dn. Tuy nhin trn ho my tnh hin tng to sng s t ngt bin mt(iu ny lm cho mt t nhin i vi mt ngi).

Trong Maya, khi bn thn s to sng cho mt ngun sng, th cc i tng geometry s t ng c to ra tnh ton phn trm nhn thy ca nh sng lm cho cm gic mt thc do to sng to ra gim i .

i vi ngun sng spot th cc vng trng c to ra.

i vi ngun sng point to ra hnh cu i vi ngun sng area th cc hnh ch nht c to ra.3. Chiu sng ton cc v hin tng caustisc

a) Chiu sng ton cc: Chiu sng ton cc: l mt k thut c s dng thc hin chiu sng khng trc tip, cc hin tng t nhin m nh sng bao quanh bt c th g trn ng truyn ca n cho n khi n hon ton c hp th.

Chiu sng ton cc cho php bn thit k trong nh thc ( b sung cc nh hin tng chiu sng trong th gii thc, l mt cch tt thc hin:

Thy c cu trc v cc project thit k trong lnh vc cng nghip. Cc n yu cu tnh chnh xt v chiu sng vt l.

Cc profect gii tr yu cu c th bn c nhng khng yu cu tnh chiu sng vt l chnh xt Mental ray to chiu sng ton cc bng cch theo ng i ca phonton v ghi li cc im bin ca n trong p phonton.

b) Caustisc: l hiu ng nh sng c bit c to ra bi phn xa, kuc xa hoc tn sc nh sng. Caustisc l mt dng ca chiu sng ton cc nhng c x l bi metel ray cho ta d iu khin chng

c) Ph mu: Ph mu l hiu ng chiu sng ton cc, nh sng phn x ph cc mu phn x ln b mt gn .

Ph mu l hiu ng chiu sng ton cc, nh sng phn x ph cc mu phn x ln b mt gn .

Mu pht sng ca i tng c phn x trong khi mt phn mu ca n b hp th. nh sng b phn x c th ph mu pht ra ln i tng gn n.

d) Participating media: Participating media l hin tng chiu sng khng trc tip, nh sng tng tc vi mt phn nh khng gian b mt hn l ton b khng gian hn b mt. Trong Maya cc phonton tng tc vi hiu ng nh sng trong khng gian (cc hiu ng ny tham gia vo qu trnh truyn nh sng bng cch hp th mt t nh sng).

Participating media l hin tng chiu sng khng trc tip, nh sng tng tc vi mt phn nh khng gian b mt hn l ton b khng gian hn b mt. Trong Maya cc phonton tng tc vi hiu ng nh sng trong khng gian (cc hiu ng ny tham gia vo qu trnh truyn nh sng bng cch hp th mt t nh sng). V d Participating media l cc tia sng trong vng m ca lung sng t n trc ca xe car.

Participating media lm vic ging nh cch global illumination lm vic trn b mt, ngoi tr volume shaders v volume photon shaders c yu cuE. nh bng b mt1. Cc khi nim:

a)nh bng ca b mt

Trong thc t bt k mt i tng c to ra l 1 trong 2 yu t chnh xt nh s xut hin ca cc b mt (khng phi ngun sng). y l bi v khi nh sng gp i tng th mt t nh sng c hp thu mt t nh sng phn x lm cho cc i tng ln hn, sng hn.

Trong May s xut hin ca i tng c xt nh bi shaded ca i tng nh th no. Vic lm bng mt b mt l s kt hp vt liu ca cc i tng v kt cu c p ln i tng .

Trong Maya matarial( cn c gi l shades) nh ngha vt liu ca i tng. Mt v thuc tnh c bn ca vt liu l mu sc tong sut v chiu sng.

Cc nh sn xut cn c vo mu sc, d trong sut v chiu sng xt nh s xut hin ca b mt ca i tng ( gm nhiu th phc tp nh mu sc, trong sut, chiu sng, g gh ca b mt, phn x, hoc vng kh quyn bao quanh) th c nh ngha bi cu trc(texture).

b)Cu trc b mt:

Texture l mt kiu chi tit v b mt ( k c thy c v cm gic s vo c. Trong Maya, bn c th to ra chi tit b mt vi texture kt hp vi vt liu ca i tng nh l p vt liu.

Cc nh sn xut cn c vo mu sc, trong sut, chiu sng xt nh s xut hin ca b mt ca i tng gm:

g gh ca b mt.

B mt chiu hoc nhn nh sng phn x Cc hin tng t nhin

Bn cng c th chiu sng hac pha mu vo texture m su ny bn s p vo khung cnh ca bn.

Mu: bn c th lm vic vi mu trong Maya theo nhiu cch khc nhau sau y l mt s cch thng dng:

Thay i mu ban u ca i tng bng cch iu chnh thuc tnh mu ca vt liu p ln i tng.

p texture nh l p mu vo thuctnh mu ca vt liu.

Dng Ramp Shader iu khin nhiu cch thay i mu vi nh sng v gc nhn. Bn c th vn dng nhiu kiu vt liu l v bng phc tp.

M rng, thc hin hoc vn dng mu vo texture c p bng cch s dng cc thun li ring ca mu sc nh iu chnh sng, pha mu, chuyn mu HSV sang mu RGB.

trong sut: bn c th lm vic vi trong sut ca mt i tng bng cc cch sau y:

Thay i mc trong sut ca mt i tng bng cch thay i thuc tnh transparency ca vt liu c p ln i tng.

p texture nh p transparency ln thuc tnh transparency ca vt liu thit k ra vng trong sut, bn trong sut, hp th nh sng trn i tng.

To sng ( specular hightlight): bn c th lm vic vi chiu sng ca cc i tng trong khung cnh theo nhiu cch sau y:

Thay i sng v kch thc ca specular hightlight ca mt i tng bng cch iu chnh thuc tnh Specular Shading ca vt liu p ln i tng.

p texture nh p specular ln thuc tnh Specular Color ca vt liu thit k vng to sng ca i tng v mu ca hightlight.

Specular hightlight l g:

Mt vi b mt th sng hn cc b mt khc (v d mt co c t c b mt sng hn mt l cy kh). Tu thuc vo b mt c chiu sng nh th no m s phn x nh sng theo nhiu cch khc nhau.

Cc i tng to sng th phn x nh sng trc tip. Specular hightlight th hin mt ni trn i tng phn x nh sng vi mt gc c nh ( phn x trn mt i tng dc theo cc hng no v nh sng bao trm ln tt c cc i tng xung quanh )

Specular hightlight tu thuc trc tip vo khung nhn(camera) khng phi v tr ca ngun sng.

Kch thc ca speculer hightlight trn mt b mt lm cho b mt trong nh bng phng v to sng.

Bn c th iu khin mu ca hightlight trn cc b mt.

Bn c th iu khin mc phn x cng nh cc thuc tnh khc ging nh mu khc x.2. Shading networks:a) Shading network

Mt shading network l tp hp cc node rendeing ni vi nhau, cc node ny tu thuc vo mu v texture p ln vt liu ca b mt. Shading network thng bao gm mt s cc node render c ni vi nhau v kt hp vo mt node shading group.

iu linh ng ca shading network vo thi im bn xy dng th tu thuc vo s kt hp ca cc thuc tnh ca node ny vi cc thuc tnh ca node khc v iu chnh thuc tnh ca node m t cc b mt nh th no v n nn dt v tr no.

Thm mt shading network:

Mc nh khi bn thm mt file nhiu ln vo Maya th geometry v shading network s t nhn ln. Cc shading network khng cn thit v geometry khng cn thit s lm tng dung lng( b nh) ca khung cnh v thi gian load v khungcnh ca bn lm vic nng n hn. Bn c th ngn cn vic nhn i ca shading network khi bn import khung cnh, hoc bn c th xo b network sau khi c nhn ln trong khung cnh ca bn.

trnh shading network khng cn thit trong khi bn import mt khung cnh th bn chn Remove Duplicate Shading Network.

xo shading network khng cn thit th vo Hypershade chn Edit > Delete Duplicate Shading Networks. Shading group node:

Shading network c thit k nh mt mng ca dng d liu( mng ca dng d liu l ni d liu dtream t bn tri ca network cho ra kt qu shaded cui cng, kt qu cui cng c sp xp t cc node bn phi. Hu ht cc node bn phi l shading Group ca mt mng c bit.

Shading Group l tp hp ca vt liu,texture, nh sng m t cc thuc tnh cn thit yu cu thc hin render hoc shade mt hnh nh.

Tt c cc node bn tri ca shading group b sung cho hnh nh nhn thy cui cng ca b mt. Vic iu chnh cc thuc tnh ca node hoc cc kt ni gy ra tng tc li pha bn phi ca node c th thy c trong hnh nh render cui cng.

b)Cc node render:

Cc node l cc b phn ring r bn thc hin kt ni xy dng thnh cc khi to dng cung cp tt c cc hiu ng render. Ging nh cc node khc trong maya bn c th to ra hoc p cc note render vo cc tham s ca node khc.

Cc node texture, placement, material i km vi cc thuc tnh kt ni vo ra nh ngha cc c im ca hnh nh render ci cng ( t b mt n chiu sng, bng).

Bn c th to cc kt ni cc hiu ng m bn mun. Bn c th chia s cc node to cc mi quan h nhn thy c v to ra nhiu hiu ng ender hn. V d hai i tng c th cng chia s mt texture nn hai i tng ny xut hin ging nhau nhng t tn b nh hn v yu cu x l t hn.

Bn c th lm vic vi cc node render v shading network trong Hypershade.

c) Cc thuc tnh ca node render: Mt thuc tnh ca node render m t mt c im ca node. Cho nn khi bn iu chnh mt thuc tnh ca node th bn s iu chnh c im m n m t. V d nu bn thay i thuc tnh mu t sang xanh hoc bn c th thay i i tng t m c sang tong sut bng cch diu chnh thuc th transparency.

Mc d bn c th tng tc iu chnh mt vi thuc tnh, bn c th thay i hoc ghi mt gi tr s chnh xt bng cch s dng Attridute Editor hoc iu chnh hoc hin th cc thuc tnh node trong Attribute Spreadsheet hc Channel Box.

d) Kt ni cc node render: Cc kt ni cc thuc tnh c th hin bng ng thng c t mu trong Hyperrshade. Cc ng thng kt ni cc node m t kiu d liu no c truyn qua kt ni. Tu thuc vo kiu kt ni v cng dng ca mi ni m thng tin truyn qua s khc nhau. Cc gi tr l mu, khong cch v tr, gc, ID ca i tng.

Cc thng tin c th truyn qua l mt gi tr n ( v d OutAlpha l mt gi tr n) hoc mt nhm ( v d gi tr RGB hoc gi tri XYZ). Cc kt ni nhm th hin bng ng ni xanh l cy cc kt ni khc c mu mc nh.

Bn c th thit lp mu khc v ngha ca n bn thay i mu mc nh ca ng kt ni.

Mi node c mt thuc tnh mc nh v mt tp cc thuc tnh dng kt ni. Tuy nhin Connection Editor l cng c tt nht lm vic vi shading network v cho vic to cc kt ni khng phi l mc nh.

Connection Editor th hin thng tin ca mng cc node dng t pha ny n pha kia cho nen bn c th xem 2 node c kt ni trong mang cc node. Bn c th nhanh chng di chuyn d dng t node ny n node khc v thy c cc u vo v u ra ca node. iu gip cho thun tin trong cc kt ni ( c ngha l bn c th to ra cc kt nitrc tip trong mng cc node.3. Cc loi vt liu:

a) B mt, thay i li lm, khng gian ca vt liu. Mc d cc b mt trong Maya c phn hi vi nh sng ging nh trong th gii thc, nhng c s khc bit trong cch nh sng tng tc vi b mt trong phn mm ho my tnh. Cc node material l mt loi node render ( khi bn p node vt liu ln mt i tng cho php bn nh ngha i tng xut hin nh th no).

Trong Maya, cac node material nh ngha b mt tng tc vi nh sng nh th no. Maya cha nhiu kiu node material khc nhau gip bn to cht lng v c im ca b mt tc ng vi nh sng ging nh trong thc t.

Bn c th khi gn cc thuc tnh ca vt liu nh mu sc, trong sut, tn sc nh sng, phn x v thng tin chi tit b mt ca cc thnh phn trong khung cnh to ra hnh nh thc hn.

Khi bn to ra mt i tng th Maya mc nh gn vt liu Lambert cho i tng.

Surface ca vt liu: b mt ca vt liu th hin kiu b mt m trn bn c th p texture. Cc thuc tnh nh chiu sng, b mt( m), phn x, pht quang V d nu texture yu cu b mt chiu sng th s dng vt liu Phong hn l Lambert.

Displacement ca vt liu: cho php bn s dng hnh nh nh ngha s li lm ca mt b mt i tng.

Volumetric ca vt liu: Trong thc t khi bn to hnh nh ca mt i tng th i tng nm trong atmosphere(khng kh v c bao quanh bi cc i tng khc (background). Volumetric ca vt liu m t s xut hin hin tng vt l k l (hin tng ny xy ra trong khng gian v d nh khi., sng m, v cc hin tng c bit khc. Bn c th thay i vulumetric ca vt liu v cung cp cc hiu ng nh hin tng m ca lung sng phn x hoc khc x qua gng.

b) Dng nhiu shade Khi bn mun s dng nhiu vt liu trn mt i tng th bn c th dng nhiu shader. Cc layered shader cho php bn to ra s xut hin ca nhiu vt liu trn mt b mt bng cch ni nhiu node material li vi nhau. Layered shaders thc hin render chm hn cc vt liu khc cho nn cn cn nhc vic s dng layeder texture thay cho layeder shader to cng kt qu nh mong mun.

Cc node layeder texture v layeder shader: Layeder Shader c thuc tnh compositing flag quyt nh kiu layeder meterial hay layeder texture. Bn c th s dng diu ny t nhiu texture cng vi node Layeder Shader. Tuy nhin ngh s dng Layeder Texture hn bi v bn bn c th iu chnh nhiu chn la hn. Nu bn chn c chn texture th bnphi thm ton b mng vo trong material.

c) To shader hai pha ca mt b mt: Double-sided shading cho php bn to ra mt b mt vi pha bn ny mt loi vt liu, pha bn kia mt vt liu khc. y ch l cch bn c th c th p nhiu vt liu vo mt mt NURBS.4. Cc loi Texture:

a) Texture kiu 2D v 3D: Cc node texture l cc kiu node render cho php bn nh ngha b mt ca i tng xut hin nh th no khi render.

Cc node texture gn vo node Group Shading (nod eGroup Shading th hin thc hin render ln shade ca b mt nh th no.

Node texture l c to ra bi Maya hoc cc hnh nh import vo Maya. Texture cho php bn p vo nhu thuc tnh khc nhau ca material nh color, bump( li lm) v cc hiu ng c bit khc.

Texture kiu 2D: 2D texture dn bao quanh mt i tng hoc gn ln mt b mt bng phng.

Texture kiu 3D: 3D texture bao b ton b i tng k bn trong ca i tng ging nh ng vn bn trong hoc g. Vi 3D texture cc i tng xut hin nh b ghp tng lt vt liu.

Texture kiu environment: Environment texture thng c s dng nh background cho cc i tng trong khung cnh hoc p hin tng phn x.

Texture kiu layeder: C 2 cch sp lp texture( dng cch gn c hiu compositing flag trong layeder shader hoc vi Layeder Texture Node.Mc d th t lm vic trong Layer Texture Node ging nh lm vic trong Layeder Shader nhng khuyn khch dng Layeder Texture Node bi v bn c th khi to nhiu ch trn ln vi nhau.

b) Texture kiu Procedural: Procedural texture c to ra bi Maya. Trong thc t cc kiu textture 2D, 3D l cc procedural texture. Procedural texture l cc pht ho 2D, 3D bng cc hm ton hc khng ph thuc vo phn gii( thay i kch thc). Bn c th iu chnh cc thuc tnh thay i cc c im ca procedural texture thy xut hin khc i. 2D procedural texture x l ging nh 2D file testure thay v gn thm h to UV cho geometry. 3D procedural texture b qua h to UV.

c) Texture kiu file: File texture l cc bitmap c scan t cc nh chp bng my quay k thut s hoc cc gi c v 2D hoc 3D bn em vo Maya nh mt bitmap. File texture lc tt hn procedural texture v c th cho ra hnh nh cht lng hn. Ch bn c th render ton b mt nhnh ca shading nerwork dng chiu sng, chiu bng, to bng v texture nh p file texture cho cc l do sau:

Gim thi gian render cho mt network phc tp hoc cc c im chiu sng ton cc trong mental ray phc tp.

cha cc hiu ng kh to lp d l dng nhiu cch khc nhau.

Cc hnh nh HDR khi p cc texture kiu file: Mental ray h tr cc hnh nh High-Dinamic Range (HDR) khi thc hin texture kiu file.

Xem xt cho vic to file texture:

Cc file texture ng: S dng mt chui cc file hnh nh to ra mt file texture ng. Cc ui m rng phi c ngn cch bi du chn vi basename ca file.

Cc file textture trong hardware rendering: Thng thng khi rendering vi file texture th cn xem xt c khong bao nhiu khng gian b chm trong khng gian mng hnh. Cc texture ln hn s chm nhiu b nh v thi gian thc hin bi v hardware rendering phi s dng nhiu thi gian lm gim kch thc ca chng. C gng gi cho texture nh n mc c th khi thc hin render iu ny lm gim b nh v thi gian rendering v v th cho kt qu cht lng tt hn. Cc hnh nh c kh nng dng li:

Ging nh cc texture khc, bn c th p mt file texture ln mt thuc tnh no ca vt liu. Bn c th p file texture nh mt hnh nh sau ny c kh nng lp li(khi cc ng vin hnh nh texture c thit lp)

Procedural texture mc nh l c kh nng gieo trng ( lp li). Nhng nu bn mun lp li mt file texture th bn phi chc chn l cc cnh vin phi nguyn vn khng chp ni. chc chn c im ny ca cc cnh vin bn dng mt gi son tho hnh nh lm cho cn bng li hnh nh sau xem xt vng sng ti trong file c kh nng lp li c cn bng.

Cc hnh nh c kh nng dng li c th c chia thnh cc mnh nh hn cc hnh nh c kh nng dng li ny load nhanh hn, d dng hn khi render (lu li cc thay i ti thi im render).

Cc hnh nh vung v khng vung: Bn mun texture ca bn phi va vi mu ca bn mc d texture l c paint. Bn c th o khong cch t b mt n texture c p. Tuy nhin v Maya thun tin hn nu n c th thc hin t l texture khng vung thnh texture vung bng cch s dng hnh nh vung th c khuyn khch hn. Nu i tng m bn ang p texture khng vung th s t trxture ca bn mu en.

d) Texture kiu file Photoshop: Cc file photoshop( phin bn 6.0+) c h tr, thun tin cho vic thc hin mt chui thao tc paint n gin theo mt trong cc cch sau:

Bn c th dng mt file photoshop c sn trong Maya bt c ni no bn mun p texture.

Bn c th chuyn file PSD vi mt tp cc lauer thnh Layered Texture trong Maya gip cho bn thy v lm vic vi cc tp layer ring bit.

Bn c th to file layered PSD t trong Maya vi th t nhiu knh (color,bump, specular) ring r trn mt i tng trong Adobe Photoshop.

Bn c th dng cng c paint 3D trong Maya pht tho mt i tng tng tc nh ng vin bo m trnhnh nh photoshop c paint(ng vin bo o ny hu dng khi cc h to UV khng xut hin hoc c sn.

Bt c lc no bn cng c th thay i file PSD trong photoshop khi update lai hnh nh trong Maya thy s thay i nagy lp tc.

e) B lc texture:

B lc texture l mt k thut anti-aliasing oc s dng d nh ngh li file texture, gim co git mng hnh, to cc hiu ng c bit. Cc thuc tnh Fliter ca file texture th lm t l li kch thc ca fliter v cho php bn nh ngha mt s lng ln cc vch lm m trong trxture c p.

Nu cc hnh nh p texture qu sc nt th n c th th hin cc hiu ng trong hnh nh render cui cng. mc nh Fliter c khi gn gi tr l 1.0 ngn cn cc hiu ng ca aliasing.

Cc nh hng ca Filter c lin quan trc tip dn khng gian mt. Khi mt i tng di chuyn xa mt th texture s lu m dn.5. p texture v nh v texture.

a) p texture: Maya c mt nhiu loi texture m bn c th p vo mt i tng.

p texture vo mt i tng th bn p (ni) texture vo cc thuc tnh material ca i tng. Cc thuc tnh m texture ni vo xt nh texture c s dng nh th no v vy nh hng n kt qu cui cng nh th no.

V d nu bn ni texture 2D bback and white Checker vo thuc tnh color ca vt liu th bn thc hin p mu (checkered parttern xt nh phn no ca i tng th mu trng phn no ca i tng th mu en hoc mu khc nu iu chnh thuc tnh color ca texture). Nu bn ni texture black and white Checker vi thuc tnh transparency th bn thc hin p vo trong sut ( checkered pattern xt nh phn no ca i tng th trong sut phn no ca i tng th c).

Cc kiu p vt liu:

p mu: bng cch p texture ln thuc tnh color ca i tng th bn to ra cch p mu m t mu ca i tng.

p trong sut: bng cch p texture vo thuc tnh transparency ca vt liu ca i tng th bn to ra p mu cho php phn ny ca i tng th trong sut, phn th bn trong sut,phn th m c.

p vo s tn sc nh sng: nu bn p texture vo thuc tnh specularity ca vt liu ca i tng th bn p texture vo tn sc nh sng cho php bn m t s chiu sng trn i tng nh th no.

p s phn x nh sng: bng cch vt liu vo thuc tnh reflection ca vt liu ca i tng th bn to ra p phn x nh sng m t i tng phn x nh sng xung quanh n nh th no.

p li lm: bng cch p texture ln thuc tnh bump ca vt liu i tng th bn d thc hin p li lm cho php bn thm cm gic b mt c gp ghnh.

p khong cch: cho php bn thm khong cch thc n b mt ti thi im render v s l nay c th lm gim s cn thit cho vic to nhng m hnh phc tp.

b) Cc cch p vt liu:

p kiu normal: Khi bn p mt texture 2D bn c th chn cc k thut p texture ln i tng l: normal, projection hoc stencil. Cc k thut p xt nh mi quan h gia texture v b mt. Mc nh texture c p kiu normal.

Texture c p vo h to UV ca b mt v xt nh kch thc v v tr tu thuc vo cc tham s UV ca tng b mt.

Shading network cho p texture 2D kiu nomalc to t node file texture v node place 2D texture (nh ngha v tr ca texture).

p kiu protection: K thut p ny bao ph texture thng qua mt khng gian 3D ging nh ph bao bc.

Khi bn to mt texture 2D bao ph th n phi ging texture 3D ( n phi c chiu cao, b rng v chiu su.

Shading network cho kiu p Projection 2D texture to ra node file texture v node projection (nh ngha v tr ca texture).

p vt liu kiu stencil : k thut ny cho php bn s dng cc file n hoc cc mu chnh b mt phn texture. Nu nhn ca bn khng phi l hnh vung, bn sa texture bng cch dng mt bn che b nhn bng cch s dng cc file che du hoc dng nhng mu trng vi texture. Sau dng Color Balance > Default Color ca texture gn hoc p mu che nhn .

Shading network cho p texture Stencil 2D to ra node texture v node Stencil (node ny nh ngha vic n) v 2 node placDtexture( 1 cho texture v mt cho stencil).

c) V tr ca texture 2D v 3D: Mt node 2D placement trong shading network nh ngha v tr v hng ca texture trong h to UV ca geometry.

Node 2D placement c th c to ra trc tip t h to UV ca b mt hoc gin tip thng qua node projection( nu texture c p theo kiu projection).

Bn c th thc hin t l, di chuyn hoc quay place2Dtexture thay i lm cho texture xut hin tren b mt nh th no. Cc gi tr khc nhcoverage v default color cho php bn nh ngh khong bao nhiu phn ca b mt c bao ph bi khung texture v mu cu ng vin xung quang texture( gi tr ny ch thc hin khi thuc tnh coverage nh hn 1).

V tr ca node shared 2D texture: Cc texture khc c th ni n 1 node place2Dtexture cho nn chng c t ti cng v tr. Nu thay i node place2Dtexture th s nh hng n tt c cc texture ni n n. Theo ngh th cc texture chia s dng chung vi p color,bump, specularity th cn mt v tr chnh xt.

V tr ca texture 3D:

Node 3D placement nh ngha v tr v hng ca texture 3D hoc texture Environment. Cc node 3D placement lm cho vic thc hin d p texture cho nhiu b mt nu cc b mt ny c cng texture.

Bn c th thay i v tr ca cc texture 3Dbng mt s trong Attribute Editor ca node place3Dtexture hoc bn c th dng cc k nng thay i v tr ca texture cng nh nhn.

Maya cung cp 2 cch thay i v tr ca texture 3D l trn cc b mt NURBS (Interabtive Placement) hoc Fit. Chn phng php no ph hp vi nhng yu cu cn thit ca bn. i khi s dng c 2 cch l tt hn.

Khi bn to hoc lm vic texture 3D trn mt i tng th biu tng cure-shaped xut hin trn mng hnh thc hin thay i kch thc, t l v nh li v tr ca texture trn b mt. c bit khi bn thc hin chuyn ng hoc lm bin i i tng th bn cn duy tr mt v tr texture hp l trn i tng.

d) p nhn: Mc nh cng c Texture Placement khi gn Label Mapping (label mapping cho php bn di chuyn, quay, ko di ra hoc thu ngn texture li nu texture l nhn. bn c th thay i khi to cho cng c Surface Placement ( cng c ny cho php bnthc hin ko gin, co li, di chuyn, quay texture nu texture l giy dn.

Trong c 2 trng hp th trc U v trc V dng canh v tr ca texture theo chiu ngang v chiu dc.

thay i cng c Texture Placement th nhp p ln biu tng Texture Placement Tool trong toolbal hoc chn Texturing > NIRBS Texture Placement Tool - V tr ca b mt: Khi bn drag bn tay th cc thuc tnh Repeat UV, Offset v Rotate UV thay i trong Attribute Editor ca place2dTexture. iu ny cho php bn ko di, thu ngn, di chuyn, quay texture nu texture l giy dn.

p nhn: Khi bn drag bn tay th cc thuc tnh Repeat UV, Offset v Rotate UV thay i trong Attribute Editor ca place2dTexture. iu ny cho php bn ko di, thu ngn, di chuyn, quay texture nu texture l nhn.

g) Cng c Transferring Surface Information.

- Bn c th truyn cc thuc tnh ca b mt ny n texture c p ln b mt khc. ng dng thng thng ca cng c ny l trong lnh vc ng dng theo thi gian thc ( cc ng dng thi gian thc mt vi chi tit b mtF. Thm m thanh vo hot cnh. Khi to mt hot cnh bn mun nghe mt m thanh c thu thm mt cch ng thi cc v tr kho vi mt thi im ca m thanh thu. Kho chnh l nhng nh du dng nh ngha thi im v s di chuyn ca hot cnh.

PlaybackSpeed phi c gn theo thi gian thc dng c th t play m thanh.

Khi mt file m thanh c load vo trong khung cnh th node audio c to ra vi tn node trng vi tn tp tin m thanh. Node audio tham chiu n v tr ca file m thanh. Nu bn thanh i v tr ca file m thanh th bn cn phi thay i thamchiu n v tr file cho node audio ca bn.

Fcheck c th import cc file m thanh v play ccfile m thanh ny ng thi vichui hnh nh. import file m thanh chn File > Import Sound. m tc m thanh th chn File > Toggle Sound.

Mc d bn c th import nhiu file m thanh cng lc nhng ch mt file c hin th v play ti mt thi im tren Time Slider.

laod mt file audio vo khung cnh th bn lm 1 trong cc thao tc sau:

S dng File > Import trnh duytn file cho php bn chn tn ca file m thanh mun import.

t file trn desktop v drag file vo trong khung modeling ca Maya.

nh v file trn desktop v drag file vo trn Timer Slider. Cc ng ca sang m thanh c hin th tren Time Slider v Timer Slider play xo m thanh.

hin th m thanh trn Time Slider:

Click chut phi ln Time Slider th menu pop-up xut hin.

Trong menu pop-up chon file audio mun nghe t Sound > tn file.

Hnh sng m thanh ca file audio hin trn Time Slider v n play trong sut thi gian pht m.

tip tc s dng cc file audio trong hot cnh. Gi s hot cnh ca bn bt u vi cc tia chp, sau play m thanh ca sm sau kt thc vi m thanh ma ri. Bn c 2 file khc nhau thunderstorm.aiff v rainstorm.aiff. Sau y m t nh th no import v play 2 file m thanh sau hot cnh. To hot cnh c sm st.

import cc file m thanh, m ca s ni bn dt file m thanh, sau drag file thunderstorm.aiff vo Time Slider. Node thunderstorm audio c to ra v bn s thy cc sng m thanh trn Time Slider. Drag file rainstorm.aiff vo trong khung nhn mng hnh. Node rainstorm audio c to ra. Time Slider vn tip tc hin th m thanh ca thunderstorm. Hot cnh s bt u vi 3 giy cho cc tia chp, m thanh ca thunderstorm bt u sau giy th 3. Chn Display > Sound > thunderstorm v thay i Start Time thnh 72 ( ti giy th 3 v mc nh l 24 hnh trn 1 giy). Bn s thy sng m thanh ca thunderstorm xut hin bt u ti 72. thc hin play hot cnh vi m thanh m ca s Animation Preferences v gn Playback Speed c khi gn l Real-time (24hnh/s) v click Play. Ting ma xut hin ti giy th 5 ( hoc ti thi im 120 trn Time Slider).

M ca s Display > Sound > raintom v gn Start Time l 120.

Nhn nt Play nghe v xem hot cnh ca bn. xem hot cnh ca ln vi c 2 loi m thanh th bn s render hot cnh ca bn thnh video v thu tng m thanh vo bng t.