Us ing Yafray in profe s s ional e nvironm e nt.

Le arn h ow to us e Sunflow re nde ring s y s te m .

Yafray caus tics e xplaine d.

Le arn m ore about Yafray G I.

D PI de m y s tifie d

Re nde ring optim ization.

EDITORGaurav Naw ani

MANAGING EDITORSandra Gilbe rt

W RITERSSandra Gilbe rtClaas Eick e Kuh ne nDanie l LaBargeCh ris toph e r KullaZ s olt Ste fan

DESIGN & GRAPH ICSGaurav Naw ani

W EBSITE DESIGNNam Ph am

COPYRIGH T© ‘Ble nde rart Magaz ine ’, ‘ble nde rart’ and ble nde rart logo are copyrigh t Gaurav Naw ani. ‘As k Ble ntuu’ and ‘ble ntuu logo’ are copyrigh t Sandra Gilbe rt. All products and com pany nam e s fe ature d in th e publication are trade m ark or re gis te re d trade m ark of th e ir re s pe ctive ow ne rs .

w w w .ble nde rart.org

CO NTENTS

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3ED ITO RIA L

You’ve s tudie d all th e tutorials , you built th e pe rfe ct m ode l, adde d th e pe rfe ct m ate rial, now its tim e to re nde r your w ork of art. You h it th e big “Re nde r” button, w ait for w h at s e e m s lik e fore ve r . . . and w h e n it finally finis h e s . . . w e ll to be h one s t, th e e nd re s ult look s noth ing lik e w h at you h ad im agine d. W h at w e nt w rong?

Mos t lik e ly, q uite a bit w e nt w rong. Re nde ring is th e re s ult of e ve ryth ing th at cam e be fore and as s uch th e re are a lot of factors th at can m ak e or bre ak you final im age . Is your ligh ting jus t righ t, are your s e ttings corre ct, did you account for all th e s pe cial e ffe cts you adde d. Eve n if you ge t all th e above righ t, you m igh t s pe nd h ours or days w aiting for th e final re nde r to finis h , only to dis cove r you ne e d to tw e ak s om e th ing jus t a little .

W e lcom e to Is s ue #3 “Re nde ring”. In th is is s ue w e w ill be cove ring s om e of th e is s ue s th at affe ct your final re nde r, bringing clarity and be tte r unde rs tanding to ach ie ve th e be s t re nde r pos s ible .

In addition to look ing into th ings th at can im prove your re nde rs , w e w ill als o look at w ays to de cre as e your re nde r tim e s as w e ll as tak e a look at s om e of th e Re nde r e ngine s available for Ble nde r. Of w h ich q uite a fe w h ave be e n de ve lope d re ce ntly and w arrant a look s e e .

W e als o h ave 3 s e parate article s on h ow to us e Yafray, w ith e ach s h ow ing a diffe re nt te ch niq ue and m e th od of us e .

Ch e e rs !Sandras andra@ ble nde rart.org

4Ble ntuu s ay s

Re nde ring is an ofte n m is unde rs tood proce s s and until w e ge t th e “m ak e re nde r be autiful button” ;) code d, w e h ave to do it th e h ard w ay. And th at w ould be by unde rs tanding w h at goe s into a re nde r and w h at affe cts th e re nde ring proce s s .

Th e s h ort ans w e r is th at EVERYTH ING affe cts th e re nde ring proce s s . Th at w ould include m ate rials , ligh ting, s pe cial e ffe cts and th e s ce ne its e lf. And w h ile dis cus s ing re nde ring could fill a w h ole book , for th is article w e are going to tak e a look at tips and trick s th at can incre as e or de cre as e your re nde r tim e s and q uality.

W h e n it com e s to re nde ring, s om e th ings jus t tak e longe r. If you jus t h ave to h ave th at ce rtain e ffe ct, by all m e ans go for it, but e xpe ct to w ait a w h ile for your re nde r to com ple te . H e re is a lis t of s om e th ings th at are liable to incre as e your re nde r tim e : Raytracing, Am bie nt Occlus ion Ligh ting Se tups H e avy us e of particle s Extre m e ly de taile d s ce ne s

On th e oth e r h and, CG art is full of trick s and w ork -a rounds to low e r re nde r tim e s , s uch as th e us e of th e fak e GI dom e . Long us e d in ble nde r be fore AO w as code d into ble nde r. It is s im ple to s e tup, e as y to adjus t and not as com putation h e avy as th e AO option.

To s e t one up is e as y: Add>Me s h >Icos ph e re , s ubdivis ion 2 De le te th e bottom h alf of th e Icos ph e re Add a s pot ligh t, and pare nt it to th e Icos ph e re H it F7, (Obje ct Se ttings w indow ) W ith th e Icos ph e re s e le cte d, pre s s th e duplive rt button.Se le ct th e s pot ligh t and adjus t th e Ene rgy w ay dow n (around .01) Adjus t th e re s t of your s e ttings as ne e de d to ge t th e am ount of ligh t and s h adow you are look ing for.

Oth e r th ings th at can low e r re nde r tim e s : Ge ne rally us e z -buffe r lam ps ove r raytrace d one s . Se t th e s am ple s and s h adow buffe r as low as pos s ible for th e q uality you look ing for.

Sim ilarly, turn th e s am ple s dow n on e ve ryth ing as low as you can ge t aw ay w ith th at pe ople probably w ill not notice (ligh ts , s ubs urf, rayde pth , e tc.).Re nde r in pas s e s w h e n pos s ible , you can re -com pos ite th e pas s e s in GIMP or Ph otos h op, not only w ill it low e r re nde r tim e s , you w ill h ave m ore control ove r h ow e ach laye r goe s toge th e r w ith th e oth e rs .

Only m ode l th os e de tails th at are ne e de d, UV m apping and prope r us e of te xture s can s ave on your polygon count. W h e n it is all s aid and done , us e only th os e options and te ch niq ue s th at

you actually ne e d to m ak e your im age or anim ation look good. If you can ch e at or fak e it, th e n do s o, it w ill s ave on your re nde r tim e s . If you jus t h ave to us e it, th e n be pre pare d for th e w ait. W h ile w aiting I s ugge s t re laxing w ith a nice cup of coffe e and a good book .

5NEW S Flas h

Th e bigge s t e ve nt in th e Ble nde r w orld is jus t around th e corne r. Proje ct Orange is ne ar com ple tion and th e pre m ie r of “Ele ph ants Dre am ” h as be e n s ch e dule d for March 24, 2006. Cine m a Ke te lh uis , a w e ll k now n cine m a for docum e ntarie s and art-h ous e m ovie s in Am s te rdam , h as be e n ch os e n as th e location for th e long aw aite d pre m ie r.

Th e cine m a ope ns at 17:30 and th e s h ow ing w ill s tart at 18:00. In addition to th e s cre e ning of “Ele ph ants Dre am ”, th e re w ill als o be a pre vie w of th e “Mak ing of” docum e ntary. If you m is s th e firs t s h ow ing, th e re w ill be anoth e r at 18:45.

Afte r th e pre m ie r, th e re is a ce le bration planne d at one of th e h ippe s t nigh tclubs , ironically nam e d “Ble nde r”. W h ile th e pre m ie r is fre e of ch arge , th e re is an e ntrance fe e to th e “afte r party”.Saturday 25 and Sunday 26 March , th e Proje ct Orange te am w ill be on h and all

day in Monte vide o (K e iz e rs grach t 264, Am s te rdam ) for furth e r vie w ing and dis cus s ion of th e proje ct. For m ore inform ation on th e pre m ie r and th e follow ing pre s e ntations of th e m ovie ch e ck h ttp://orange .ble nde r.org/.

Ble nde r h as be com e an e ve r ch anging program , w ith ne w fe ature s cons tantly be e n w ritte n and re vis e d for be tte r and cle ane r functionality. Ove r th e las t tw o m onth s , m ajor coding e ffort h as be e n focus e d into th e “Noodle s ” s ys te m (node e ditor) and th e re nde r e ngine . Th e Noodle s s ys te m allow s for th e cre ation of h igh ly advance d m ate rials and com pos iting e ffe cts . Th e re nde r e ngine is be ing s tre am line d and m odifie d to w ork cle ane r and m ore e fficie ntly, allow ing for fas te r and m ore e rror fre e re nde ring.To ch e ck a te s t build w ith th e s e ne w fe ature s , drop by th e te s t build forum at w w w .ble nde r.org.

Since th is is s ue is focus ing on re nde ring, th is is a good tim e to e xplore all th e re nde r e ngine s available for us e w ith

ble nde r. In addition to YafRay, POV-Ray, Me gaPOV, th e re are now e xport s cripts available for th e follow ing ne w e ngine s :

Ke rk yth e aSite : h ttp://w w w .s oftlab.e ce .ntua.gr/~ jpanta/Graph ics /Ke rk yth e a/

SunflowSite : h ttp://s unflow .s ource forge .ne t/

IndigoSite : h ttp://h om e page s .paradis e .ne t.nz /nick am y/indigo.h tm l

3De ligh tSite : h ttp://w w w .3de ligh t.com /

Me tropoligh tSite : h ttp://w w w .3dvirtualigh t.com /m lt/

6W O RK SH O P 3D - Profe s s ional D igital Studio Re nde ring w ith H D RI IBL and G I

IntroductionA good im age is w orth a th ous and w ords in Indus trial de s ign indus try. Ble nde r h as be com e an e s s e ntial tool for m y w ork , be caus e it allow s m e to vis ualiz e an ide a w ith gre ate r fle xibility th an any h and s k e tch , and th us vis ually com m unicate s m y de s ign and conce pt. W h ile Ble nde r is not m ade for CAD/CAM and lack s m any fe ature s th os e pack age s fre q ue ntly include , it is s till pos s ible to us e it not only for product re nde ring, but als o, to s om e de gre e , th e w h ole de s ign proce s s .

Part 1: Mode lingAs an obje ct de s igne r w ith a re ce nt focus on m e tal s m ith ing, Ble nde r provide s m e w ith all th e ne ce s s ary m ode ling tools to de s ign, e xplore , and cons truct m y obje cts . Th e Polygon tools , toge th e r w ith Subdivide d Surface s , allow m e to m ode l all s h ape s , w h ich I w ould late r be able to cons truct in m e tal w ith m y h ands . In s ilve r s m ith ing, m os t s h ape s are cons tructe d out of s h e e ts , w ire , and tubing. Ele m e nts can be be nt by h and or forge d ove r s h ape s and th e n s olde re d toge th e r. Th is m e ans th at I m ainly de al w ith ge om e tric

prim itive s h ape s . And th os e are ve ry e as y to m ode l in ble nde r. Th e re ce nt addition to calculate th e le ngth and angle e dge s furth e rs m y ability to account for corre ct m e as ure m e nts and dim e ns ions . Th is is one of th e m os t im portant advantage s 3D m ode ling can provide you, be caus e you h ave th e pos s ibility to w ork in corre ct proportions and dim e ns ions . Sm all ch ange s w ith in th e de s ign or a ch ange of th e point of vie w can be ach ie ve d w ith a fe w m ous e click s and do not re q uire th e h and s k e tch to be com ple te ly re draw n. (Scre e ns h ot: Me as ure m e nts )

In addition, not only doe s Ble nde r allow to m ode l m e ch anical e le m e nts , it als o m ak e s it pos s ible to anim ate th e m , allow ing m e to proof

th e conce pts and trouble s h oot pos s ible proble m s . In Orth ograph ic Vie w , s cre e ns h ots can be tak e n of th e w ire fram e and com pos e d toge th e r. Afte r printing on pape r th e y can be cut out and glue d onto th e s ilve r s h e e t, to aid as guide s for th e s h ape s I s aw in th e m e tal. W ork ing in laye rs aids a lot in th is proce s s be caus e e le m e nts can be dis tribute d th rough th e m and th e n s e le ctive ly s h ow n to cre ate cle ar and us e ful s cre e ns h ots . (Scre e ns h ots : Outline s )

7W O RK SH O P 3D - Profe s s ional D igital Studio Re nde ring w ith H D RI IBL and G I

Part 2: Te xturingTh e curre nt ve rs ion of Ble nde r and Yafray s upport m os t te xture s and s urface ligh t m ode ls th at an artis t ne e ds to cre ate pre -conce ive d m ate rial s im ulations . H ow e ve r s pe cific m ate rials lik e brus h e d m e tal or trans luce nt m ate rials are s till e ith e r not ye t pos s ible or only pos s ible w ith additional trick s and tim e . Spe cifically in m y cas e , I am unable to acq uire th os e anis otropic re fle ctions and s pe cular h igh ligh ts , w h ich are re q uire d to accurate ly s im ulate th e fine -brus h e d s urface s w ith w h ich I w ork . But to s om e de gre e th is fe e l can be ach ie ve d by us ing a proce dural nois e m ap or a painte d bum p m ap.

Th e proble m is th at you can only re ach a ce rtain am ount of de tail be fore you w ill run into m oir patte rns during re nde rings . H ow e ve r e ve n a s om e w h at coars e bum p m ap alre ady provide s e nough de tail to s im ulate a brus h e d s urface . Th e te xture ne e ds to be s tre tch e d along one axis and ne e ds to h ave th e righ t s cale . (Scre e ns h ots : Prode cural te xture 1+ Te xture 2)

Als o, a s m all color tint for th e re fle ctions and h igh ligh ts w ill re duce th e s te rile look of raytrace d re fle ctions a lot and at th e s am e tim e give th e re nde ring a fe e ling w h ich I am us e d to ge tting from us ing re al s tudio lam ps . Th os e lam ps do not produce w h ite ligh t. Th e ligh t is alw ays a bit ye llow . It w as als o im portant to give th e ground plane a diffe re nt color th an plain black . Th os e h ue value s w e re ve ry m inim ally diffe re nt from pure black but e nough to cre ate a natural look .

Part 3: Re nde ringFor m y re nde rings , I h ave th e e xpe ctation th at th e final re s ult s h ould be as re alis tic as pos s ible . I us e Yafray as th e prim ary re nde r e ngine , be caus e it s upplie s m e w ith H DRi ligh ting, Global Illum ination, Color Ble e ding,

Caus tics , and true De pth of Fie ld. Spe cifically for m y type of w ork re nde rings , w h ich m im ic

th e ae s th e tics of s tudio s h ots , th e s e fe ature s are e s s e ntial in com m unicating w h at m y w ork is about. H DRi IBL can provide th e prope r natural ligh t diffus ion and coloriz ation, w h ich are s ough t in obje ct s tudio ph otograph y. In m y cas e , I us e an H DRi file w h ich contains only tw o ligh t are as , s im ulating th e diffus e d ligh t w alls .

Th is w ill produce e xtre m e ly s oft s h adow s and re duce th e am ount of burning h igh ligh ts . Th is ligh t probe s upplie s th e de s ire d am ount of ligh t from th e prope r dire ction in th e s ce ne , w h ile e lim inating any unw ante d re fle ctions (or h ot s pots ) on th e w ork . Th e H DRi ligh t m ap (be low ) w ill furth e rm ore not only illum inate th e front vie w of th e obje ct, but als o e m it e nough low k e y ligh t to illum inate th e m e tal w ork from all oth e r dire ctions . Th is e lim inate s any ne e d for s m all ligh t arrays to brigh te n up s pe cific are as , lik e th e traditional th re e -k e y ligh t s e tup.

8W O RK SH O P 3D - Profe s s ional D igital Studio Re nde ring w ith H D RI IBL and G I

Furth e rm ore , th e GI option not only accounts for a prope r s h adow calculation and illum ination of th e w h ole ge om e try, but als o incre as e s th e re alis m of th e re nde ring w ith calculating color ble e ding and caus tics . Many product re nde rings lack th os e fine de tails ne e de d. Ofte n, it is th os e fine de tails th at w ill h ave a s ignificant im pact on th e vie w e r w ith th e re alis m fe lt w h ile vie w ing th e re nde rings .

But jus t s e le cting an H DRi ligh t m ap is not alw ays e ve ryth ing you can do. In m y s ituation, I only ge t ligh t from one s ide . Be caus e of ae s th e tic re as ons , you w ant to e lim inate or ligh te n th e dark are as s o as to incre as e th e ove rall dynam ic range of th e re nde ring. To brigh te n up s h adow s and dark are as , w h ite ligh t re fle ctors are us e d in re al life ph otograph y. Sam e trick applie s to digital re nde ring w ith GI.

Th e follow ing tw o s cre e ns h ots cle arly s h ow th e diffe re nce . Th e GI calculate s not only th e ligh t com ing from th e H DRi m ap, but als o calculate s th e ligh t bounce d back by th e ligh t re fle ctors and th is brigh te ning up of th e s h adow s on th e cigare tte s als o adds m ore de tail to th e m e tal re fle ctions . As you als o can s e e , I us e a ch rom e ball to find out w h e re th e ligh t is com ing from , th at inform ation e nable m e to pos ition th e m e tal w ork corre ctly in th e s ce ne .

Re nde ring: ch rom e ball_ te s t

Sce ne : Topvie w

Sce ne : s e tup3D Anoth e r ve ry im portant tool for product s h ots is th e De pth of Fie ld. Th is fe ature s is ve ry us e ful in attracting atte ntion to th e s pe cific e le m e nts of m y w ork , w h ile oth e r e le m e nts are blurre d. Yafray s upports true DoF, w h ich w ith h igh e r s am ple value s w ill produce ve ry s m ooth re s ults . Th e re nde r tim e w ill obvious ly incre as e w ith th e am ount of s am ple s , but th e e nd re s ult is m ore th an w orth it. Th e DoF s e ttings can be acce s s e d from w ith in Ble nde r. An ape rture value of 0.1 to 0.5 is s ufficie nt. To gain a s m ooth DoF re nde ring, in th e re nde r s e ttings you ne e d to dis able auto AA. De pe nding on th e s ce ne you h ave to adjus t th e AA s e ttings , in m y s ce ne I us e d 15 * 15 for AA Pas s e s and AA Sam ple s .

Scre e ns h ots ne xt page : AA Se ttings + DoF_ s e tup

9W O RK SH O P 3D - Profe s s ional D igital Studio Re nde ring w ith H D RI IBL and G I

For je w e lry re nde rings , I pre fe r a te xture d ground. One of m y re ce nt w ork is s h ot on a black , s e m i-re fle ctive s urface , w h ich h as a fine grain te xture . A com m on m is tak e m ade in s im ulating th is e ffe ct is to s e le ct a too s trong re fle ctive value . Th e re fle ction on th e picture ground s h ould only be s ligh tly vis ible , s o it accom panie s th e m ain obje ct and pre ve nts from appe aring as a floating obje ct. Additionally, too s h arp re fle ctions w ill only dis tract th e vie w e r and s te al atte ntion aw ay from th e w ork .

Th e re are tw o pos s ible w ays to ach ie ve th is

re s ult.

Dirty one , Ble nde r inte rnal:Th e re fle ction can be diffus e d w ith a fine nois e m ap in th e norm al ch anne l. Th is is a q uick w ay to cre ate blurre d re fle ctions , th ough th e y are not ph ys ically corre ct. In th is cas e , be caus e th e re fle ction s h ould not ge t too m uch atte ntion, th is proble m is not of any m ajor s ignificance .

Cle an one , YafrayYafray its e lf s upports th e bas ic fe ature s of blurre d re fle ctions . Unfortunate ly, th is fe ature is not acce s s ible from w ith in Ble nde r inte rface . You ne e d to m anually e dit th e e xporte d XML file and th e n re nde r from Yafray. Furth e rm ore

Re nde ring: true _ blurre d_ re fl_ nobum p

Yafray doe s not s h ow s blurre d re fle ctions in oth e r re fle ctions , w h ich m igh t be in s om e s ituations a lim itation.

To e xport th e s ce ne into an XML file , all you ne e d to do is to e nable th e XML e xport, s tart to re nde r, and s top Yafray th e m om e nt it is finis h e d w ith loading th e s ce ne and s tarting to re nde r(ch e ck th e te rm inal w indow for th is during re nde ring). Ope n th e XML file in any te xt e ditor and e nte r th e follow ing s h ade r inform ation into your XML file .

10W O RK SH O P 3D - Profe s s ional D igital Studio Re nde ring w ith H D RI IBL and G I

Firs t include th e cone trace s h ade r at th e be ginning of your xm l docum e nt afte r th e <s ce ne > tag.

Th e s am ple value w ill de fine h ow fine th e blurre d re fle ction is . H igh e r value s above 10 produce th e de s ire d s m ooth re s ult in m y s ce ne .

But th is als o de pe nds on th e dis tance be tw e e n your cam e ra and th e obje ct. In clos e -ups h igh e r value s are ne e de d.

W h e n you us e th e cone trace s h ade r, you can dis able th e re fle ction prope rtie s ins ide ble nde r.In th e ne xt s te p you add "<e nvironm e nt value ="e nv" />" ins ide th e m ate rial s h ade r block you w ant to be re fle ctive . Se e code box on righ t.

Afte r th is s te p, and s aving th e file , all you ne e d to do is to le t Yafray re nde r th e xm l file . For m y conve nie nce I cre ate d a s h ortcut to Yafray.e xe . I only drag and drop th e xm l file on th e s h ortcut icon and th e re nde r proce s s s tarts autom atically.

But th is w ill re s ult in tw o proble m s : Firs t w ith us ing a nois e m ap you w ill e nd up w ith h aving th e nois e patte rn e ve ryw h e re on th e ground plane . And th e nois e m ap doe s not cre ate th e de s ire d s urface te xture I am look ing for. Se e re nde ring: fak e bum p re fle ction on pre vious page .

Se cond, w h e n you only us e blurre d re fle ctions re nde re d by Yafray you e nd up w ith a s urface

only s h ow ing th e re fle ction but not s tructure . Se e re nde ring: true blurre d re fle ction on pre vious page .

In m y final re nde r I le t Yafray re nde r th e blurre d re fle ctions but I als o adde d a ve ry fine s tucci bum p m ap to th e norm al ch anne l of m y ground plane . Th is w ill re s ult in firs t a ve ry nice blurre d re fle ction re nde re d by Yafray and th e s tucci bum p m ap w ill give th e ground plane th e de s ire d s urface s tructure . Th is w ill incre as e th e re nde r tim e a lot. In cas e you h ave a w e ll w ork ing bum p m ap for th e ground plane , it m igh t not be ne ce s s ary to us e th e true blurre d re fle ction w ith in Yafray s cre e ns h ots of s tucci bum p m ate rial.

<shader type="conetrace" name="env" reflect="on" angle="10" samples="16" > <attributes> <color r="0.5" g="0.5" b="0.5" /> </attributes></shader>

<shader type="blendershader" name="MAMaterial.002" >

<attributes><color r="0.800000" g="0.800000" b="0.800000" />

<specular_color r="1.000000" g="1.000000" b="1.000000" /><mirror_color r="1.000000" g="1.000000" b="1.000000" />

<diffuse_reflect value="0.800000" /><specular_amount value="0.500000" />

<alpha value="1.000000" />

<emit value="0.000000" /><matmodes

value="traceable shadow" /><diffuse_brdf

value="lambert" /><specular_brdf value="blender_cooktorr" />

<hard value="50" />

<environment value="env" /></attributes>

11W O RK SH O P 3D - Profe s s ional D igital Studio Re nde ring w ith H D RI IBL and G I

You h ave to play a bit w ith th e re fle ction value s and th e m ate rial prope rtie s be caus e e ve ry ch ange for th e re fle ctions w ill als o alte r th e re nde re d color for th e ground plane . At firs t th e re fle ction and s tucci m ap w as too s trong and dis tracting.

In th e las t re nde ring I low e re re d th e re fle ction value as th is als o low e re d th e e ffe ct of th e s tucci bum p m ap.

Conclus ionW h ile Ble nde r lack s m any im portant m ode ling tools for CAD/CAM, th is proje ct cle arly s h ow s th e s tre ngth of Ble nde r as a m ode ling and de s ign tool and Yafray as a ph otore alis tic re nde r e ngine . Both are pow e rful e nough to be tak e n s e rious ly by artis ts w h o w ork in a s e m i CAD/CAM-lik e e nvironm e nt s im ilar to th e one th at I w ork in and w h o ne e d a w e ll balance d

s e t of m ode ling, anim ation, and re nde ring tools for th e vis ualiz ation. Be caus e all m y s h ape s are h and crafte d, I do not ne e d any tool w h ich is re q uire d for rapid prototyping. Als o, com ple x m ode ls can be im porte d from oth e r applications to be te xture d in Ble nde r and th e n re nde re d in Yafray.

In te rm s of ph otore alis tic output, Yafray alre ady outpe rform s s om e of th e indus try s olutions available as long as you us e it righ t.Th is can be s e e n as a proof of conce pt th at Ope n-Source s oftw are can re alis tically com pe te w ith com m e rcial s oftw are s olutions . W h ile th e re are of cours e re nde r and m ate rial fe ature s Ble nde r and Yafray cannot s upport at th e m om e nt, it is im portant to k e e p in m ind th at both program s are curre ntly unde rgoing a s e rious re cons truction.

Ble nde r is ge tting a ne w node -bas e d m ate rial s ys te m and Yafray continue s to im prove th e ph ys ical accuracy in re nde ring. As an artis t, I h ope th at fe ature s alre ady pre s e nt in Yafray (s uch as blurre d re fle ctions ) w ill be furth e r inte grate d and m ore acce s s ible from Ble nde r. Th os e m ate rial and re nde r options not only incre as e th e pote ntial of th is s oftw are com bination, but continue to clos e th e gap be tw e e n Ope n-Source and com m e rcial s oftw are .

12W O RK SH O P 3D - Profe s s ional D igital Studio Re nde ring w ith H D RI IBL and G I

Th e re al fork m ode l (ph otograph )

13W O RK SH O P 3D - Sunflow Re nde ring Sy s te m Tutorial

IntroductionIn th is tutorial, I w ill pre s e nt s om e of th e bas ic fe ature s of Sunflow and h ow to us e it from Ble nde r.

Sunflow is m y ope n s ource re nde ring s ys te m . It is built around a s m all but ve ry fle xible core w h ich allow s it to be com ple te ly cus tom iz e d. It contains s e ve ral m ode rn algorith m s th at m ak e it a good candidate for ge ne rating re alis tic im age s . It h as be e n re ce ntly conne cte d to Ble nde r via a s im ple e xport s cript w h ich I w ill be de s cribing.

Ins tallationSunflow is w ritte n in Java. Th is m e ans you w ill ne e d to dow nload and ins tall th e Sun JRE (or JDK) if you don't h ave it alre ady. Go to h ttp://java.s un.com / and follow th e ins tructions for your particular ope rating s ys te m (OS X us e rs w ill ne e d to go to th e Apple w e bs ite ). Sunflow re q uire s Java ve rs ion 5 (s om e tim e s calle d 1.5) or h igh e r.

Once you are s e tup, go to a com m and prom pt and type : java -ve rs ion

If th e corre ct ve rs ion num be r appe ars

e ve ryth ing is s e tup corre ctly.

Ne xt, ge t th e binary re le as e from th e Sunflow w e bs ite (v0.05.5 at th e tim e of th is w riting) and unz ip it to a dire ctory of your ch oice . Go to th at dire ctory in com m and line m ode and type th e com m and line de s cribe d in th e README file include d in th e dis tribution. You s h ould s e e th e follow ing w indow appe ar:

Finally, ge t th e ble nde r e xporte r s cript from th e Sunflow w e bs ite and ins tall it into to your ble nde rs (Ins ide your ble nde r ins tallation folde r) s cripts folde r. Ne xt w h e n you s tart Ble nde r you s h ould s e e an option appe ar in

th e File ->Export m e nu as follow s :

You are now re ady to re nde r your firs t im age !

Firs t Re nde r: A m bie nt O cclus ionI h ave pre pare d a ve ry s im ple s ce ne h e re for illus tration purpos e s . Fe e l fre e to follow along w ith your ow n favorite m ode l. H e re is w h at m y s ce ne look s lik e in th e 3D vie w :

14W O RK SH O P 3D - Sunflow Re nde ring Sy s te m Tutorial

Go to th e File -> Export and pick th e Sunflow Exporte r you jus t ins talle d. It w ill bring up th e follow ing UI in th e s cript w indow :

W e are jus t going to ch ange a fe w s e ttings th e firs t tim e around. Our goal is to do a s im ple am bie nt occlus ion re nde r to ge t a fe e l for th e proce s s . Don't w orry about th e m any diffe re nt s e ttings you s e e , w e w ill cove r m os t of th e m s oon.

In th e AO Ove rride tab, click th e 'Am b Occ' toggle . Th is is s im ply te lling th e e xporte r th at w e w ant to ove rride all s h ading in th e s ce ne w ith th e pre s cribe d am bie nt occlus ion s h ade r.

Th e m os t im portant options are s am ple s (num be r of rays trace d to calculate th e occlus ion) and th e dis tance s e tting (h ow far to look for oth e r obje cts ).For now , le ave th e num be r of s am ple s as it is , and s e t th e dis tance to a re as onable value for

your s ce ne . Th e de fault of z e ro corre s ponds to infinite ly long rays .

Now h it th e Export button and pick a location to put th e e xporte d s ce ne file . You can look at Ble nde r's output w indow to s e e th e s te ps th e e xporte r is tak ing. It m ay tak e a fe w s e conds to w alk th rough your s ce ne if you h ave m any obje cts . W h e n th e file is e xporte d you w ill be s e nt back to th e e xporte r options .

Now go to th e Sunflow w indow you launch e d e arlie r and ope n th e s ce ne file you jus t w rote out. If loading s ucce e ds w ith out e rrors , th e Re nde r m e nu option w ill now be e nable d.

Se le ct Re nde r -> IPR firs t. Th e im age w ill s tart re nde ring in a ve ry block y form and progre s s ive ly re fine its e lf. Afte r jus t a fe w s e conds , you s h ould alre ady s e e w h at th e final im age is going to be lik e . You m ay cance l th e re nde r at anytim e . In m os t cas e s , le s s th an 10% of th e im age is ne e de d be fore you are re ady to launch th e full re s olution re nde r.

Now s e le ct Re nde r -> Re nde r. Th e im age w ill re nde r in s m all buck e ts th is tim e . If you h ave a m ulti-proce s s or m ach ine you w ill s e e s e ve ral buck e ts re nde ring at once . Afte r a fe w

s e conds you s h ould s e e s om e th ing lik e th e s ce ne be low .

Congratulations ! You jus t re nde re d your firs t im age w ith Sunflow .

Your im age w ill probably be nois y and h ave m any s m all artifacts . Don't w orry. W e w ill le arn h ow to e nh ance th e q uality of th e im age s oon.

Now , le t's m ak e our s ce ne a bit m ore inte re s ting by adding s om e ligh ts and m ate rials to it!

15W O RK SH O P 3D - Sunflow Re nde ring Sy s te m Tutorial

Ligh ts and Mate rialsGo back to ble nde r and as s ign s om e uniq ue m ate rials to e ach s urface . K e e p in m ind th at th e e xporte r doe s not ye t s upport th e full range of Ble nde r s h ade rs and te xture s .

For now , w e w ill jus t be cre ating re gular diffus e m ate rials . For e ach m ate rial, s im ply as s ign a uniq ue color. Th is is th e only attribute th at is re ad by de fault, all oth e r options are ignore d. Th e re are a fe w e xce ptions to th is rule to ge ne rate oth e r Sunflow s h ade rs , but w e w ill cove r th e m late r on.

Ne xt, w e ne e d s om e ligh ts . Th e e xporte r curre ntly only s upports lam ps and s q uare are a ligh ts . Are a ligh ts w ill give you nice s oft s h adow s at th e e xpe ns e of additional re nde r tim e . My s ce ne w ith bas ic s h ade rs and ligh ts now look s lik e on th e im age at righ t.

Once you are h appy w ith your s ce ne , tim e to e xport again! Th is tim e , le t's try to unde rs tand th e various s e ttings and h ow th e y affe ct im age q uality.

Th e m os t im portant are probably th e AA s e ttings . Th e m in and m ax value s control h ow m uch com putation goe s into e ach pixe l. Ne gative value s m e an com putations w ill be inte rpolate d acros s s e ve ral pixe ls , pos itive value s m e an m ore calculations w ill be done pe r pixe l. Z e ro m e ans a s ingle com putation is done pe r pixe l. For e xam ple : th e de fault

value s of -2 and 0 m e an th at th e re nde re r w ill s tart by calculating e ve ry 4th pixe l, and adaptive ly calculate dow n to th e s ingle pixe l le ve l w h e re it is ne e de d. Th is tim e , try s e tting your AA value s to 0 and 2. Each pixe l w ill now be s h ade d at le as t once , and up to 16 tim e s (le ve l 2).

If w e calculate m ore th an one value pe r pixe l, w e w ill ne e d to ave rage th e m toge th e r. Th e w ay th is is done is controlle d by th e im age filte r s e tting. Le t's pick th e 'M itch e ll' filte r as it provide s a nice s h arpe ning of th e im age . Th is particular filte r h as a fixe d w idth and h e igh t, s o th os e s e ttings w ill dis appe ar from th e dialog w h e n it is s e le cte d.

Ligh t s e rve r s e ttings le t you control h ow m any rays are us e d pe r ligh t. Th e de fault of 16 is a bit h igh but us ually give s good q uality.

Th e GI tab controls global illum ination. Th is is an advance d topic w e w ill e xplore in th e ne xt s e ction. Le ave all th e controls at th e ir de fault value s for now .

Th e Acce le rator tab contains s e ttings w h ich h ave no im pact on im age q uality but can m ak e dras tic diffe re nce s in im age calculation tim e . Th e de fault acce le rator is th e k dtre e and is us ually

th e be s t ch oice .

You can e xpe rim e nt w ith diffe re nt acce le rator type s and s e e w h ich one provide s th e fas te s t re s ults for your s ce ne . You can als o adjus t th e buck e t orde r in th is tab. Sw itch to s piral th is tim e to h ave th e im age com pute d from th e ce nte r out.

16W O RK SH O P 3D - Sunflow Re nde ring Sy s te m Tutorial

Unde r th e ligh t tab, w e h ave th e option of adjus ting th e s tre ngth of all ligh ts in th e s ce ne . Since Sunflow us e s m ore ph ys ically bas e d calculations th an Ble nde r, th e ligh t pow e rs w ill not us ually m atch . Th is global s cale factor can h e lp you com pe ns ate for th is . I s e t m ine to 5, but th is w ill vary from s ce ne to s ce ne . Note th at th e s cale factor only affe cts are a ligh ts .

Finally, re m e m be r to de s e le ct th e 'Am b Occ' button from th e AO Ove rride tab if it w as s till s e le cte d from th e pre vious e xport.

W e can now e xport and re nde r again. If you e xport to th e s am e location as be fore (ove rw riting th e old file ), you can s im ply us e th e File -> Re -ope n m e nu option in th e Sunflow GUI to q uick ly re load your s ce ne .

Us e th e IPR fe ature again to s e e w h at your s ce ne look s lik e q uick ly. You w ill probably ne e d a couple of e xport cycle s be fore you ge t th e ligh t inte ns itie s jus t righ t. H e re is m y re s ult (Im age le ft bottom ).

De s pite th e s oft s h adow s , th is im age is n't ve ry re alis tic ye t. I w ill s h ow you h ow to addre s s th is in th e ne xt s e ction.

Global Illum ination Te ch niq ue sAs I m e ntione d in th e introduction, Sunflow is a ve ry cus tom iz able re nde re r. It is th e re fore able to incorporate m any diffe re nt GI algorith m s into one coh e re nt fram e w ork . Th is give s th e artis ts diffe re nt w ays to ach ie ve th e ir goals and m ak e s it pos s ible for de ve lope rs to introduce ne w algorith m s , w ith out bre ak ing olde r s ce ne s .

I w ill now brie fly de s cribe one of th e m e th ods of calculating global illum ination: path tracing. Th is is th e m os t accurate and e as ie s t m e th od to le arn. Th e catch is th at it can tak e q uite long to ach ie ve h igh q uality re s ults .In th e e xporte r, go to th e GI tab and e nable th e path button. Th e algorith m is controlle d by tw o param e te rs : s am ple s and bounce s . Th e firs t de fault to 32 and controls th e q uality of th e re s ult. Th e s e cond de fault to 1 and controls h ow m any bounce s th e ligh t is allow e d to m ak e .

Le ave th e value s at th e ir de faults for now to s e e th e ir e ffe ct. Since th is algorith m w ill produce ve ry nois y re s ults , go to th e AA tab and s e t both th e m in and m ax to 0. Th is w ill force only one s am ple to be tak e n pe r pixe l, w h ich avoids th e anti-alias ing from be ing force d to s upe r s am ple e ve ry s ingle pixe l be caus e of th e nois e .

You m ay als o w ant to s e t th e filte r back to box (w idth and h e igh t 1) to avoid introducing artifacts by filte ring th e nois e .

Export and re nde r again. I adde d s om e w alls be h ind m y s ce ne to s e e th e e ffe ct of th e bounce s . Com pare th e s e tw o re nde rs w ith and w ith out global illum ination:

Global illum ination re fe rs to m e th ods

w h ich are bas e d on ph ys ical com putation

of ligh ting in a s ce ne by tak ing into

account th e e ffe cts of ligh t bounce s on

and off th e 3d s urface s . It provide s th e

m os t re alis tic ligh ting s im ulation of in CG.

17W O RK SH O P 3D - Sunflow Re nde ring Sy s te m Tutorial

Sce ne w ith GI

Sce ne w ith no GI

Notice h ow th e s h adow e d re gions are no longe r com ple te ly dark and h ow w e obtaine d s om e s ubtle color ble e ding on th e floor

and be tw e e n th e obje cts .You m ay find it h ard to ge t rid of th e nois e in th e im age in a re as onable am ount of tim e , e ve n if you m ak e th e num be r of s am ple s q uite h igh . Th is is a th e ore tical lim itation of th e path tracing algorith m . Ph oton m aps and irradiance cach ing are tw o algorith m s th at w h e n com bine d can yie ld a m uch m ore e fficie nt s olution; h ow e ve r th e y are m uch trick ie r to s e tup, e ve n for e xpe rie nce d us e rs .

Rath e r th an go into th e de tails of th e s e advance d m e th ods , it m igh t be be tte r to k now th at s im ple r and m ore e fficie nt algorith m s e xis t th at w ill ve ry lik e ly appe ar in Sunflow s oon.

Im age bas e d ligh tingIn th is s e ction w e w ill cove r th e us e of H DRI e nvironm e nt m aps for ligh ting. Back in your ble nde r s ce ne , load in a longitude -latitude H DRI e nvironm e nt m ap as a te xture at th e w orld le ve l. Be s ure to unch e ck 're lative path s ' w h e n loading th e m ap. Re nam e th e te xture obje ct to 'iblligh t' as s h ow n. Th is le ts th e e xporte r k now you w ant to tre at th is m ap as an e nvironm e nt ligh t s ource .

Go ah e ad and h ide all th e ligh ts you w e re us ing be fore (th e e xporte r re s pe cts Ble nde r laye rs ), and m ak e s ure your s ce ne is 'ope n'. Th is type of ligh ting as s um e s th e ligh t is com ing from infinite ly far aw ay, s o its be s t s uite d to outdoor re nde rings . Indoor s ce ne s w ill pe rform ve ry poorly w ith th is te ch niq ue .

Sunflow approxim ate s th e e nvironm e nt m ap w ith a fixe d num be r of dire ctional ligh ts . Th is is controlle d by th e 'Dire ct s am ple s ' s e tting in th e e xporte r. Us ing th e de fault of 16 you w ill probably s e e s om e s h arp e dge s to th e s h adow s from th e individual ligh ts us e d. Sim ply incre as e th e num be r of ligh t s am ple s until th e s h arp s h adow boundarie s are de cre as e d to an acce ptable le ve l.

Exporting and re nde ring again, you s h ould e nd up w ith s om e th ing lik e th is :

18W O RK SH O P 3D - Sunflow Re nde ring Sy s te m Tutorial

Th is im age is q uite re alis tic, e ve n th ough w e h ave not us e d any global illum ination. Of cours e you m ay e nable path tracing as w e did be fore to s im ulate th e e xtra bounce s of ligh t.

Glos s y m ate rialsFinally, le t's m ak e our s h ade rs a little m ore inte re s ting. Up until now w e h ave us e d com ple te ly diffus e s h ade rs .

Le t's s tart w ith th e s h iny s h ade r. It s im ply adds a th in re fle ction coat on top of th e diffus e color. Re nam e one of your obje cts m ate rials s o th at its nam e s tarts w ith 's fs h iny'. Th e e xporte r w ill now re ad th e 'RayMirr' attribute to de te rm ine th e am ount of re fle ction to apply.

Ne xt is th e ph ong s h ade r w h ich provide s blurry re fle ctions . Re nam e th e m ate rial you w is h to e dit s o th at it s tarts w ith 's fph ong'. Th e s pe cular color now controls th e am ount of re fle ction w h ile th e 'h ard' value controls th e blurrine s s . H igh e r h ardne s s value s re s ult in s h arpe r re fle ctions . For m y s ce ne I us e d value s ranging from 5 to 50.

Now th at w e h ave adde d s e ve ral laye rs of re fle ctions , w e ne e d to pay atte ntion to th e 'Max De pth ' s e tting in th e e xporte r dialog. Th is controls h ow m any le ve ls of re fle ctions are allow e d. Th e de fault of 9 is rath e r h igh s o w e w ill re duce it to 3 th is tim e .

H e re is th e final re s ult, re nde re d w ith th e im age bas e d ligh ting from th e pre vious s e ction:

Conclus ionI h ope you've e njoye d th is q uick tour of s om e th e fe ature s of th e Sunflow re nde ring s ys te m .

One tutorial is not e nough to cove r e ve ryth ing th at is pos s ible w ith th is s oftw are . Many m ore th ings are s upporte d, lik e te xture s , re fractions , de pth of fie ld, caus tics , and e ve n proce dural s h ading. Ple as e vis it th e Sunflow h om e page (h ttp://s unflow .s ource forge .ne t) and th e Elys iun forum s (h ttp://w w w .e lys iun.com /) to le arn m ore . H appy re nde ring!

Ch ris toph e r Kulla is th e prim ary de ve lope r of th e Sunflow Re nde ring s ys te m . In h is day job h e w ork s as a s oftw are de ve lope r for Re e l FXCre ative Studios in Dallas , Te xas , w ork ing on com m e rcials , dire ct-to-DVD and anim ate d fe ature film proje cts .

h ttp://s unflow .s ource forge .ne t

19W O RK SH O P 3D - G I and H D RI ligh ting in Yafray

IntroductionTh e re are a m ultitude of w ays to ligh t a s ce ne , from a fe w s im ple s potligh ts , th rough are aligh ts and com ple x ligh t rigs upto diffe re nt form s of global illum ination. H e re I w ill be dis cus s ing th is latte r option us ing Yafray for re nde ring, from ins ide Ble nde r. Firs t I'd lik e to addre s s th e com m on m is conce ption th at GI is s om e m agic 'm ak e re alis tic re nde ring' button. It is s im ply a type of ligh ting m ode l th at is m ore advance d th an th e good old s pot lam ps , and m ore ph ys ically accurate . It w ill not autom atically m ak e a nice im age for you, it w ill s im ply give you a h e ad s tart by be ing a s ubs titution for a ve ry com ple x ligh ting rig w ith doz e ns of lam ps th at w ould ne e d to be place d

by h and. It th e re fore s ave s tim e (and tim e =m one y). It bas ically give s you a bas e fill ligh t, w ith an e ve n ligh t dis tribution, and a nice natural look . Th is can (and s h ould) be com ple m e nte d w ith traditional ligh ts .

Be s ide s th e ligh ting, th e GI re nde ring algorith m is als o re s pons ible for colour ble e ding be tw e e n obje cts (h ard to fak e w ith out GI), and caus tics (ne ar im pos s ible to fak e ). H ow e ve r, GI is s low e r th an raytracing and m uch s low e r th an s canline re nde ring, and is th e re fore only for final re nde ring for s tills . It can't re ally be us e d for anim ations (ye t), not only be caus e of re nde ring tim e , but be caus e ligh t/dark s pots are random ly re nde re d (s am ple d) and th e y jum p around from fram e to fram e .

Firs t w e 'll look at th e GI s e ttings for Yafray, and th e n I'll de s cribe a typical ligh ting s e tup th at I us e for product vis ualiz ation.

Global illum ination is diffe re nt from raytracing. In th e latte r a ray is trace d from th e cam e ra to an obje ct, th is can be re fle cte d/re fracte d, and th e n trace d to all ligh ts th at are vis ible . Th is give s you re fle ction, re fraction and (h ard) s h adow s . GI, on th e oth e r h and trace s th e path of th e ph otons th e m s e lve s from th e lam ps to th e obje cts , bouncing be tw e e n obje cts in th e s ce ne . Th is give s you re fle ction, re fraction AND colour ble e ding, s oft s h adow s , caus tics (im pos s ible w ith raytracing) and ge ne rally a nice r look . Th e origin of th e ligh t in GI can be a lam p, or any obje ct. For outs ide s ce ne s , th e w h ole back drop (w orld) can e m it ligh t. Since Ble nde r doe s not s upport GI ye t, I us e Yafray.

20W O RK SH O P 3D - G I and H D RI ligh ting in Yafray

GI s e ttingsFirs t, m ak e s ure th at you h ave Yafray ins talle d, and its location adde d to your OS's 'path ' variable (s e e th e Yafray re adm e !). In Ble nde r, go to th e re nde r buttons , and in th e drop-dow n lis t unde r th e large RENDER button, s e le ct Yafray. Th is s h ould ope n up tw o e xtra s e ttings pane ls : "Yafray" and "Yafray GI". In th e Yafray pane l, th e XML button s h ould be turne d off, th is allow s you to s e e th e re nde r in progre s s .

Th e tw o buttons be low allow you to s pe cify th e antialias ing. Oth e r buttons be low th e s e are n't im portant now , th e y don't ne e d to be ch ange d. Th e oth e r pane l, "Yafray GI" is m ore im portant. Th e "Me th od" drop-dow n lis t allow s you to s e le ct e ith e r None for no GI, Sk yDom e for a m e th od s im ilar to Ble nde r's Am bie nt Occlus ion, and Full for th e prope r global illum ination re nde ring. Se le cting Full w ill ope n up ne w buttons on th e bottom .

Th e Quality s e tting w ill de te rm ine th e (gue s s w h at!) q uality as w e ll as s pe e d of th e re nde r, a s e tting of m e dium /h igh s h ould be e nough for m os t s ituations . If th e re are s m all face s , de taile d m ode ls , or s urface s ve ry clos e to e ach oth e r, you m igh t ne e d to s e t th e q uality h igh e r to ge t rid of re nde r artifacts .

A com ple te GI s olution can be painfully s low to re nde r (h ours ), s o s om e trick s can be us e d to s pe e d it up. Turn on both th e Cach e and th e

Ph otons buttons in th e Yafray GI pane l. Th e ph oton cach e w ill s pe e d up th e re nde r ove r te n tim e s ! H ow e ve r, it w ill le ad to s om e brigh t/dark s pots on th e final re nde r. Incre as e th e Quality to ge t rid of th e s e , or ch ange th e "Re f" button. If you s e t th e "Re f" (re fine m e nt) to anyth ing oth e r th an 1 (I us e 0.1), it w ill calculate th e ph oton m ap tw o tim e s be fore th e final re nde r. Th e s e cond pas s doe s m ore calculations in th e parts of th e picture th at h ave m ore de tail, and th e final re s ult w ill th e re fore be be tte r.

Th e oth e r im portant s e ttings are : "Em itPw r" and "GI Pw r". Th e e m itpow e r de te rm ine s h ow brigh t e m itting obje cts , are aligh ts and th e back ground are . GI pow e r de te rm ine s h ow m uch "e ne rgy" (ligh t) th e s e e m itte rs w ill e m it. It is us ually e nough to ch ange th e GI Pow e r s e tting to m ak e your s ce ne dark e r or brigh te r.

Em itte rsTo us e GI, you ne e d to h ave s om e ligh t e m itte rs in your s ce ne . Ligh t e m itte rs in Ble nde r/Yafray can be th e follow ing: are aligh ts , obje cts w ith a m ate rial Em it value m ore th an 0, and th e back ground. Th e s im ple s t th ing to do is s e t th e back ground to any colour th at is n't black . Th e back ground

w ill e m it from all dire ctions e ve nly, s im ilar to an ove rcas t day outs ide . You can als o load a H DR ligh t probe , w h ich de te rm ine s w h at coloure d ligh t com e s from w h ich dire ction.

Now , le ts try s om e ligh ting! I w ill us e a s ce ne I did not too long ago, it is a de s ign for a fold-up w ine h olde r. You can s e e th e final im age h e re , it is for product vis ualiz ation. Th e re fore th e m os t im portant part of th e im age is th e product its e lf, and noth ing e ls e s h ould be pre s e nt to draw th e vie w e rs ' atte ntion aw ay, not e ve n a back ground s ce ne .

Product Vis ualiz ation I - "W h ite Space "

21W O RK SH O P 3D - G I and H D RI ligh ting in Yafray

Th is is one of m y favorite s e tups , for lack of a be tte r te rm I calle d it "w h ite s pace ", th e product is on a com ple te ly w h ite ground, w ith a w h ite back ground, ye t it doe s n't jus t float in s pace , it h as s h adow s . It look s ve ry good printe d on pape r, as w e ll as in any docum e nt or oth e r w h ite back ground (a w e bpage for e xam ple ), cre ating th e im pre s s ion th at th e obje ct its e lf is s itting th e re on th e pape r.

If you look clos e r, you can s e e th e re are tw o type s of s h adow h e re . Th e h ard s h adow com e s from a s un ligh t, but you can us e any oth e r type of ligh t th at cas ts s h adow s . NOTE: e xce pt are aligh ts ! Are aligh ts act as ph oton e m itte rs w h e n GI re nde ring in Yafray, and not as norm al ligh ts ! Th e nice s oft s h adow s are th e re s ult of GI.Th e s ce ne

Th e s ce ne , be s ide s th e product its e lf, is s im ply a w h ite plane , and a s un lam p, noth ing m ore , ve ry s im ple .

Th e ground.

Th e w h ite plane doe s n't e xte nd too far, jus t far e nough to catch all th e s h adow s of th e obje cts . It is com ple te ly w h ite , and th e Re fle ctivity is 1.0. Note th at th e option "Only s h adow " doe s n't w ork w ith Yafray. Th is m e ans th e e dge s of th e plane w ould be vis ible in th e final re nde r, w h ich is not good! Th is can be fixe d in th e re nde r s e ttings , s e e be low .

Th e ligh tTh e re is only one ligh t in th e s ce ne , a s un

lam p w ith Raytrace d s h adow s turne d on. It is s ligh tly ye llow is h in colour, w ith a pow e r of 0.6.

Th e W orld

Ve ry s im ple again, th e w orld is one coloure d, a ve ry s ligh tly blue is h w h ite .

Re nde r s e ttings

22W O RK SH O P 3D - G I and H D RI ligh ting in Yafray

IMPORTANT! It is re ally lam e , and I h ave s e e n bad e xam ple s of it m any tim e s , w h e n a product is s h ow cas e d on a gre y plane , floating in s pace , or at le as t on s om e s ort of back ground. Th is gre y plane s h outs CGI. It's im portant th at you can't s e e th is bas e plane , it s h ould ble nd into th e back ground. In th is e xam ple I us e d a w h ite plane , but e ve n a w h ite plane s om e tim e s is re nde re d gre y at th e e dge s . Th e back ground its e lf is s ligh tly blue and not w h ite . So th e trick to h ave th is "W h ite Space " e ffe ct is to s e t th e Em itPw r in th e Yafray GI s e ttings above 1.

It tak e s s om e e xpe rim e ntation for th e righ t s e ttings , s o th at you can't s e e th e e dge of th e bas e plane , but it doe s n't glow in an unnatural w ay e ith e r. A s e tting of 1.20 s e e m s to w ork w e ll. GI pow e r is 0.80. If you m ak e th e s un lam p brigh te r, th e n de cre as e th e s e s e ttings , if its dark e r th e n incre as e th e s e .

Mak e s om e low re s olution te s t re nde rs . Click and h old th e le ft m ous e button on th e re nde r, th is w ill s h ow th e colour of th e give n pixe l in th e bottom le ft corne r. Drag th e m ous e around, and m ak e s ure th at both th e back ground, and th e bas e plane is R: 255, G: 255, B: 255. Th e n you're re ady for th e h igh re s final re nde r! Mak e s ure to s e t th e q uality to Me dium or H igh , th e Re f value to s om e th ing oth e r th an 1, and turn on Antialias ing, in th is e xam ple I us e d 2 pas s e s w ith 4 s am ple s e ach , th is is th e s e tting I us ually us e , it is a good

q uality/s pe e d trade off. And s e e h ow m uch q uality w e h ave ach ie ve d w ith a ve ry s im ple s e tup!

Product Vis ualiz ation II - H DR Ligh tingIns te ad of a plain w h ite -is h w orld colour, you can s e t a H igh Dynam ic Range ligh t probe for th e back ground. Th is w ill vary th e ligh t colour

and inte ns ity acros s th e virtual s k y, m ak ing a m ore natural, s m ooth look . To clarify th e tw o te rm s , H DR m e ans h igh -dynam ic range im age , w h e re ins te ad of RGB value s from 0 to 255, floating point num be rs w ith be tte r pre cis ion, and a h igh e r "dynam ic range " are us e d to s tore th e lum inos ity (ligh t e m is s ion) of

e ach pixe l. Ligh t probe m e ans th e im age is a com ple te 360-de gre e panoram ic picture of th e e nvironm e nt. Th e proce s s of m ak ing H DR ligh t probe s is outs ide th e s cope of th is tutorial, s o I w ill jus t s ay e ith e r dow nload one of th e s e ve ral H DR probe s available on th e ne t (s e e h ttp://w w w .de be ve c.org for s om e s tarte rs ), or m ak e your ow n. Mak e s ure it is in th e ligh t probe form at (ak a. angular m ap), as oppos e d to: ve rtical cros s , latitude /longitude , or s om e oth e r panoram ic form at.

Th is ne xt s te p can be s k ippe d, but I h igh ly re com m e nd it. Th e proble m w ith GI illum ination w ith Yafray is th at for a a fas t re nde ring, it us e s s om e random s am ple s of th e e nvironm e nt. A nice and s h arp H DR im age can h ave diffe ring ligh t value s in a s h ort inte rval, ie : too m uch contras t. W ith jus t a fe w s am ple s , s om e s am ple s w ill fall onto a ve ry brigh t pixe l, and s om e w ill fall onto a ne arby dark e r pixe l, and th is w ill re s ult in a "s potty" re nde r. I s olve th is proble m by blurring th e original H DR m ap. From h ttp://w w w .h drs h op.org, you can dow nload H DRSh op v1 for fre e . Ope n your ligh t probe , and in th e Filte rs m e nu, s e le ct Gaus s ian blur, and blur th e im age , us ing a value of 4-5 for s m alle r m aps : 512*512, to 12-15 for h igh e r re s olution m aps , lik e 1512*1512. Re s ave it w ith a diffe re nt nam e .

23W O RK SH O P 3D - G I and H D RI ligh ting in Yafray

Loading th e H DR probeGo to th e te xture buttons , and s e le ct th e gre e n "W orld" button. Se t te xture type to Im age , and load th e *.h dr file lik e any oth e r im age . Go to th e w orld button, and in th e Map To pane l, s e t m apping to Angular m ap, and th e output to H ori, Z e nUp and Z e nDow n. Yafray w ill autom atically s e e th at you h ave a H DR w orld te xture , and w h e n GI is turne d on, it autom atically us e s th at im age for ligh ting.

Sce ne s e tupSim ilar to th e pre vious e xam ple . Th e bas e plane is not e nough h ow e ve r, as you w ill s e e its e dge in th e re nde r. To fix th is , m ak e th e farth e r e nd of th e plane curve up into th e air, h igh e nough to block all of th e cam e ra's file d of vie w . Mak e s ure th is curve s tarts farth e r th an th e s h adow s of th e obje ct, oth e rw is e you w ill s e e th e s h adow curve up unnaturally into th e air. Se e top righ t im age .

Ligh tsTh e "W h ite Space " m e th od above h ad a com ple te ly uniform w h ite ligh t, w h ich m e ans th e s un lam p us e d for th e additional h ard

s h adow could be place d anyw h e re . H ow e ve r, m os t H DR probe s h ave one or m ore conce ntrate d ligh t s ource s . Firs t re nde r th e s ce ne w ith only th e GI ligh ting and no lam ps . Se e w h ich w ay th e s oft s h adow s are cas t, and th e n pos ition th e s un lam p accordingly. You m igh t ne e d s e ve ral te s t re nde rs to ge t th e h ard s h adow pointing th e righ t w ay. I us ually us e ve ry s ubtle ,

w e ak ligh t(s ) w ith H DR m aps , th e e ne rgy s h ould be around 0.2-0.4, not m ore .

Re nde r s e ttingsTh e y s h ould be s im ilar to th e firs t m e th od, e xce pt for th e GI Pow e r s e tting. Th is can vary a lot w ith th e give n H DR m ap you are us ing,

de pe nding on h ow brigh t it is . Do s om e low re s q uick re nde rs to find th e righ t brigh tne s s . Som e dark e r m aps ne e d 1-1.5 at th e m os t, w h ile th e brigh te r one s m igh t only ne e d a GI Pow e r of 0.2. And th e n com e s th e final re nde r! H e re is m y te s t s ce ne w ith a s uns e t H DR probe m ade w ith Te rrage n. Th is s am e q uality w ith out GI w ould ne e d a fe w doz e n lam ps , all s e t up prope rly, s o w e cle arly s e e th e advantage s .

Not only do H DR m aps provide th e bas e ligh ting of a s ce ne , but th e y als o provide a re alis tic e nvironm e nt th e obje cts can re fle ct. Th e y can als o be th e back ground, h ow e ve r

m os t H DR probe s are too low -re s to provide a nice back ground im age . Ins te ad, it is pre fe rable to us e a ph oto of th e original location for a back ground. Th is te s t im age s h ow s one of m y ow n probe s in action, along w ith a ph oto back ground tak e n at th e s am e location. Note th at ins te ad of a gre y plane w h ich s cre am s CGI, I us e d a s tone pe de s tal, m ak ing it ble nd in be tte r.

24W O RK SH O P 3D - G I and H D RI ligh ting in Yafray

Th is w as jus t one s m all portion of w h at you can do w ith global illum ination, you can als o us e it for indoor s ce ne s . Try placing e m itting plane s or are a lam ps in your s ce ne . For caus tics , add "ph oton lam ps ", w h ich are available in th e Lam p s e ttings in Ble nde r.

Expe rim e nt. H ave fun!

I live in H ungary, and am curre ntly s tudying indus trial de s ign e ngine e ring at th e Budape s t Unive rs ity of Te ch nology and Econom ics .

Som e of m y h obbie s are : 3D graph ics of cours e :), conce pt de s ign/product de s ign, plus w atch ing good m ovie s , going out w ith frie nds , h anging out on e lys iun and oth e r forum s , draw ing.

h ttp://yafray.org

25W O RK SH O P 3D - Yafray caus tics s am ple r tutorial

In th is tutorial w e are going to e xpe rim e nt w ith Yafray and Ble nde r and le arn h ow th e y inte ract toge th e r. W e w ill cre ate a s im ple caus tic e ffe ct us ing de fault s e ttings . Furth e r e xpe rim e ntation can be us e d to cre ate bre ath tak ing im age ry!

Ge tting Starte dFirs t, w e w ill ne e d to h ave th e late s t ve rs ions of Ble nde r [Ble nde r 2.41] and Yafray [Yafray 0.7] both ins talle d on your com pute r. You can ge t th e s e from w w w .ble nde r.org and w w w .yafray.org re s pe ctive ly. Once

ins talle d, you w ill be re ady to be gin re nde ring your Firs t Caus tics s ce ne !

Us ing Caus tics Th e s e tup of th e s ce ne is ve ry s im ple . W e w ill be us ing th e de fault s ce ne w ith s om e lam p place m e nt ch ange s .

Ste p1. Launch Ble nde r.Ste p2. Go to th e Re nde r Buttons [F10] and s w itch th e Re nde re r from Ble nde r Inte rnal to th e Yafray Re nde re r.

Th is w ill cre ate s om e ne w pane ls in th e Re nde r Buttons , Edit Buttons , Mate rial Buttons , and th e Lam p Buttons . W e w ill ge t to th e s e ne w pane ls s h ortly.

Ste p3. In th e 3D W indow Se le ct [RMB] th e de fault cube . Go to th e Mate rial Buttons [F8]. Th e Raytracing Pane l introduce s th e available

Yafray fe ature s . W e w ill be m ak ing a cle ar glas s us ing de fault s e ttings for glas s in m ate rial pane l. Se le ct 'Cle ar Glas s ' from th e drop dow n m e nu. Se t th e re m ainde r of your m ate rial s e ttings to Fig. 1. You m igh t w ant to be ve l th e e dge s of th e m e s h . For th is obje ct I us e d Subdivide Multi 3X and th e n adde d a 0.100 Be ve l 2X and th e n applie d Se t Sm ooth . A bas ic be ve l w ould w ork jus t as w e ll. W atch th e im age at bottom .

Ste p4. In th e 3D W indow s w itch to Top Vie w [Num 7] and Add [Space Bar] a Plane [Add>>Me s h >>Plane ] to th e s ce ne , th is is going to be th e floor in th e s ce ne .. Exit Edit Mode [Tab]. You w ill ne e d to Move [G] it dow n along th e Z -axis [Z ] one grid unit [H old Ctrl] s o th at it is flus h w ith bottom of th e Cube . Ope n th e Trans form Prope rtie s Pane l [Nk e y] and s cale th e Plane to 50 units or s im ply pre s s [S] and s cale it to s pre ad up to th e cam e ra vie w . Go to th e Mate rial Buttons [F8] and Add a Ne w Mate rial.

26W O RK SH O P 3D - Yafray caus tics s am ple r tutorial

Mak e s ure to h ave th e Trace Sh adow fe ature e nable d in th is m ate rial. You can e ve n apply a te xture if you lik e . I us e d a ligh t blue s olid color for th is m ate rial.

Ste p5. In th e 3D w indow s w itch to Top Vie w [Num 7] and s e le ct [RMB] th e de fault lam p and de le te [De l] it. Now place your 3D Curs or at approxim ate ly 0,4,2 XYZ Global coordinate s . Pre s s [Space Bar] to add an Are a Lam p Add>>Lam p>>Are a. Th e lam p s h ould be autom atically s e le cte d, but if not s e le ct it and th e n bring up th e Trans form Prope rtie s Pane l

[N]. Se t th e Location XYZ coordinate s to 0,4,2 re s pe ctfully in th e trans form pane l. Se t th e Rotation XYZ coordinate s to 65,0,180 re s pe ctfully. In th e Mate rial/Lam p Buttons s e t th e pow e r to 0.250. Give it th e s h ape of a Sq uare 3.0. Se t th e 'Sh adow Sam ple s ' at 10 or gre ate r.

Ste p6. Duplicate [Sh ift+ D] th e Are a Ligh t th e n Cance l [RMB] th e Auto-Grab function. Th is w ill place th e duplicate d are a ligh t at th e e xact location of th e original are a ligh t. In th e Mate rial/Lam p buttons ch ange th e lam p type

to Ph oton Lam p. In Ble nde r only w ay to ge ne rate s caus tics in th e s ce ne is us ing th is lam p. Ch ange th e Ph oton s e ttings as in Fig. 2.

Ste p7. Now s w itch ove r to Re nde r Buttons [F10] and ch ange th e s e s e ttings as in Fig. 3.

Ste p8. Re nde r [F12] th e s ce ne ! Your re s ults s h ould be s im ilar to firs t im age in pre vious page . If your re nde r doe s n't m atch it try to m atch clos e ly th e s e ttings as give n e arlie r in th e figure s . You can als o look at th e e xam ple caus tics .ble nd file if you can't figure it out!

27W O RK SH O P 3D - Yafray caus tics s am ple r tutorial

W h at Jus t H appe ne d?Now th at w e h ave ge ne rate d a good e xam ple of Caus tics , now w e are going to look at h ow th e Caus tics w ork e d in th is s ce ne and w h at e ls e options are available in th e ble nde r inte rface . Th e re are th re e pane ls in ble nde r inte rface th at contain s e ttings for Caus tics :

Th e firs t one is th e Yafray Pane l its e lf. Th is pane l allow s you to control th e Yafray Re nde re r s e ttings . Norm ally it's good e nough to jus t dis able XML s o th at you can s e e th e inte ractive re nde ring. Als o you can le ave Auto-AA e nable d to le t Yafray autom atically control th e anti alias ing option. For de taile d control of Caus tics you w ill h ave to s w itch to m anual anti alias ing s e tting th ough .

Th e s e cond pane l is th e Yafray GI Pane l. GI s tands for Global Illum ination. Global Illum ination is th e e ffe ct produce d by th e ligh t be ing e m itte d from a Global ligh t s ource . For th is e xpe rim e nt w e us e d th e Full Type GI and s e t th e q uality to H igh for be tte r re s ults . Oth e r s e ttings are De pth and CDe pth . De pth is th e dis tance th at Yafray calculate s a s ingle ray during raytracing. Th e s m alle r th e value th e q uick e r but le s s accurate th e raytracing w ill be . CDe pth is s im ilar but it is for caus tics ph otons in th e s ce ne . Again th e s m alle r th e value th e q uick e r but le s s accurate th e caus tics in th e s ce ne w ill be . W e als o e nable d Ph otons in th is pane l. Th is w ill e nable GI Ph otons w h ich are als o re fe rre d to as H e lpe r

Ph otons . Th e y th e n are e m itte d from all of th e ligh ts in th e s ce ne . Th e m ore ph otons (w e us e d 100,000) be tte r th e re s ults , but th is w ill als o e xpone ntially incre as e th e re nde ring tim e .

Th e las t pane l is th e Lam p Pane l[F5]. Th is is locate d in th e Mate rial/Lam p buttons . You w ill ne e d to s e le ct th e ph oton lam p in th e s ce ne to s e e th e Yafray Sh adow and Ph oton tab. By e nabling Ph oton Lam p w e e nable th e us e of ph otons for th e caus tics from a dire ct s ource . H e re th e Pow e r s e tting is lik e any oth e r ligh t and te lls h ow "brigh t" th e caus tics w ill be . Th is ph oton lam p allow s us to dire ct th e dire ction of caus tic and optim iz e th e caus tics re s ults nice ly. W e us e d about 100,000 ph otons h e re . For s om e com ple x s ce ne it can go all th e w ay up to a m illion! It jus t de pe nds on h ow m uch com putation you w ant to do! You can e xpe rim e nt w ith th e oth e r s e ttings as th e y us ually re q uire s om e te s ting but de fault s e ttings w ill us ually ach ie ve good re s ults re gardle s s .

Exte nding Caus ticsCaus tics are not re s tricte d to Trans pare nt m ate rials e ith e r! You can us e caus tics for m e tallic m ate rials too, jus t re m e m be r th at tw o m e tallic m ate rials w ill als o re fle ct th e ph otons s o th e y ge ne rally w ill not s h ow up s om e tim e s .

To finis h up th is tutorial I'll give you s om e s ugge s tions to play around w ith :

Try adding a te xture or a color to th e Cube and giving it s om e Nor or Dis place m e nt.

Re place th e Cube w ith a Sph e re or anoth e r m e s h . Us e s e ve ral Ph oton Lam ps . H ave your s upe r clus te r h andy! Us e an H DR Global Te xture .

Em ail m e your e xpe rim e nts ! I'd love to tak e a look at th e m !

I am a 17 ye ar old graph ics artis t and program m e r from San Antonio, Te xas .

A fre e lance s tudio artis t at ID Studios [w w w .inte llide s ign.org]and a w e b program m e r at Mons te rW e b w w w .m ons te rw e b.ne t

28W O RK SH O P 2D - D PI de m y s tifie d

DPI de m ys tifie dYou did it! You h ave truly cre ate d a m as te rpie ce . But w h e n you printe d it out, it look e d all pixilate d and block y. Dang, you m us t h ave a bad s e tting s om e w h e re . You go back , double ch e ck all your s e ttings , h it re nde r again and w ait. It s till look s th e s am e w h e n you print it. You s tart glaring s ile nt th re ats at your printe r. W e ll, be fore you de cide to m ak e good on th os e th re ats , you m igh t w ant to try one m ore th ing (your printe r w ill th ank you for it).

You m ay h ave ove rlook e d th e w h ole DPI is s ue . W h ile it’s true th at Ble nde r h as s om e nice pre s e t re nde r s iz e s , if you don’t unde rs tand h ow th at re late s to printing, you w ill be fore ve r glaring at your printe r.

Firs t le t’s look at w h at DPI actually is .DPI is a printing te rm th at de s cribe s th e num be r of dots /pixe ls th at are de fine d in th e boundary of a s q uare inch th at are us e d to cre ate an im age . Th e m ore corre ct te rm is pixe ls pe r inch , h ow e ve r dots pe r inch is ofte n us e d ins te ad (Th e im age can be a font or graph ic). In ge ne ral, th e m ore dots , th e be tte r and s h arpe r th e im age . DPI is printe r re s olution. DPI is not im age re s olution alth ough fre q ue ntly us e d th at w ay.Ok , now th at w e k now w h at DPI is , le t’s look at h ow it applie s to Ble nde r. Ble nde r re nde rs im age s out at 72dpi, w h ich look s ok ay on your

s cre e n, but not printe d out. In orde r for it to look good for print, you h ave to re nde r your im age bigge r and th e n re s iz e it s m alle r in your favorite graph ic program . Es s e ntially w h at you w ill be doing is s w apping ph ys ical dim e ns ions for re s olution. Tak e a look at th e follow ing ch art (fig. 1 be low ). It s h ow s s om e com m on re nde r s iz e s in pixe ls and th e corre s ponding ph ys ical s iz e s at 72dpi (w h ich Ble nde r us e s ) and a good print re s olution of 300dpi. You can s e e th at th e ph ys ical s iz e s be com e s m alle r as you incre as e th e re s olution.

Th is m ay s e e m ove rly com plicate d, but re ally it is not. Th e re is a ve ry s im ple form ula you can us e to ge t th e prope r s e ttings . Bas ically you m ultiply th e de s ire d re s olution by th e de s ire d ph ys ical s iz e to ge t th e pixe l s e ttings /s iz e you ne e d for Ble nde r (fig. 2).

Once you h ave re nde re d your im age us ing th os e s e ttings , you ne e d to go into your favorite im age program and re s iz e your im age . Mos t im age program s w ork s im ilarly, s o figuring it out in your program s h ouldn’t be difficult. I w ill be us ing Ph otos h op to e xplain th is part, be caus e th at is w h at I h ave .

29W O RK SH O P 2D - D PI de m y s tifie d

Ste p 1: Ope n your im age

Ste p 2: Go to Im age >Im age Siz e , a dialog box lik e fig. 3 s h ould ope n.

Ste p 3: At th e bottom of th e box, unch e ck “Re s am ple Im age ”

Ste p 4: Ne xt locate th e “Re s olution Box”, e nte r your ne w re s olution. Th e W idth and H e igh t boxe s s h ould autom atically update to re fle ct th e ne w s iz e at th at re s olution.

Ste p 5: H it th e “OK” button and s ave , you are all done and now your im age w ill print lik e you e xpe cte d it to.

Ok ay, s o now you h ave a be tte r unde rs tanding of dpi and h ow to ge t th e prope r dpi for printing, but w h at dpi re s olution is be s t for w h at you ne e d. As a ge ne ral rule , you s h ould ch oos e a re s olution be tw e e n 150-300 dpi. Th is re s olution is good for m os t print proje cts . If you are h aving s om e th ing profe s s ionally printe d, it is alw ays a good ide a to ch e ck w ith your printe r and find out w h at re s olution th e ir e q uipm e nt runs at.

H i, m y nam e is Sandra Gilbe rt, (ak a dre am s gate ). I h ave be e n us ing ble nde r for a little ove r five ye ars . I curre ntly live in Nam pa, Idah o, USA and w ork as a graph ic de s igne r for a s m all print s h op.

I’m m arrie d and h ave 2 ch ildre n, w h ich le ave s not ne ar e nough tim e for fe e ding m y grow ing ble nde r obs e s s ion. Ye t s om e h ow I alw ays m anage to find th e tim e to e xplore ne w fe ature s , k e e p up on th e late s t ne w s and s tart ne w ble nde r proje cts . Som e of th e m I actually e ve n m anage to finis h .

30Unde r re vie w

Book Re vie wDigital Ligh ting and Re nde ring

Th is is s ue w e are re vie w ing “[digital] Ligh ting and Re nde ring” by Je re m y Birn.

By now w e h ave all figure d out, or s oon w ill, th at ligh ting is a ve ry large part of any s ucce s s ful proje ct. You can h ave th e be s t m ode ls , m ate rials and com pos ition, but w ith out prope r ligh ting your im age w ill fall flat.

Ente r “[digital] Ligh ting and Re nde ring”. Je re m y Birn tak e s you s te p by s te p, w ith logical and cle arly e xplaine d e xam ple s , th rough th e ofte n com ple x and confus ing are a of ligh ting. H e s tarts you off w ith h ow to s e t up a good ligh t w ork flow and th e n e xplains e ach type of ligh t you s h ould h ave available .

H e continue s w ith in-de pth dis cus s ions on w h at ligh ting is and h ow ligh t and s h adow be h ave in th e re al w orld, th e n progre s s e s th rough color th e ory, q uality of ligh t and s h adow and e xpos ure .

No book on ligh ting w ould be any good w ith out a th orough dis cus s ion of ligh t s e tups . And th is one is an e xce lle nt re s ource for le arning about th e various ligh t s e tups and th e ir us e s .H e goe s on to e xplain h ow m ate rials fit into th e re nde ring pipe line . Starting w ith s h ading s urface s , h e w ork s h is w ay th rough de taile d e xplanations of h ow diffe re nt m ate rial s e tups

affe ct ligh ting and re nde ring. In th is s am e ch apte r h e als o e xplains th e us e s and advantage s of raytracing and global illum ination.

Th e final ch apte r cove rs com pos iting and re nde ring in laye rs , s h ow ing th e us e of diffe re nt re nde r pas s e s to ge t jus t th e e ffe ct you are look ing for.

Th is book is a de finite “m us t re ad” for be ginne rs and ye t e ve n an e xpe rie nce d CG artis t w ill find it w orth a look .

--ble nde rart

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44Ends cape

H e llo! de ar ble nde r h e ads .

W e h ave be e n bringing forth a bundle of good le arning m ate rial for you for th e pas t s ix m onth s . In e ve ry is s ue , w e tak e on a particular as pe ct of CG re late d to Ble nde r and pre s e nt you w ith a pack of us e ful le arning m ate rial. All th is is m anage d w ith th e h e lp of th e e xpe rie nce d ble nde r h e ads from w ith in th e ble nde r com m unity. Th e y h e lp s pre ad th e k now le dge by s h aring conte nt from th e ir re s pe ctive fie ld of e xpe rtis e .

Back w h e n w e jus t s tarte d th e m agaz ine , it w as our aim to provide a good re s ource to cove r th e diffe re nt as pe cts of CG w ith th e m ain focus be ing on th e e as e of le arning for th e ne w us e rs . W e h ave be e n ove rw h e lm e d by th e cons tant apprais al and fe e dback w e got from th e ble nde r com m unity. Th at s h ow s th at w e h ave at le as t be e n s ucce s s ful in th at are a. I tak e th is opportunity on be h alf of our s m all te am at ble nde rart to th ank you all for your com m e nts and fe e dback and at tim e s , patie nce . And als o to th e folk s w h o h ave provide d m uch ne e de d m ate rial for th e m agaz ine .

Th is tim e w e got our w e bs ite h os te d th ank s to ibiblio.org w h ich gracious ly provide d us w ith th e w e b s pace . Nam Ph am did a gre at job w ith th e ne w w e bs ite de s ign and h e h as als o provide d th e long w ante d s olution for s ubs cribing to our m ailing lis t. Now all th os e w h o w ill s ubs cribe to it w ill ge t notifie d as s oon as th e ne w is s ue is launch e d.

W ith th is is s ue out w e are als o s tarting to re s tructure both th e m agaz ine de s ign and th e conte nts s o th at w e can continue to provide you all w ith e ve n be tte r le arning e xpe rie nce for th e tim e to com e .

So until th e n do k e e p s e nding us your valuable fe e dback and com m e nts .

H appy ble nding!Gauravgaurav@ ble nde rart.org

45D is claim e r