Rendering With AutoCAD Using NXtRender

(1)

(2)

(3)

-Table of Contents

Chapter 1 - Getting Started 1.1 - R e nde ring O ve rvie w 1.2 - Downloa d a nd Insta lla tion 1.3 - Lice nsing

Chapter 2 - Tutorials and Videos 2.1 - R e nde ring with AutoC AD 2.2 - Insta lla tion Vide o 2.3 - Lighting Ba sics Tutoria l 2.4 - Inte rior Lights Tutoria l

2.5 - nXtR e nde r Ba sic Ma te ria ls Tutoria l 2.6 - Multipa ss re nde ring Vide o

Chapter 3 - The Basics 3.1 - R e nde ring 3.2 - Tone Ma pping 3.3 - C olor Ma ps

3.4 - Adding a nd a ssigning m a te ria ls 3.5 - Lighting

3.6 - Adding lights 3.7 - W ork ing with Pla nts Chapter 4 - Beyond the Basics 4.1 - W ork ing with te x ture s 4.2 - W ork ing with de ca ls

4.3 - W ork ing with R e fle ction Sha de rs

4.4 - Adding indire ct lighting to a n e x te rior re nde ring

4.5 - C om bining da ylighting a nd a rtificia l lighting for a n inte rior re nde ring 4.6 - W ork ing with HDR Is

4.7 - Lighting C ha nne ls

4.8 - Using IES (photom e tric) lights 4.9 - R e nde ring Engine s

4.10 - C ontrolling te sse la tion-- sm oothing curve d obje cts 4.11 - Using Archvision R PC with nXtR e nde r

4.12 - Using Te x ture d Me sh File s (3DS or O BJ) with nXtR e nde r Chapter 5 - Lighting Palette

5.1 - The Sun Ta b 5.2 - The Sk y Ta b 5.3 - The Lights Ta b 5.4 - The Ba ck grounds Ta b 5.5 - The Adva nce d Lighting ta b Chapter 6 - Materials Palette 6.1 - Ma te ria ls Ta b

6.2 - Adva nce d Ma te ria l Editor 6.3 - The Ma te ria l Tre e Chapter 7 - Other Palettes 7.1 - R e nde r Se ttings 7.2 - O bje ct Prope rtie s

7.3 - The Adva nce d O bje ct Prope rtie s Ta b Chapter 8 - Walkabout and Animation 8.1 - W a lk About

8.2 - 3D slide show a nim a tions Chapter 9 - nXtRender Add-ons 9.1 - Ba ck ground W iza rd 9.2 - La ye r Ma te ria l Sche m e s 9.3 - R e nde r R e a dy Block s

Chapter 10 - Other Advanced Topics 10.1 - Using Burn

10.2 - Im a ge Editor 10.3 - Ba tch re nde ring 10.4 - R e nde r Fa rm

10.5 - C onve rting Le ga cy AR 3/AR 4 Ma te ria l Libra rie s 10.6 - Using Le ga cy AR 3/AR 4 Pla nts

10.7 - Volum e tric Fog 10.8 - Sub-surfa ce Sca tte ring Chapter 11 - Troubleshooting

Title Page

(4)

11.1 - R e nde ring ha s som e bright spots or "spe ck le " a rtifa cts 11.2 - Ma te ria ls a ssigne d by la ye r a re not a ppe a ring in the re nde ring 11.3 - C ra sh occurs on 32-bit syste m (hi-re s or com ple x m ode l) Chapter 12 - Miscellaneous

12.1 - Te chnica l Spe cifica tions 12.2 - nXtR e nde r Pla tform s 12.3 - C onta ct Inform a tion Index

R e nde ring with AutoC AD using nXtR e nde r

(5)

-nXtRender Getting Started

Ge t sta rte d with a n ove rvie w of R e nde ring, Insta lla tion, Lice nsing a nd som e vide o tutoria ls.

Sa la 020612 by Jorge Ja vie r La ra Dom inque z

Chapter 1 - Getting Started

(6)

nXtRender Rendering Overview

nXtR e nde r cre a te s stunning life -lik e im a ge s from AutoC AD m ode ls. nXtR e nde r use s R a y Tra cing a nd photom e tric re nde ring te chnologie s from inside AutoC AD to cre a te high-qua lity photo-re a listic im a ge s from 3D Mode ls.

R e nde ring by Surya Mura li using nXt Engine

W ith nXtR e nde r, cre a ting pre se nta tion qua lity im a ge s from AutoC AD m ode ls is e a sy. Sim ply a dd m a te ria ls, lights, sun, sk y a nd the n re nde r the m ode l.

General Features

Ea sy to use , work s se a m le ssly inside AutoC AD, a nd provide s a host of fe a ture s tha t spe e d a nd sim plify im a ge re nde ring. Use s both ra ytra cing a nd Indire ct Lighting to cre a te sophistica te d single -fra m e im a ge s a nd a nim a tions.

Autom a tica lly ca lcula te s indire ct light, ha rd a nd soft sha dows, color ble e ding, re fle ctions, tra nsluce ncy, tra nspa re ncy, re fra ction, highlight, de pth of fie ld, a nd de pth a tte nua tion.

Supports m ultiproce ssors a nd ba ck ground proce ssing.

Include s m a the m a tica lly ge ne ra te d 3-D pla nts with se a sona l va ria tion, giving re a listic pla nts, sha dows, a nd re fle ctions. W ork s inside AutoC AD. R e nde r cha nge s to the m ode l im m e dia te ly. You ne ve r ne e d to e x port or sta rt ove r.

Progre ssive -re fine m e nt re nde ring a lgorithm s with on-scre e n pre vie w. Sa ve a nd re store pla nt, e x posure , sun a nd sk y, a nd e nvironm e nt se ttings. Gra phica l libra ry browse rs for m a te ria ls a nd pla nts.

R PC 3D O bje ct support.

Post-proce ssing for quick a djustm e nt of brightne ss, Lighting C ha nne ls, fog, gla re , a nd de pth of fie ld. R e nde ring with AutoC AD using nXtR e nde r

(7)

-nXtRender for AutoCAD - Installation

Download

nXtR e nde r ca n be downloa de d from :

http://nx tre nde r.com /downloa d/

Installation

Afte r downloa ding nXtR e nde r for AutoC AD, run the insta lla tion. W he n you ne x t sta rt AutoC AD, type in the com m a nd: nXt nXtRender Installation Video

W a tch Vide o

www.youtube .com /wa tch?v=BrU4H64AsEI

In this Vide o, Da nie l Ha rgre a ve s of AccuStudio will show you how to downloa d a nd insta ll nXtR e nde r for re nde ring your AutoC AD dra wings.

nXtRender for AutoC AD is the re nde ring e ngine tha t a llows you to e a sily cre a te stunning, life -lik e im a ge s from your 3D m ode ls inside AutoC AD a nd AutoC AD Archite cture . nXtR e nde r provide s the highe st qua lity in AutoC AD visua liza tion solution a va ila ble toda y.

Additiona l

FAQ

nXtRender does not load

I type nXt at the command prompt but nXtRender does not load. Instead AutoCAD produces the error message Unknown Command "nXt".

Norm a lly nXtR e nde r re giste rs its com m a nds with AutoC AD during insta lla tion. O n occa sion, this m e cha nism m a y fa il. In this ca se you will ne e d to m a nua lly loa d nXtR e nde r the first tim e you run it in a pa rticula r ve rsion of AutoC AD. Use the following proce dure :

1. Type _a pploa d a t the com m a nd line .

2. Na viga te to the folde r whe re nXtR e nde r wa s insta lle d. This is norm a lly C :\Progra m File s\AccuR e nde r nXt. 3. Se le ct one of the following file s de pe nding on your pla tform :

AccuR e nde r nXt.a rx -O R - AccuR e nde r nXt64.a rx (AutoC AD 2007 - 2009)

AccuR e nde r nXt_18_.a rx -O R - AccuR e nde r nXt_18_64.a rx (AutoC AD 2010 - 2012) AccuR e nde r nXt_19_.a rx -O R - AccuR e nde r nXt_19_64.a rx (AutoC AD 2013 - 2015)

4. Pre ss Loa d

C he ck the AutoC AD com m a nd line to ve rify tha t the a pplica tion loa de d without e rror. At this point you should be a ble to type nx t or a r5 to la unch the a pplica tion. You should not ha ve to re pe a t this proce dure a ga in for this ve rsion of AutoC AD. Sim ply typing nx t or a r5 a t the com m a nd prom pt should ca use nXtR e nde r to loa d. You m a y ne e d to re pe a t this proce dure if you

Download and Installation - 1.2

(8)

insta ll a nothe r ve rsion of AutoC AD. R e nde ring with AutoC AD using nXtR e nde r

(9)

-nXtRender for AutoCAD - Licensing

30 day free Trial

nXtR e nde r will run in full m ode (no wa te rm a rk s or lim ita tions) for 30 da ys. Afte r 30 da ys you will ne e d to purcha se a lice nse from :

http://nx tre nde r.com /purcha se /

Licensing

Sta rt AutoC AD a nd type in nXt

Use the se click to bring up the lice nse dia log:

Fill in the lice nsing inform a tion a nd click "C he ck Lice nse a nd Va lida te "

Licensing - 1.3

(10)

a nd fill out the form , e nte ring this lice nse code , com pa ny na m e e tc.

C lick C he ck Lice nse a nd Va lida te to obta in a n Authoriza tion C ode for your com pute r, for this a pplica tion.

If, for som e re a son, you ca nnot use Va lida te O nline to ge t your Auth C ode : click R e port Proble m to e m a il the va lida tion inform a tion to us, a nd we will se nd you a n Auth C ode by e m a il.

(If you ca nnot se nd e m a ils from this m a chine , you ca n click C opy, copy the inform a tion to the clipboa rd, pa ste it into a docum e nt, tra nsfe r it to a nothe r m a chine a nd e m a il it to us)

(11)

-nXtRender Tutorials and Videos

R e nde ring in AutoC AD

Insta lla tion Vide o

Lighting Ba sics Tutoria l

Inte rior Lights Tutoria l

Ba sic Ma te ria ls Tutoria l

Chapter 2 - Tutorials and Videos

(12)

Rendering with AutoCAD

nXtRender Installation Video

W a tch Vide o

In this vide o, Da nie l shows you how re nde r your 3D m ode l using AutoC AD a nd the n how to ge t e ve n be tte r re sults using a n inte gra te d a dd-on re nde re r nXtR e nde r.

nXtR e nde r (form a lly ca lle d AccuR e nde r nXt) m a k e s it e a sy to a dd lights, m a te ria ls, tre e s, ba ck grounds, e tc. to ge t a profe ssiona l re nde ring re sult quick ly from your AutoC AD m ode l.

Additiona l

(13)

-nXtRender Installation Video

nXtRender Installation Video

W a tch Vide o

In this Vide o, Da nie l Ha rgre a ve s of AccuStudio will show you how to downloa d a nd insta ll nXtR e nde r for re nde ring your AutoC AD dra wings.

nXtRender for AutoC AD is the re nde ring e ngine tha t a llows you to e a sily cre a te stunning, life -lik e im a ge s from your 3D m ode ls inside AutoC AD a nd AutoC AD Archite cture . nXtR e nde r provide s the highe st qua lity in AutoC AD visua liza tion solution a va ila ble toda y.

Additiona l

Installation Video - 2.2

(14)

nXtRender Lighting Basics Tutorial

This Lighting Ba sics Tutoria l will show you how to do ba sic lighting in nXtR e nde r.

Lighting Basics Video

Lighting Basics Video

W a tch Vide o

www.youtube .com /wa tch?v=A-u0z0XKn9k

In this Vide o, Da nie l Ha rgre a ve s of AccuStudio will show you how to use the lighting de fa ults to cre a te ba sic lighting conditions for nXtR e nde r while re nde ring your AutoC AD dra wings.

Lighting De fa ults m a k e it e a sy to se t the lighting pa ra m e te rs for inte rior sce ne s, e x te rior sce ne s, or to chose studio for re nde ring of individua l obje cts without ha ving to k now a lot a bout the de ta ils of lighting se ttings

Additiona l

Lighting Basics Tutorial

Step 1 - Download Model

Downloa d m ode l from : AccuStudio

Loa d the m ode l into AutoC AD a nd sta rt nXt

Step 2 - Add a Ground Plane

(15)

-Go to the W idge t icon a nd se le ct Groundpla ne . You'll be a ble to put a pla ne unde r your m ode l.

Step 3 - Render with Studio Lighting

C lick the double Down Arrow on the Lighting Ta b to e x pa nd the ta b.

The re a re 4 pre se t lighting choice s - Studio, Ex te rior, Da ylight a nd Inte rior Lighting - se le ct Studio.

C lick the gre e n ca r to sta rt the re nde ring. Le t it run for a bout 100 pa sse s.

Notice the subtle sha dows unde r the e a ve s a nd on the ground.

Lighting Basics Tutorial - 2.3

(16)

Step 4 - Change the lighting to exterior

This is a single source of light lik e the sun le ts you cha nge a zim uth a nd a ltitude . W e 're going to sta y with the de fa ult. C lick the gre e n ca r a nd le t the re nde ring run for a bout fifty pa sse s.

W e will e x plore the othe r two se ttings - Inte rior Da ylight a nd Inte rior Lighting - in a nothe r Tutoria l. The y work be st for inte rior sce ne s with inte rior lights.

Step 5 - Use Model colors

Now le t's e x plore cha nging the m ode l to use m ode l colors a nd studio lights

Go to the re nde r se tting, click on the double down a rrow, scroll to the bottom a nd put a che ck m a rk ne st to Use object color.

Go ba ck to lighting, m a k e sure studio lighting is se t, a nd click the gre e n ca r to be gin the re nde ring proce ss

Inste a d of a n a ll-white m ode l, nXtR e nde r ha s loa de d la ye r colors into the m ode l. It will ta k e m ore pa sse s to ge t a good re nde ring with colors.

Le t it run for a bout 200 pa sse s.

(17)

-Notice tha t the ba ck ground is in white . This is be ca use the m ode l colors re spond to the lighting.

Lighting Basics Tutorial - 2.3

(18)

nXtRender Interior Lights Tutorial

This Tutoria l will show you show you how to use the lighting de fa ults to cre a te ba sic lighting conditions for nXtR e nde r while re nde ring your AutoC AD dra wings.

Lighting De fa ults m a k e it e a sy to se t the lighting pa ra m e te rs for inte rior sce ne s, e x te rior sce ne s, or to chose studio for re nde ring of individua l obje cts without ha ving to k now a lot a bout the de ta ils of lighting se ttings.

Interior Lights Video

W a tch Vide o

www.youtube .com /wa tch?v=e fA5Z-sPGpg

In this Vide o, Da nie l will show you how to conve rt e x isting ge om e try in your m ode l to lights, a nd to pla ce ne w la m ps into your m ode l using nXtR e nde r for AutoC AD.

Additiona l

Interior Lights Tutorial

Download Model

Downloa d m ode l from : AccuStudio

Loa d the m ode l into AutoC AD a nd sta rt nXt

Isolate Light Fixtures

C ha nge your vie w, a nd turn off othe r la ye rs to isola te the light obje cts.

This will m a k e se le cting the lights m uch e a sie r. R e nde ring with AutoC AD using nXtR e nde r

(19)

-Select and Name Light Objects

The re a re two m e thods for cre a ting lights. O ne is to cre a te a light source a nd pla ce it in the m ode l. The othe r is to se le ct a n e x isting obje ct a nd give it light prope rtie s.

First, se le ct a n e x isting obje ct a nd give it a na m e in this ca se ce iling light.

C ontinue pick ing the lights a nd giving the m na m e s Mark Objects as Lights

O nce the y a re a ll se le cte d a nd na m e d you ca n cha nge the obje cts into lights by highlighting the m , right click ing, a nd se le cting Prope rtie s.

Interior Lights Tutorial - 2.4

(20)

You ca n se t the wa tta ge , or othe r prope rtie s a s de sire d.

Render Scene with Lights Turn a ll of your la ye rs ba ck on.

Se le ct the Inte rior Lighting De fa ult, a nd the n click on the gre e n ca r to be gin the re nde ring. A good re nde ring with lights ca n ta k e m a ny pa sse s to com ple te .

(21)

-Interior Lights Tutorial - 2.4

(22)

nXtRender Basic Materials Tutorial

This tutoria l will show you how to cre a te m a te ria ls a nd use m a te ria ls from libra rie s using nXtR e nde r for AutoC AD. (form e rly AccuR e nde r nXt)

C re a te a solid color m a te ria l, cre a te a m a te ria l with a te x ture , se le ct a nd pla ce m a te ria ls from libra rie s. Creating and using Materials Video

W a tch Vide o

www.youtube .com /wa tch?v=q0Dnl5Pnog4

In this Vide o, Da nie l will show you how to cre a te m a te ria ls a nd use m a te ria ls from libra rie s using nXtR e nde r for AutoC AD. C re a te a solid color m a te ria l, cre a te a m a te ria l with a te x ture , se le ct a nd pla ce m a te ria ls from libra rie s.

Additiona l

Basic Materials Tutorial

Download Model

You ca n downloa d sa m ple m ode ls for this vide o from a ccustudio.com /work shop/m ode ls

Loa d the m ode l into AutoC AD a nd la unch nXtR e nde r (type nXt) Materials Tab

C lick the double down a rrow for m a te ria ls a nd you'll se e the re 's a sm a ll toolba r. W e 're going to focus on the first fe w icons. You ca n e ithe r cre a te a ne w m a te ria l, or loa d one from a n e x isting source .

Create New Material

C lick the down a rrow ne x t to little purple sphe re the re se ve ra l m a te ria l choice s. Sta rt with solid color.

(23)

-This brings up the ba sic m a te ria l dia log box

C lick on the gra y or colore d squa re . This brings up the color whe e l.

nXtRender Basic Materials Tutorial - 2.5

(24)

C lick in the color box you'll se e tha t the m a te ria l cha nge s in re a l tim e . So you ha ve a ge ne ra l ide a with a look lik e in your m ode l.

Create a Textured Material

C lick on the te x ture d icon it brings up a dia log box e s se le ct a bitm a p.

Se t the Sca le of the bitm a p.

(25)

-The sca le should re fle ct the re a l world size tha t you ne e d for your bitm a p. Set as Bump Map

C lick the Adva nce d button to loa d the Adva nce d Ma te ria l Editor. C lick the Te x ture Ta b.

Se t the Bum p Ma p va lue to 2.5.

This will incre a se the 3D e ffe ct of the te x ture d m a te ria l. Use Saved or Library Material

(26)

C lick the Open icon to se le ct a m a te rie l from the disk .

You ca n downloa d pre -m a de m a te ria ls from nXtR e nde r:

www.a ccure nde r.com /pa ge /m a te ria l-libra rie s

or from AccuStudio.

[www.a ccustudio.com /e x cha nge /m a te ria ls

Downloa d som e m a te ria ls, a nd se le ct one from the disk . The re a re two wa ys to pla ce m a te ria ls with nXtR e nde r. Drag and Drop a Material

Dra g a m a te ria l from the m a te ria l browse r to a n obje ct in AutoC AD. R e nde ring with AutoC AD using nXtR e nde r

(27)

-Hove r ove r the obje ct a nd choose pla ce m e nt by la ye r or by obje ct.

Pla ce m e nt by la ye r will a ssign the m a te ria l to a ll obje cts tha t a re on the la ye r.

Render Model

Afte r you finish a ssigning the m a te ria ls, re nde r a vie w of te m ode l.

Le t it run for a bout fifte e n pa sse s with da ylight pre se ts. If you ha ppy with the m a te ria ls,the n re nde r a ny vie w you lik e .

(28)

Multipass rendering Video

Mutli Pass Rendering Technology Video

W a tch Vide o

www.youtube .com /wa tch?v=3o1oJv5l9Do

This vide o, ta k e n from a W e bina r for the nXtR e nde r/IR e nde r/AccuR e nde r nXt Engine e x pla ins som e of the a dva nta ge s of m ulti-pa ss re nde ring.

Multi Pa ss re nde ring le ts you quick ly se e wha t your re nde ring is going to look lik e – a fte r the first fe w pa sse s – a nd the e ithe r cha nge se ttings, or le t the re nde ring continue go ge t be tte r.

In this vide o Scott Da vidson shows you how m ulti-pa ss re nde ring work s for nXtR e nde r for AutoC AD, R e vit or Sk e tchUp. R e nde ring with AutoC AD using nXtR e nde r

(29)

-nXtRender The Basics

Ge t Sta rte d with re nde ring, lights a nd m a te ria ls.

Apa rta m e nto e n Los Na ra njos by Ale ja ndro Te sta

Chapter 3 - The Basics

(30)

Rendering

Starting and Stopping a Rendering

C lick the R e nde r AutoC AD Vie wport button on the pa le tte to initia te a re nde ring of the curre nt AutoC AD vie wport:

By de fa ult, the re nde ring proce ss will continue re fining the im a ge , pa ss by pa ss, until you te ll it to stop by pre ssing the Stop R e nde ring button. This a llows you to m a na ge the tra de -off be twe e n tim e a nd qua lity. The longe r you a llow the re nde ring to continue , the m ore close ly it will re se m ble its fully-conve rge d or "corre ct" re sult. You ca n stop a re nde ring a fte r se conds, m inute s, hours or da ys. It's e ntire ly up to you.

Pre ssing the Pa use R e nde ring button once will suspe nd the re nde ring a fte r the curre nt pa ss is com ple te d. Pre ssing the sa m e button a ga in will ca use the re nde ring to te rm ina te a s soon a s possible . A suspe nde d re nde ring ca n pick up whe re it le ft off by using the C ontinue button. Pre ssing the C lose button on the window fra m e im m e dia te ly te rm ina te s the re nde ring a nd close s the displa y.

You ca n continue to work in AutoC AD while a re nde ring is a ctive , by pre ssing the Minim ize button on the nXtR e nde r displa y. The displa y ca n be re store d a t a ny tim e by pre ssing the Show C urre nt R e nde ring button, or by using the W indows Ta sk ba r.

Additional Notes

nXtR e nde r produce s im a ge s by using re a l world lum ina nce va lue s. The proce ss of conve rting lum ina nce va lue s to displa ya ble pix e ls is ca lle d Tone Ma pping .

He re a re som e sugge ste d num be r of pa sse s for a sa tisfa ctory re sult unde r a fe w diffe re nt sce na rios (your a ctua l re sults m a y va ry):

De fa ult e x te rior sce ne s, 10-15 pa sse s Ex te riors with indire ct lighting, 25-50 pa sse s

Inte rior a rtificia l light sim ula tions, 25 pa sse s pe r se t of 8 lights Inte rior da ylight sim ula tions, 50-100 pa sse s

Studio m ode ls, 10-15 pa sse s

If you do not wa nt your re nde ring to continue inde finite ly, you ca n use the Pa sse s se tting on the R e nde r Se ttings ta b to se t a n a utom a tic stopping point. A Pa sse s se tting of 0, the de fa ult, m e a ns continue inde finite ly until m a nua l te rrm ina tion.

An Autosa ve option is provide d in the R e nde r Se ttings ta b to force nXtR e nde r to sa ve your re nde ring pe riodica lly. This m a y re sult in usa ble work e ve n a fte r a powe r outa ge ha s inte rrupte d the proce ss. Se e Sa ving your R e nde ring, be low. The sta tus ba r a t the bottom of the nXtR e nde r displa y shows m ouse -ove r inform a tion a bout e a ch pix e l in the re nde ring, including the R GB va lue (lum ina nce ) a nd the re sulting color a fte r tone -m a pping.

Rendering Resolution

Se t the re nde ring re solution in the R e nde r Se ttings ta b of the nXtR e nde r pa le tte . The Tota l Pix e ls option is a n e a sy wa y to m a tch the AutoC AD vie wport e x a ctly. The de fa ult se tting of 300,000 pix e ls provide s a good se tting for doing proofs or im a ge s de stine d for the we b. 3,000,000 pix e ls or m ore m a y be re quire d for a fina l, printe d, im a ge .

Proce ssing tim e a nd m e m ory usa ge a re dire ctly (line a rly) re la te d to the tota l num be r of pix e ls in your re nde ring. The highe r the re solution, the longe r the re nde ring will ta k e a nd the m ore m e m ory it will re quire .

Saving Your Rendering

The Sa ve R e nde ring button a llows you to sa ve your re nde ring to se ve ra l diffe re nt im a ge form a ts. You ca n sa ve to m ost form a ts while a re nde ring is in progre ss.

The Alpha cha nne l ve rsions of the file form a ts a re m e a nt to be use d for high-qua lity com positing. Ba ck grounds will a ppe a r R e nde ring with AutoC AD using nXtR e nde r

(31)

-bla ck whe n the re nde ring is sa ve d with Alpha cha nne l.

The .hdr a nd .e x r form a ts store lum ina nce da ta dire ctly in a High Dyna m ic R a nge form a t. Non-lum ina nce ba ck grounds, such a s norm a l photogra phs, will a ppe a r bla ck whe n sa ve d in one of the se form a ts.

The .nXtIm a ge form a t is the na tive im a ge form a t of the nXtR e nde r re nde ring. It is the re com m e nde d form a t for storing your re nde rings, since it pre se rve s the m ost inform a tion a bout your re nde ring. Im a ge s store d in this form a t ca n be m a nipula te d in the nXt Im a ge Editor a nd spe cia l FX ca n be a dde d. From this e ditor, you ca n sa ve to m a ny popula r sta nda rd form a ts,

including a ll of the form a ts supporte d in nXtR e nde r. You ca n a lso sa ve to Pira ne si (.e px ) file form a t.

Rendering - 3.1

(32)

nXtRender Tone Mapping

Tone mapping is the proce ss of conve rting the lum ina nce da ta use d by nXtR e nde r into displa ya ble or printa ble R GB pix e ls. As you m ove your cursor ove r the nXtR e nde r R e nde ring scre e n, notice the num be rs on the sta tus ba r. The Va lue fie lds show the a ctua l da ta in the nXtR e nde r im a ge for the R e d, Gre e n, a nd Blue sub-cha nne ls. The da ta is lum ina nce , in units of ca nde la s pe r m e te r squa re d (cd/m ^2). The first thre e C olor fie lds show the re sulting R GB colors produce d a fte r tone -m a pping, a nd displa ye d in the i-m a ge . (The fourth C olor fie ld shows the Alpha , or tra nspa re ncy cha nne l, which is use d for com posting.)

The tone -m a pping controls a re loca te d in the uppe r right corne r of the re nde r scre e n.

Brightness - The Brightne ss control is the m ost im porta nt.

Adjusts the ove ra ll brightne ss. For e x a m ple , if a white surfa ce in your m ode l is re nde ring gra y, you ca n incre a se the brightne ss until the surfa ce a ppe a rs white . O r, if your e x te rior sce ne se e m s ove re x pose d, you ca n de cre a se the brightne ss until the sce ne a ppe a rs m ore corre ct.

The de fa ult se tting is 100 — sm a lle r num be rs produce da rk e r im a ge s. For m ost re nde rings, sm a ll cha nge s produce notice a ble e ffe cts.

Burn - Burn cha nge s the white point of the im a ge so tha t le ss tha n m a x brightne ss obje cts will m a p to white . Se e : Using Burn

Saturation - C ontrols the a m ount of color include d in the re nde ring. Slide it to the le ft to cre a te a gra y im a ge .

(33)

-nXtRender Color Maps

The Color' of e a ch m a te ria l is use d a s the Base Color for re nde ring - m a tte re fle ction a nd tra nspa re ncy.

Color Settings for a new Solid Color Material

RGB Color

C om pute rs use R GB color va lue s to proje ct color onto the m onitor. Ea ch pix e l on the m onitor ca n displa y a com bina tion of the se thre e colors to displa y the de sire d re sult. The sa m e color de finitions a re a lso use d for othe r outputs - such a s printing. In nXtR e nde r we de scribe ba se colors using R GB, a nd the n the colors a re m odifie d while re nde ring ba se d on lighting,

re fle ctions from othe r surfa ce s, e tc. C olors with te x ture s usua lly use the colors in the te x ture im a ge . Howe ve r the Ba se C olor ca n be ble nde d with the te x ture if de sire d.

Color Maps - 3.3

(34)

Adding and assigning materials

Material Basics

Adding Materials to a Drawing

Ma te ria ls ca n be a dde d to your dra wing in m a ny wa ys. He re a re a fe w:

Creating a new material

You ca n cre a te a ne w m a te ria l by using the dropdown button on the Ma te ria ls ta b of the nXtR e nde r Pa le tte . C hoose the a ppropria te te m pla te for your m a te ria l. The a ppropria te Ma te ria l Editor will be invok e d. This m a te ria l is store d in the curre nt dra wing only.

Load material from disk or library

Using the Ge t Ma te ria l from File button on the Ma te ria ls Ta b, you ca n im port .nXtMa te ria l file s for use in the curre nt dra wing. Ma ny m a te ria l file s a re a va ila ble for Downloa d .

Drop material from Windows File Explorer

You ca n dra g a nd drop a n .nXtMa te ria l file dire ctly from e x plore r into your AutoC AD dra wing.

Dropping a material from Windows File Explorer onto an object in AutoCAD:

(35)

-You a re a sk e d whe the r to a ssign the m a te ria l by la ye r or dire ctly to the obje ct, a nd a lso the m a te ria l is a dde d to the a ctive m a te ria l list in the nXtR e nde r control pa ne l.

Assigning Materials to Objects and Layers

Ma te ria ls ca n be a ssigne d to obje cts or la ye rs in your dra wing. If you use AutoC AD Archite cture (r) (form e rly Archite ctura l De sk top(r) or ADT) you ca n a lso a ssign m a te ria ls to AEC com pone nts.

There are many ways to assign a material to an object or layer. Here are a few:

Dra g a nd drop a m a te ria l from the pa le tte onto a n obje ct. You will ha ve the choice of a ssigning the m a te ria l to the obje ct or two the obje ct's la ye r.

Se le ct the m a te ria l in que stion a nd use the Atta ch Ma te ria l to O bje cts button. This m e thod a llows you to a ssign m a te ria ls to individua l fa ce s of 3dsolids by using AutoC AD's sub-obje ct se le ction m e thods.

Adding and assigning materials - 3.4

(36)

Dra g a nd drop a m a te ria l from the pa le tte onto a la ye r in the La ye r list.

Se le ct a m a te ria l from the pa le tte . Se le ct one or m ore la ye rs from the la ye r list. C lick the Atta ch Ma te ria l to La ye r button.

Dra g a nd drop the m a te ria l file from Ex plore r dire ctly onto a n obje ct in your dra wing. This m e thod a llows you to a dd a nd a ssign a m a te ria l in one ope ra tion. You will be prom pte d to choose the obje ct or the obje ct's la ye r.

Assigning Materials to ACA Components

nXtR e nde r m a te ria ls a re just AutoC AD m a te ria ls with som e a dditiona l da ta a tta che d to the m . If you use A utoCA D

A rchitecture (A CA ) you can attach an nXtRender material in the same way you would attach an A utoCA D native material. For e x a m ple , using Style Ma na ge r, you ca n a tta ch a n nXtR e nde r m a te ria l to a n AEC m a te ria l using the following proce dure :

Se le ct your m a te ria l unde r Multi-Purpose O bje cts->Ma te ria l De finitions. O n the Displa y Pope rtie s ta b, click the Edit Displa y Prope rtie s button.

Use the R e nde r Ma te ria l popdown list to se le ct your nXtR e nde r m a te ria l. The nXtR e nde r m a te ria ls will ha ve a pre fix of "AccuR e nde r-" be fore the m a te ria l na m e .

(37)

-Video Tutorial

Creating and using Materials Video

W a tch Vide o

www.youtube .com /wa tch?v=q0Dnl5Pnog4

In this Vide o, Da nie l will show you how to cre a te m a te ria ls a nd use m a te ria ls from libra rie s using nXtR e nde r for AutoC AD. C re a te a solid color m a te ria l, cre a te a m a te ria l with a te x ture , se le ct a nd pla ce m a te ria ls from libra rie s.

Additiona l

Additional Notes

Adding and assigning materials - 3.4

(38)

Use the AutoC AD _PURGE com m a nd to de le te unwa nte d, unuse d m a te ria ls from your dra wing. Ma te ria ls in use ca nnot be de le te d.

Ma te ria l a ssignm e nts by obje ct ta k e pre ce de nce ove r m a te ria l a ssignm e nts by la ye r. Use the R e m ove Ma te ria l from O bje cts button to re m ove m a te ria ls a ssigne d by obje ct.

To re m ove a m a te ria l a ssigne d by la ye r, se le ct the la ye r(s) from the La ye r list a nd click R e m ove Ma te ria l from La ye rs R e nde ring with AutoC AD using nXtR e nde r

(39)

-nXtRender Lighting

nXtR e nde r is de signe d to sim ula te re a l-world lighting. Use the following guide line s whe n lighting your m ode l:

Provide a ccura te inform a tion whe ne ve r possible . Avoid using unre a listic inte nsity le ve ls for light source s. Se t the units corre ctly for your dra wing by using the AutoC AD _UNITS com m a nd. The lighting will not be corre ct unle ss the units a re corre ct. For e x a m ple , if your dra wing is in m illim e te rs, m a k e sure tha t m illim e te rs is spe cifie d.

Adjust the ove ra ll brightne ss of your re nde ring by using the Brightne ss control on the re nde ring displa y. Do not

attempt to adjust the overall scene brightness by changing the intensity of all of the light sources. nXtR e nde r's

a utom a tic e x posure a djustm e nt will be work ing a ga inst you if you a tte m pt to do this.

Lighting Presets

nXtR e nde r provide s four lighting pre se ts which ca n he lp ge t you sta rte d whe n de ciding how to light your m ode l. The re a re m a ny m ore lighting options a va ila ble , but the pre se ts a re ofte n sufficie nt for m a ny diffe re nt re nde rings. The Pre se ts popdown list is a va ila ble on the Lighting ta b of the nXtR e nde r pa le tte . C hoose the Pre se t which m ost close ly re se m ble s your sce ne :

Studio m im ics the lighting which m ight be found in a photogra phe r's studio. It is m ost use ful for re nde ring sm a ll

to m e dium size d obje cts in isola tion.

Exterior is use d for da ylight sim ula tions of a rchite ctura l e x te riors. A sun a nd na tura l sk y a re sim ula te d. Interior Daylight a llows you to sim ula te a n a rchite ctura l inte rior during the da y, lit by na tura l light. Interior Lighting provide s a sim ula tion of a n a rchite ctura l inte rior a t night, lit by a rtificia l lum ina ire s.

Studio

The prim a ry lighting is provide d by a n high dyna m ic ra nge im a ge file (HDR I). The light from the HDR I ha s be e n a rtificia lly dim m e d, to re se m ble the inte rior lighting le ve ls of the studio. You ca n m odify the HDR I se ttings a nd file on the Sk y ta b. You ca n a dd a rtificia l lights to your sce ne using the Lights ta b. The visible ba ck ground in the Studio pre se t is bla ck .

Exterior

The sun a nd sk y se ttings ca n be m odifie d on the Sun ta b. You ca n spe cify sun a ngle s dire ctly or you ca n use ge ogra phica l loca tion a nd da te a nd tim e . The de fa ult visible ba ck ground for this pre se t is the sim ula te d sk y.

Interior Daylight

Use Inte rior Lights a s we ll a s sun a nd sk y for lighting.

For a n inte rior da ylight sim ula tion to work prope rly, you m ust use a tra nspa re nt m a te ria l to re pre se nt the gla ss in your windows. Sun a nd sk y se ttings a re sim ila r to the Ex te rior pre se t.

Lighting - 3.5

(40)

Also, you m ust a dd a rtificia l lights to your m ode l. Se e : The Lights Ta b

Interior Lighting

Use Inte rior Lights only.

For Inte rior Lighting to work prope rly, you m ust a dd a rtificia l lights to your m ode l. Se e : The Lights Ta b

Additional Notes on Presets

Indire ct lighting, the lighting re fle cte d off of surfa ce s, is on whe n one of the two inte rior pre se ts a re se le cte d a nd off for studio a nd e x te rior. This type of lighting is a ve ry significa nt com pone nt of a n inte rior sim ula tion. For e x te riors a nd studio m ode ls the e ffe cts of indire ct lighting is m ore subtle . You ca n turn on indire ct lighting for e x te riors a nd studio m ode ls if you wa nt this a dditiona l re a lism (a t a substa ntia l pe rform a nce cost.) Inte rior da ylight m ode a nd e x te rior m ode do not ha ve a rtificia l lights e na ble d. You ca n a dd a rtificia l lights to the se pre se ts if you wish by following the proce dure he re .

Night tim e re nde rings ca n be a little trick y. Se e this to ge t sta rte d.

Tutorials

Se e : nXtR e nde r Lighting Ba sics Tutoria l

(41)

-Adding lights

Adding Lights to Your Model

Use the following proce dure to a dd a n a rtificia l light to your dra wing:

Dra w a nd position the obje ct which will se rve a s your light source . O nce this obje ct is ta gge d a s a light source , it will e m it light in the pa tte rn you choose .

Use the Ne w Light dropdown button on nXt's Lighting ta b to se le ct a pa tte rn for your light. Four pa tte rns a re a va ila ble : //O m nidire ctiona l// distribute s light in a ll dire ctions e qua lly.

The //Spot// pa tte rn provide s a be a m which you ca n focus.

//Diffuse // provide s a n a pprox im a tion of a re ce sse d light with a diffuse r or ba ffle s.

The //Photom e tric// pa tte rn a llows you to use a m a nufa cture r's .ie s goniom e try file to de scribe the distribution. W he n prom pte d se le ct your obje ct (the Photom e tric pa tte rn will first prom pt you for your .ie s file .)

Provide a na m e for your light.

Hit e nte r to a cce pt de fa ult va lue s for the othe r prom pts.

Additional Notes:

By de fa ult, a ll lights will dire ct the ir light stra ight down. De pe nding on your sce ne , you m a y ne e d to a im your light in a diffe re nt dire ction. Be fore you be gin the a im ing proce ss, it is ofte n e a sie r to ha ve a ta rge t obje ct to sna p to. R ight click on the light in the list, a nd se le ct Aim < to a im your light. The diffe re nt pa tte rns will ha ve diffe re nt prom pts to follow. To cha nge the prope rtie s of your light, right click on the light in the list a nd se le ct Prope rtie s.

C lick he re for a dditiona l inform a tion on IES (Photom e tric) lights.

Adding lights - 3.6

(42)

Working with Plants

nXtR e nde r include s a fun a nd powe rful pla nt ge ne ra tor which e fficie ntly ge ne ra te s com ple x e ntoura ge obje cts during re nde ring. The se pla nts ha ve little im pa ct on dra wing size ; only a pla ce -holde r is k e pt in AutoC AD.

Two broa d ca te gorie s of pla nts a re include d. Tre e -lik e pla nts (including shrubs a nd house pla nts) a re distinct obje cts which a re inse rte d in spe cific loca tions. In a ddition, a n e x isting AutoC AD obje ct ca n be ta gge d a s groundcove r to m a k e it a ppe a r to sprout whe n re nde re d.

Creating Plants

R un nXtPla ntEditor64.e x e or nXtPla ntEditor64.e x e from the nXt folde r in Progra m file s to loa d the Pla nt Editor

Tree Editor usage

Plant Type

Se t the type from the File/New m e nu a t the top.

The re a re four tre e type s - Standard, Conifer, Broa d C rown, Pa lm and C om ple x (Do not use Groundcove r with R pTre e Ma k e r).

(43)

-Ea ch ha s diffe re nt se tting on the ta bs of the tre e e ditor. Pla y with the va rious se ttings to se e wha t the y do.

Trunk Settings

Working with Plants - 3.7

(44)

C ha nge the Pa ra m e te rs a nd se e the re sults a t the le ft. Foliage and Flowers

[[Im a ge :Tre e -e ditor-folia ge .jpg|500px ]

You ca n click on the le a f im a ge to se le ct a diffe re nt im a ge . Flowers/Fruit

You ca n a lso a dd a n im a ge to be use d a s flowe rs or fruit Leaf and Flower Images

You ca n se le ct ne w le a ve s, trunk , e tc. by click ing on the im a ge .

You ca n a lso a dd your own le a ve s a nd ba rk to the Pla nt Im a ge folde r a nd use the m for your custom tre e s. R e nde ring with AutoC AD using nXtR e nde r

(45)

-RayTrace

C lick 'Sta rt' on the R a yTra ce drop down m e nu to se e a sa m ple re nde ring of the tre e with folia ge . Use the m ouse a nd scroll-whe e l to on the im a ge to se t a ne w vie w be fore sta rting re nde ring if de sire d.

Working with Plants - 3.7

(46)

Obtaining nXtRender Plants

nXtR e nde r com e s with a full-fe a ture d, e a sy to use , Pla nt Editor which e na ble s you to cre a te your own pla nts. The Pla nt Editor is loca te d in the W indows Sta rt m e nu, unde r the folde r nXt.

The re a re a lso se ve ra l online source s for nXtR e nde r pla nts, including the Plant Library a nd Mixed-Content Library se ctions of the m a in nXtR e nde r we bsite :

http://www.a ccure nde r.com /pa ge /conte nt-a nd-e ntoura ge

To Insert an nXtRender Plant:

Se le ct W idge ts->Pla nts->Add... from the nXtR e nde r pa le tte m e nu ba r

Se le ct the .ArPla nt file you wa nt to inse rt Pick a Loca tion for your pla nt in the dra wing

C a nce l or pick a dditiona l Loca tions for a dditiona l insta nce s of the sa m e pla nt To Tag an object as nXtRender Groundcover:

Se le ct W idge ts->Pla nts->Add Groundcove r from the nXtR e nde r pa le tte m e nu ba r Se le ct the .ArGroundcove r file you wa nt to inse rt

Se le ct the obje ct to ta g

If you ta g a 3D Solid obje ct a s groundcove r, the groundcove r will ta k e on a "topia ry-lik e " a ppe a ra nce . A dditional notes on nXtRender Plants

Ma k e sure the units a re se t corre ctly for your dra wing. The AutoC AD _UNITS com m a nd or _INSUNITS syste m va ria ble controls this.

nXtR e nde r Pla nts ca n be sca le d, copie d, a nd rota te d.

W idge ts->Pla nts->R a ndom ize a llows you to se le ct a group of pla nts a nd ra ndom ize the ir sca le s a nd rota tions W idge ts->Pla nts->Id te lls you the na m e of a pre viously inse rte d pla nt

W idge ts->Pla nts->R e m ove Groundcove r a llows you to "unta g" a n obje ct pre viously ta gge d a s groundcove r. R e nde ring with AutoC AD using nXtR e nde r

(47)

-nXtRender Beyond the Basics

He lp in work ing with te x ture s, de ca l, HDR I sk ie s, R PC obje cts, e tc

HDR i Sk y for illum ina tion a nd re fle ction.

Livingroom by Ja n Ve rze le n

Chapter 4 - Beyond the Basics

(48)

Working with textures

Working With Textures Te x ture s a llow the use r to m a p im a ge file s onto the surfa ce of a m a te ria l. The re a re thre e wa ys to do this.

1. For a sim ple te x ture m a pping, go to Ma te ria ls → Ne w Ma te ria l → Te x ture d… You will be prom pte d to se le ct a n im a ge to m a p to the surfa ce of your m a te ria l. If the im a ge doe s not tile we ll, you ca n se le ct Mirror Tile s to re m ove the se a m s. 2. For a m ore sophistica te d te x ture d m a te ria l, go to Ma te ria ls → Ne w Ma te ria l → Te x ture Se t… This a llows you to im port

third-pa rty te x ture m a ps tha t conta in inform a tion such a s displa ce m e nt, norm a l, or bum p m a ps. Displa ce m e nt m a ps ca use the m a te ria l to ha ve de pth, which com e s a t a pe rform a nce cost. For the a ppe a ra nce of re lie f without this pe rform a nce cost, use norm a l or bum p m a ps.

3. For a dva nce d options, e ithe r click the Adva nce d… button in the Te x ture Se t dia log, or go to Ma te ria ls → Ne w Ma te ria l → Adva nce d… a nd the n click on the Te x ture Ma ps ta b. This inte rfa ce a llows you to control m ore de ta ils, such a s the he ight of the displa ce m e nt m a pping or which colors a re m a sk e d. It a lso a llows you to a dd m a ps a nd m a nua lly se t the m a p type , e .g. Sta nda rd, or Displa ce m e nt. For m ore inform a tion a bout a dva nce d options, click he re .

Non-tiling te x ture s ca n a lso be a pplie d dire ctly to obje cts, bypa ssing the m a te ria l a ltoge the r, by using de ca ls. W ork ing W ith Te x ture s

(49)

-Working with decals

Working with decals

De ca ls a re non-tiling im a ge m a ps which you a pply dire ctly to obje cts (inste a d of indire ctly via the obje ct's m a te ria l.) De ca ls ca n be use d to re pre se nt a va rie ty of visua l phe nom e na , including a pa inting hung on the wa ll, la be ls on ja rs, printe d signs, im a ge s on m onitors, e tc.

Use the following steps to apply a decal to an object: 1. Ex pa nd the O bje ct Prope rtie s ta b on the nXt Pa le tte 2. Se le ct the obje ct

3. R ight-click on the De ca ls list a nd se le ct Ne w

4. Se le ct e ithe r Pla na r or C ylindrica l De ca l a s a ppropria te

5. Follow the prom pts a t the com m a nd line (m a k e sure to Acce pt the de ca l by pre ssing Ente r whe n finishe d) The de ca l will a ppe a r in the list a nytim e the obje ct is se le cte d.

To remove a decal from an object:

1. Ex pa nd the O bje ct Prope rtie s ta b on the nXt Pa le tte 2. Se le ct the obje ct

3. R ight click on the de ca l you wish to re m ove 4. Se le ct R e m ove

The de ca l will no longe r a ppe a r in the list whe n the obje ct is se le cte d To reposition an existing decal:

Working with decals - 4.2

(50)

3. R ight click on the de ca l you wish to re position 4. Se le ct Edit Position a nd O rie nta tion

5. Follow the prom pts to re position (m a k e sure to Acce pt the de ca l by pre ssing Ente r whe n finishe d) To change the surface properties of a decal:

3. R ight click on the de ca l you wish to e dit 4. Se le ct Prope rtie s…

The De ca l Prope rtie s dia log box will a ppe a r a llowing you to cha nge m a ny of the surfa ce prope rtie s of your de ca l. R e nde ring with AutoC AD using nXtR e nde r

(51)

-Working with Reflection Shaders

Working with Reflection Shaders in the Adva nce d Ma te ria l Editor

Sha de rs a llow you to cha nge the a lgorithm use d by nXtR e nde r whe n it ca lcula te s re fle ctions. The de fa ult (Ba la nce d) sha de r is the be st choice for m ost m a te ria ls. Howe ve r the re a re tim e s whe n a nothe r choice m ight offe r be tte r pe rform a nce , conve rge fa ste r, or produce fe we r a rtifa cts in the proce ss.

Ma ny of the sha de rs de a l spe cifica lly with how a rtificia l light source s a re re fle cte d in a m a te ria l. The re a re two funda m e nta l a lgorithm s use d by nXtR e nde r to ca lcula te the se re fle ctions. The first is a "ra y ca sting" a lgorithm a nd the se cond is a "highlight" a lgorithm . The se two a lgorithm s a re m a the m a tica lly e quiva le nt a nd will e ve ntua lly produce ide ntica l re sults.

R e fle ction Sha de r choice s in nXtR e nde r a re :

Balanced. This is the de fa ult sha de r a nd is the corre ct choice for m ost situa tions. nXtR e nde r a utom a tica lly ba la nce s the two a lgorithm s ba se d on the Sha rpne ss of the re fle ction.

Glossy. This sha de r incre a se s the blurrine ss of the re fle ction a nd pre ve nts ra y-ca sting e ntire ly. No obje ct or light re fle ctions a re ca lcula te d. Use this sha de r to incre a se pe rform a nce a nd pre ve nt a rtifa cts for m a te ria ls with ve ry blurry re fle ctions. Som e re fle ctive subtle ty m a y be lost.

No Light Source Reflections. This sha de r e x clude s ra y-ca ste d re fle ctions of light source s. This is som e tim e s use ful in pre ve nting "spe ck le " a rtifa cts if your m a te ria l is blurry a nd your sce ne conta ins sm a ll, bright, light source s.

No Light Source Reflections and No Highlights. This option e x clude s a ll re fle ctions of a rtificia l light source s. O bje ct re fle ctions a re still ca lcula te d.

No Highlights. O nly ra yca sting is use d to ca lcula te re fle ctions of light source s. This sha de r is use ful whe n light source s a re la rge a nd the surfa ce in que stion is not too blurry. In the se ca se s, the highlight ca lcula tion ca n ta k e a long tim e to re solve .

Monte Carlo. O nly ra yca sting is use d to ca lcula te re fle ctions of light source s. The ra yca sting occurs in a n initia lly ve ry noisy wa y, a nd gra dua lly conve rge s to the corre ct solution. It is m ost use ful whe n the surfa ce is not too blurry. Both conve rge nce a nd fra m e ra te m a y slow whe n using this option.

Working with Reflection Shaders - 4.3

(52)

(53)

-Adding indirect lighting to an exterior rendering

A dding Indirect Lighting to an Exterior Rendering - using the e ffe ct of lighting re fle cte d from othe r surfa ce s - ca n a dd som e subtle ty a nd re a lism to your e x te rior re nde ring. In pa rticula r, the unde rside s of ove rha nging fe a ture s such a s e a ve s or ba lconie s ca n be re nde re d m ore a ccura te ly whe n using indire ct lighting.

This subtle ty, howe ve r, com e s a t a substa ntia l pe rform a nce cost. More pa sse s will be re quire d to re solve the im a ge , a nd e a ch pa ss will ta k e longe r.

Use the following ste ps to e na ble indire ct lighting for your e x te rior re nde ring: 1. O n the Lighting ta b, se le ct the Ex te rior pre se t.

2. C he ck Show Adva nce d Ta b.

3. O n the Adva nce d Ta b, cha nge Indire ct from O ff to Ex te rior.

Adding indirect lighting to an exterior rendering - 4.4

(54)

Combining daylighting and artificial lighting for an interior

rendering

By de fa ult, nXtR e nde r's Inte rior Da ylight pre se t doe s not a llow you to a dd a rtificia l lights. To com bine both type s of lighting use the following ste ps:

1. Se le ct the Inte rior Da ylight pre se t on the Lighting Ta b. 2. C he ck Show Adva nce d Ta b

3. O n the Adva nce d Ta b, cha nge Lights from O ff to O n. The Lights Ta b will a ppe a r a nd a llow you to a dd lights to your m ode l.

A dditional Notes:

Use a ccura te va lue s for your lights, da ylight se ttings, a nd window gla ss if possible .

Be ca use the sun a nd sk y a re ve ry m uch brighte r tha n m ost lights, you m a y not se e a lot of e ffe ct from a dding a rtificia l lighting to your da ylit sce ne . This is norm a l. Avoid the te m pta tion to a rtificia lly boost the powe r of your light source s. It is le gitim a te to turn the sun a nd sk y down som e wha t, a s the se a re ba se d on a cle a r, unim pe de d sk y. A m ulti-cha nne l re nde ring m a y he lp you ge t the picture you wa nt, while still pre se rving a ccura te da ta .

(55)

-Working with HDRIs

High dyna m ic ra nge im a ge s (HDR Is) a re 2D im a ge file s which conta in a m uch broa de r ra nge of va lue s tha n wha t is norm a lly found in a sta nda rd im a ge file , such a s a .jpg or .png. W he n the se im a ge s a re produce d using a sphe rica l proje ction, the y ca n be use d to light m ode ls. If the va lue s conta ine d in the HDR a re a ccura te , the n the lighting will be a ccura te . (Se e be low for m ore inform a tion on units.)

HDR Is ca n be use d in nXtR e nde r in m a ny diffe re nt wa ys. Two com m on use s for HDR I lighting a re a rchite ctura l (lighting a building e x te rior) a nd studio (lighting a product using HDR I for a m bie nt):

Using an HDRI to Light an Architectural Exterior O n the Lighting Ta b, se le ct the Ex te rior Pre se t. C he ck Show Adva nce d Ta b.

O n the Adva nce d Ta b, turn the Sun O ff.

O n the Adva nce d Ta b, cha nge the Sk y from Auto to HDR I At this point you ca n choose a spe cific HDR I using the Sk y Ta b.

This proce dure use s the HDR I a s a visible ba ck ground to your re nde ring. This m a y re quire a high-re solution HDR I to a void pix e lla tion a rtifa cts.

HDRi sky used for visual background, illumination and reflection:

Using an HDRI to Simulate Studio Lighting O n the Lighting Ta b, se le ct the Studio Pre se t. C hoose a spe cific HDR I using the Sk y Ta b.

This option use s a bla ck ba ck ground inste a d of visua lizing the HDR I dire ctly. It a lso re duce s the inte nsity of the HDR I by a fa ctor of 20X to sim ula te indoor lighting conditions.

---Additional Notes

nXtR e nde r a ssum e s tha t HDR Is conta in ra dia nce va lue s e x pre sse d in units of wa tts. All of the HDR Is a va ila ble via our we bsite a re built this wa y unle ss othe rwise note d. Howe ve r, this is ofte n not the ca se with HDR Is from othe r source s. The units in m a ny HDR Is a re not ca libra te d to re a l-world units of a ny sort. The inte nsity of the se HDR Is m a y ne e d to be a djuste d in orde r to a chie ve prope r illum ina tion le ve ls. Se e the se ction on ca libra tion be low.

Working with HDRIs - 4.6

(56)

The re a re m a ny diffe re nt wa ys to use HDR Is in nXt. In a ddition to the Sk y, a diffe re nt HDR I ca n be use d for e a ch of the thre e ba ck ground cha nne ls: Visible , R e fle cte d, a nd R e fra cte d Ba ck ground. Use the Ba ck grounds Ta b, C ha nne l control to individua lly control e a ch cha nne l.

Calibrating an HDRI sky

C re a te a ne w m ode l in AutoC AD a nd loa d nXtR e nde r Se le ct the Ex te rior lighting pre se t

O n the Adva nce d Ta b, cha nge the Sk y to HDR I O n the Sk y Ta b se le ct your HDR I

Sta rt W a lk About

C ha nge the proje ction to Pa nora m a

Pre ss re nde r a nd stop the re nde ring a fte r one or two pa sse s. W ha t you now ha ve is a re nde ring of your e ntire HDR I. Move the cursor ove r the im a ge while obse rving the Va lue of e a ch pix e l on the sta tus line . The units a re cd/m ^2. You ca n zoom in on the im a ge if re quire d to e x a m ine sm a lle r se ctions in m ore de ta il. He re a re som e guide line s to he lp you de te rm ine if the m a p ne e ds sca ling:

The a ve ra ge va lue for a cle a r sk y is a pprox im a te ly 8000 cd/m ^2 The a ve ra ge va lue for a n ove rca st sk y is a pprox im a te ly 2000 cd/m ^2

The a re a a round the sun ca n be quite bright. Va lue s of 100000 cd/m ^2 or m ore a re not unre a sona ble . The sola r disk itse lf ca n be m uch brighte r tha n this.

For night sce ne s, light source s the m se lve s a re bright. Va lue s of 3000 to 5000 cd/m ^2 a re not uncom m on for stre e tla m ps. The lum ina nce of the m oon is 2500 cd/m ^2. O the r obje cts should be quite da rk . Va lue < 1 cd/m ^2 a re com m on for obje cts lit only by e nvironm e nta l light.

If you de cide tha t your HDR I would be ne fit from sca ling, use the Inte nsity se tting on the Sk y ta b to e nte r your sca le fa ctor. R e pe a t the re nde ring a bove to va lida te your ne w se tting. Alte rna tive ly, you ca n use Lighting C ha nne ls to a djust the lighting m ore inte ra ctive ly.

(57)

-nXtRender Lighting Channels

Lighting Channels a llow you to a djust m a ny a spe cts of the lighting in your re nde re d im a ge in re a l-tim e , a fte r the re nde ring ha s be e n produce d. This is a ccom plishe d by a llowing you to cre a te up to 8 lighting "cha nne ls" in the im a ge . Ea ch light source in the dra wing, including the sun a nd sk y, ca n be a ssigne d to a cha nne l. O nce this im a ge is re nde re d a nd sa ve d, e a ch cha nne l ca n be individua lly sca le d in the Im a ge Editor . For e x a m ple , using this ca pa bility, you ca n produce da y a nd night inte riors with a single re nde ring. The following five ste ps a re ne ce ssa ry to produce a nd m a nipula te a m ulti-cha nne l im a ge :

You m ust te ll nXtR e nde r how m a ny cha nne ls you wa nt. Go to Lighting->Adva nce d->C ha nne ls a nd se t the num be r de sire d from 1 to 8. Ea ch a dditiona l cha nne l you a dd re quire s a n a dditiona l 12 byte s pe r pix e l inte rna lly. This is a lot of m e m ory, pa rticula rly for high re solution re nde rings. It m a y not be possible to com ple te your re nde ring on a 32 bit syste m .

You m ust turn on a ll of the pa rticipa ting lights. Lights which a re off will not contribute to the im a ge a nd will not be sca la ble . Be ca use you a re re nde ring with m ore lights, it m a y ta k e a little longe r. For e x a m ple , to cre a te a n inte rior im a ge which conta ins both na tura l a nd a rtificia l lights:

Lighting Channels - 4.7

(58)

1. Se le ct the Inte rior Da ylight pre se t. 2. Se le ct Lighting->Adva nce d->Lights->O n

You m ust te ll e a ch light source which cha nne l it be longs to. By de fa ult, Sun a nd Sk y a re se t to cha nne l 0, a rtificia l lights to cha nne l 1. The re a re controls for e a ch light source , including sun a nd sk y. Va lid cha nne ls a re 0-7.

Lighting Channel Names

Lighting C ha nne l Na m e s m a k e it e a sie r to k now which cha nne ls you a re m odifying in the nXtIm a ge Editor. R ight click on a light, se le ct Prope rtie s, The type in a na m e , a fte r, or inste a d of a cha nne l num be r.

Adjusting Lighting Channels

Afte r re nde ring, you ca n m odify the inte nsity of lights in e a ch cha nne l by click ing C ha nne ls in the re nde ring window. R e nde ring with AutoC AD using nXtR e nde r

(59)

-As you a djust the cha nne ls, the tone -ope ra tor will com pe nsa te . All of the tone m a pping controls a nd rule s still a pply. For e x a m ple , if you're trying to do a night a nd da y e x te rior using the sa m e re nde ring, you will a lm ost ce rta inly ne e d to a djust the tone -op brightne ss down for the night tim e sce ne .

Lighting Channels - 4.7

(60)

Using IES (photometric) lights

IES files (.ie s) a re photom e try file s which de fine the distribution of light from a light source . The se file s a re ofte n provide d by lum ina ire m a nufa cture rs. By using the IES file to de fine your distribution, ra the r tha n one of the sta nda rd distributions

a va ila ble (i.e . om ni-dire ctiona l, diffuse , spot), you ca n m ore a ccura te ly de pict your lum ina ire . In a ddition, the IES file ca n a lso be use d to de fine the inte nsity of your lum ina ire .

Use the following ste ps to a tta ch a n IES file distribution to a light source : C re a te the light in the usua l wa y.

R ight click on the light in the list a nd se le ct Prope rtie s... from the m e nu C ha nge the Light Pa tte rn to Goniom e try File

C lick the Browse ... button a nd se le ct the .ie s file .

Norm a lly you will wa nt to use the file to de fine the inte nsity of the source a s we ll. C lick the From File che ck box unde r Brightne ss to do this.

A dditional Notes:

The va st m a jority of IES file s a re k nown a s "Type C " goniom e try file s. The se a re supporte d by nXt. Type A file s a re occa siona lly use d by the a utom obile industry to de fine he a dlights, a nd type B file s a re som e tim e s use d to de fine floodlighting. Type A a nd B a re not supporte d in nXt.

IES distributions a lre a dy include the e ffe cts of lum ina ire e le m e nts such a s ba ffle s, re fle ctors, a nd diffuse rs. It is im porta nt to e x clude the se e le m e nts from the ca lcula tion by prope rly ta gging the non-source pa rts of your lum ina ire . IES distributions a re ofte n a ssym e trica l, so the proce ss of a im ing the source include s not just a ta rge t, but a rota tion a ngle a s we ll.

(61)

-nXtRender Rendering Engines

The re a re thre e re nde ring e ngine s. - Pa ck e t Mode , the Pa th Tra ce r, a nd the Hybrid Engine .

Pa ck e t Mode is the fa ste st for cre a ting quick re nde rings. I doe s this by ta k ing som e shortcuts on how light, re fle ction a nd tra nspa re ncy a re proce sse d. The othe r e ngine s use a m ore pre cise a lgorithm to proce ss the e nd re sult for e a ch pix e l, but sta rt out with a rough look ing im a ge for the first 100 or m ore pa sse s until the va rious ca lcula tions for a dja ce nt pix e ls sta rt to conve rge .

Rendering Engines

Packet Mode

Pa ck e t Mode a fte r 68 pa sse s

The Packet Mode re nde ring e ngine provide s high qua lity re nde rings quick ly by a pprox im a ting som e things light lighting a nd re fle ction using 'pa ck e ts'. Proce sse s pa ck e ts of ra ys. This produce s a ve ry good re nde ring in the shorte st tim e .

The Pa ck e t Mode proce sse s pa ck e ts of ra ys, while the Pa th Tra ce r a nd Hybrid Engine proce ss individua l light pa ths. Be ca use of som e shortcuts, such a s Da ylight Porta ls, a nd othe r a spe cts of the re nde ring proce ss, Pa ck e t Mode cre a te a usa ble im a ge in fe we r pa sse s. Pa th Tra ce r ofte n re quire s m ore pa sse s be fore the im a ge ge ts sm ooth.

Path Tracer

Rendering Engines - 4.9

(62)

Pa th Tra ce r a fte r 1500 pa sse s.

The Path Tracer proce sse s individua l light pa ths This re quire s m ore pa sse s, but produce s be tte r re sults.

The Path Tracer ca n provide a be tte r qua lity finishe d product for m a ny m ode ls (with a sim ple r se tup), but doe s so a t the e x pe nse of a m ore com ple x a nd tim e -consum ing ca lcula tion. The Pa th Tra ce r be gins by displa ying a ve ry gra iny or "noisy" im a ge which gra dua lly re fine s a nd be com e s sm ooth. This proce ss is k nown a s conve rge nce . Som e sce ne s will conve rge ve ry quick ly, othe rs will ta k e m a ny hours.

The Hybrid Engine

(63)

-Hybrid Engine a te r 625 pa sse s.

The Hybrid Engine is fa ste r pe r pa ss tha n the Pa th Tra ce r, a nd ha s spe cia l proce ssing of C a ustics for tra nspa re nt a nd re fle ctive surfa ce s.

This wa te r sce ne wa s re nde re d for 625 pa sse s - nine hours - with the Hybrid Engine :

Rendering Speed

In m a ny ca se s individua l pa sse s in Pa th Tra ce r or the Hybrid Engine a re fa ste r tha n Pa ck e t Mode , howe ve r the ove ra ll re nde ring proce ss m a y ta k e longe r to com ple te , be ca use you will ofte n ne e d m a ny, m a ny m ore pa sse s to a chie ve a good re sult.

As 16-core (or m ore ) proce ssors be com e a va ila ble , the n it will m a k e m ore se nse to use a m a ny, m a ny pa ss re nde ring solution.

Additional Notes

In ge ne ra l, im a ge s re nde re d using the Pa th Tra ce r will ta k e longe r to conve rge tha n im a ge s re nde re d using the Sta nda rd m e thod. Inte rior da ylight sim ula tions, pa rticula rly those sce ne s whe re the windows a re re la tive ly sm a ll, m a y ta k e m uch longe r. O n the othe r ha nd, the Pa th Tra ce r is le ss se nsitive to insta ncing, pla nts, a nd displa ce m e nt m a ps. Mode ls which re ly he a vily on the se fe a ture s m a y a ctua lly conve rge fa ste r using the Pa th Tra ce r.

The sta nda rd Pa ck e t Tra ce r a lgorithm produce s a ve ry high-qua lity sim ula tion. For m a ny m ode ls, the diffe re nce in qua lity be twe e n the Pa ck e t Tra ce r m e thod a nd the Pa th Tra ce r ca n be ve ry subtle , pa rticula rly if indire ct lighting is e na ble d. The diffe re nce in qua lity m a y not be worth the e x tra proce ssing tim e .

The Pa th Tra ce r is a lm ost a lwa ys e a sie r to configure a nd se t up tha n the Pa ck e t Tra ce r m e thod. Adva nce d se ttings such a s re fle ction sha de rs, da ylight porta ls, a nd a m bie nt lighting, a re not use d whe n the Pa th Tra ce r e ngine is se le cte d.

C e rta in a dva nce d e ffe cts, such a s ca ustics or blurry tra nsm ission, ca n be ca lcula te d with be tte r a ccura cy using the Pa th Tra ce r.

Slower Convergence

Rendering Engines - 4.9

(64)

Be ca use of som e shortcuts, such a s Da ylight Porta ls , a nd othe r a spe cts of the re nde ring proce ss, Packet Mode cre a te a usa ble im a ge in fe we r pa sse s. Path Tracer ofte n re quire s m ore pa sse s be fore the im a ge ge ts sm ooth. In m a ny ca se s individua l pa sse s in Pa th Tra ce r a re fa ste r, howe ve r the ove ra ll re nde ring proce ss m a y ta k e longe r to com ple te . R e nde ring with AutoC AD using nXtR e nde r

(65)

-Controlling tesselation-- smoothing curved objects

nXtR e nde r a pprox im a te s curve d solids with m e she s. You ca n control the de nsity of the se m e she s by using a com bina tion of AutoC AD's _FAC ETR ES syste m va ria ble a nd the Tesselation se tting on nXtR e nde r's O bje ct Prope rtie s ta b. The se two va lue s a ct toge the r. The product of the two de te rm ine the de nsity of the m e sh. Highe r va lue s produce de nse r m e she s. The se will a ppe a r sm oothe r, but will re quire m ore m e m ory a nd re nde ring tim e .

A dditional Notes

_FAC ETR ES ope ra te s globa lly a nd will a ffe ct a ll curve d obje cts in your dra wing. The Te sse la tion prope rty ca n be a pplie d to individua l obje cts. The Te sse la tion prope rty is use d by nXtR e nde r only a nd doe s not a ffe ct the AutoC AD displa y.

nXtR e nde r doe s not re spond to _VIEW R ES e x ce pt for the W a lk About displa y. Se e AutoC AD He lp for m ore inform a tion on _FAC ETR ES a nd _VIEW R ES.

Controlling tesselation-- smoothing curved objects - 4.10

(66)

Using Archvision RPC with nXtRender

R PC s (®) a re im a ge -ba se d "e ntoura ge " obje cts which ca n be inse rte d into your dra wing a nd re nde re d. Popula r R PC obje cts include pe ople , ca rs, a nd pla nts. Som e R PC s a re 2D "cutout" obje cts which a utom a tica lly orie nt the m se lve s to a vie w. O the rs a re 3D te x ture d m ode ls.

R PC C a r re nde ring with nXtR e nde r

In orde r to use ArchVision R PC s in nXtR e nde r you m ust downloa d a nd insta ll the plugin for Autode sk AutoC AD / AutoC AD Archite cture from ArchVision's we bsite. Be sure to insta ll the ve rsion of the plugin which m ost close ly corre sponds to your ve rsion of AutoC AD or AC A. The plugin provide s a n inte rfa ce within AutoC AD for downloa ding, inse rting, a nd e diting conte nt. A dditional Notes

Always use the RPC's "Cast Reflections" switch when working in nXtRender. Sha dows a nd re fle ctions will not be corre ct

unle ss this switch is se t.

A "post-proce ss" plugin is a lso a va ila ble for Adobe Photoshop(r). Since R PC s a re pre lit, be tte r re sults ca n ofte n be obta ine d by inse rting the m into finishe d re nde rings.

Pira ne si (®) a lso offe rs dire ct support for R PC s

R PC s inse rte d into AutoC AD a lso work prope rly with the AutoC AD na tive _R ENDER com m a nd. R e nde ring with AutoC AD using nXtR e nde r