Vray Wouter Tutorials Material Settings

5/28/2018 Vray Wouter Tutorials Material Settings

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V-RAY MATERIAL

SETTINGSauthor:

Wouter Wynen

brought to you by:


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2006 VisMasters. All rights reserved.VisMasters and the VisMasters logo are trademarks of ArchVision, Inc.

All other trademarks belong to their respective owners.


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V-RAY MATERIAL SETTINGSby:

Wouter Wynen

February 2006


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V-Ray Material Settings

The basic material settings tutorial explains almost all mate-rial parameters of the vray material. If you are new to vray,please read the basic render settings tutorial first, so you canstart this tutorial in the correct way.

The vray version I used for this tutorial is 1.47.03.

INTRODUCTION


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1. Set render settings

Open the render settings dialog and do the following:- set vray as the renderer- output size to 480*360px- global switches: turn off default lights- image sampler to adaptive QMC- antialising filter mitchell-netravali

- indirect illumination ON- Secondary bounces multiplier to 0,85- Irradiance map settings: - low preset - hsph subdivs = 30- environment: - skylight pure white color - reflection/refraction pure white, 1,2 multiplier- system: render region division 50*50 px

2. Create a test scene

Keep it simple. A teapot is a good object

for test renders, because of its shape. Thwhy it was one of the first 3d objects outhere!

Make two teapots on a larger plane if yowant to follow this tutorial as close as psible..

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3. Open the material editor

Open the material editor by pressing m on thekeyboard.

4. Load a V-ray material

Press the standard button in the material editor and selectVRayMtl from the list. Double click or drag and drop it into oneof the material slots.

5. Rename and color

Rename the material teapot1. The first parameter in the mate-

rial is the diffuse slot. This is the main color of the material. Thesquare next to it is a map slot, you can load bitmaps or othermaps here to texture the material. For now, simply make thecolor swatch a light orange color.


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Repeat the previous steps to make a verlight grey material. Rename this material

groundplane and assign it to the grounplane and small teapot. You should havesomething like in the image on the left.

6. Second material

7. First render

Hit render! Your image shouldlook similar to mine, if you haveset all render properties as instep 1. Make sure default lightsare turned off.

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Select the orange material in the mate-rial editor. Below the diffuse slot are the

reflection options of the material. Thecolor swatch next to reflect is the mainreflection control. Black means there is reflection at all, white means the materia

will become 100% reflective. If you makeit red for example, the reflections will betinted red.

First try a medium grey color.

8. Reflections

9. Render

Hit render. Notice the teapot becomes very reflective.

Try a very dark grey, and very light grey too to see the difference.


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Set the reflection color to pure white, aset the max depth parameter to 1 and hrender.

10. Max depth

You will notice that many are

turn black. The max depth cotrols how many times a ray creflect before the calculationstops. Max depth of 1 meansonly 1 reflection can take pla2 means a reflection of a refl

tion can exist and so on...

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Leave max depth at 1 andchange the exit color to red.Assign this material also to thesmall teapot.

Render again.

Now all reflections of reflec-tions turn red instead of black.

The max depth is a way tolower rendertimes in sceneswith lots of reflective objects.But by lowering the reflections,

the exit color will likely comeinto play. Sometimes it is there-fore usefull to change this toanother color than black; some-thing more appropriate for thescene for example.

11. Exit color

Reset the exit color to black and play with the max depth param-eter untill most of the black areas dissappear.

Usually you shouldnt go higher than 10. Higher numbers will onlywaist valuable rendertime for no visual improvement.

12. Max depth


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Fresnel reflection is a phenomenon that happens on almostall reflective surfaces. Parts of the surface that point directly atyou will reflect less than parts of the surface facing towards youunder a greater angle.

13. Fresnel reflections

Leave the fresnell IOR at 1.6and hit render. Notice themiddle of the tepot has weakerreflections than the sides. Thisis the fresnel effect.

Lower the fresnel IOR toincrease the effect. The loweryou go, the less it will reflect inthe middle. If you go really high,it will be the same as turningfresnel off (>25).

14. Fresnel reflections

The amount of the effect is controlled by

the IOR of the material. You can find thisin the refraction parameters. In real life,the fresnell effect is always linked to thisIOR. In Vray however, you can unlink them,setting a different IOR for reflection as for

refraction. To do this, click the small L nextto the fresnell checkbox. The fresnell IORbox will become available.

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Duplicate the orange material, rename it teapot 2 and assign it

to the small teapot. Change the diffuse color to a dark red.

16. Reflection glossiness

Select the orange material. Change the reflection color back to a

medium grey. Turn off fresnell reflections.

Change the reflection glossiness from 1.0 to 0.8.

15. Teapot 2


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17. Reflection glossiness

Hit render.The reflections are very blurry now. This is

the effect you get on real objects from verysmall bumps in the surface. To create thiseffect in 3D, you could also put a very fine

bumpmap in the bumpmap slot. But by usingthe glossiness parameter instead, renderingwill be a lot faster.

Play with the glossiness value to see what it

does.

Glossiness means shinyness, so glossi-ness=1.0 is 100% shiny, lower values are nonglossy or blurry reflections. There is muchconfusion about this, many people will mix

up the term glossy with blurry.

18. Smoother blurry reflections The subdivs value beneath the refl glossness controls the smoothness of the blu

reflections. Change it to 20 and render. Tresult is much smoother.

Note that 8 subdivs means 8*8=64 sam-ples, 20 subdivs means 20*20=400 sampDoubling the subdivs will take +-4 timeslonger to render!

Make sure you have the AA sampler atadaptive QMC when using high subdivsvalues!! If you want to use adaptive subd

sion AA, you can get away with much lowsubdivs values (3 to 10). The adaptive AAsmooths outs much of the noise fromthe low subdivs. If you have many blurryreflections in the scene, adaptive QMC walways be faster.

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19. QMC settings: smooth the blurry reflections even more

If you want the noise tobe even smoother, in-creasing the subdivs will

not always help. Dont gohigher than 40 trying to

reduce the noise. A bet-ter solution can be foundin the QMC sampler set-tings.

Open the render set-tings dialog and go to

the QMC sampler rollout.Change the noise thresh-old to 0.001 and renderagain. The noise will be

completely gone now,but at the cost of longerrendertimes.

The QMC sampler set-tings give you an easy wayto speed up test renders,by simply increasing the

noise threshold to 0.05for example. Note thatthe QMC sampler set-tings will also affect irradi-ance map calculation and

DOF, MB, Area shadows,etc... So reducing noisewill not only improveglossy effects, but also theGI quality etc...

For now, change thenoise threshold back to

0.005. While were here,go to the system roll-out and enable the vray

stamp (delete all textexcept the rendertimepart). You will see speeddifferences better thatway.

20. Highlight glossiness

You probably know highlights from the default maxmaterials. Well, these highlights are nothing morethan fake blurry reflections. A highlight is actually areflection of a bright lightsource.

In previous versions of vray, there was no way torender these fake highlights with vraymaterials. Atpopular demand, the developers brought fake high-

lights to the vraymaterial.

Note that these highlights will only appear if you uselights in your scene. The skylight will not generatehighlights.


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V-Ray Material Settings16

21. Create a spotlight

To see the effect of highlight glossiness, create a maxspotlight directed at the two teapots.

Turn down the skylight multiplier to 0.0 for this test. Wedont want any light to come from the sky.

In the spotlight settings, turn on shadows and choosevray shadows in the shadow type list.

22. Render

Render the scene.

The white part on the teapot

is the highlight glossiness; thefake blurry reflection. A maxspotlight is invisible to thecamera and to reflections, butwith this highlight glossinessparameter you can make it vis-

ible in reflections.


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23. Highlight glossiness linked

By default, highlight glossiness setting is linked tothe reflect glossiness parameter. this means thatwhen you use refl glossiness and you have lights inthe scene, the highlight glossiness will appear too.

24. Unlink it!

Press the L button next to thhighlight glossiness parameterThe highlight glossiness valuebecomes visible and is set to1.0

Hit render.... the highlight isgone!

A value of 1.0 means no highlight glossiness (like 1.0 forblurry reflection means noblurry reflection).



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25. Highlight glossiness only

If you want only the highlight glossiness to appear, and not thereflection glossiness, you will have to use a little trick.

Logically you would think that1.0 for refl gloss will turn them

off. This is true, but reflectionswill still appear, only sharp. Mix-

ing sharp reflections with high-light glossiness creates weirdunrealistic materials. Just try it.Set highlight gloss to 0.75 andrefl gloss to 1.0 and hit render.

Altough you may like thismaterial, it is not realistic. It is

reflecting the light source in a

blurry way, and the rest of theenvironment in a sharp way!Thats impossible in real life, asreflections dont make a differ-ence between lights and otherobjects.

26. Turn off reflections

So to be able to render highlight gloss only, you need toturn off reflections for the material. This is possible invray, but the setting is hidden in the options rollout ofthe vraymaterial.

Deselect trace reflections and render

again.

Note that now the material has only thfake glossy reflections. This material loolike a standard max material with somehightlights on it.


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27. Map slots

Next to all reflectionparameters is a map slot.This means you can con-trol reflection color, refl

glossiness, highlight glossi-ness and fresnel value bya map.

For example the reflec-

tion slot. Click it andchoose checker fromthe list. Make it visible inthe viewport so you cansee if it maps the objectcorrectly.

Set all other reflection

settings back to default(medium grey, no fresnel,all glossy=1.0, trace re-flections on). Delete the

spotlight and set skylightback to 1.0.

Hit render.

You will get somethinglike in my example. Allblack parts of the mapwill be non reflective, all

white parts are 100%reflective.

Try the same map in theother slots too. But takecare, white for glossi-

ness means a value of 1.0,so not blurry and black

means very blurry (value0.0 for glossy).


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28. Use interpolation

There is one checkbox left in the reflection parameters that Ididnt explain. The use interpolation checkbox. This can be usedto speed up the calculation of glossy reflections. It works more orless the same way as the Irradiance map for calculating GI.

When you check this box, you can adjust interploation settings in

one of the other vraymaterial rollouts.

I will not explain these settings, because I dont recommend usingthe interpolation for glossy reflections. They rarely look good, andwhen you want quality, they take almost as long as the standardglossy reflections.

The next section is about refraction


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Open 3d studio max and start a new scene.Open the render settings dialog and do the following:- set vray as the renderer- output size to 480*360px- global switches: turn off default lights

- image sampler to adaptive QMC- antialising filter mitchell-netravali- indirect illumination ON- Secondary bounces multiplier to 0,85- Irradiance map settings: - low preset - hsph subdivs = 20- environment:

- skylight pure white color - reflection/refraction pure black, 1.0 multiplier- system:

- render region division 50*50 px - frame stamp: delete all except the rendertime part

1. Start a new scene

2. Create the testscene

I suggest using the same kind ofobject as I did. A max teapot isnot good now because the meshhas holes in it, its not watertight

and you dont want that on re-fractive objects. I made this modi-fied torus knot because it will bean interesting shape to test with,because of all the curves andthin/thick areas.

If you want, use the exact samesettings as I did.


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3. Create materials

Make a medium dark blue vray-material for the groundplane, anda very light grey vraymaterial for

the torus knot and assign themto the corresponding objects.

Hit render, you should get some-thing like my example on the left.

4. Refraction parameters

Go to the white mate-rial and take a look atthe refraction param-eters. Refraction referstoo light rays getting

bent when going from

one medium to another.For example light travelsthrough air, then hitsa glass object and theray gets bent under acertain angle. Then thisray will travel further

through the glass, andeventually will leave it ata certain point, getting

bent again.

How much a ray getsbent depends on the

IOR (index of refrac-tion) of the material. Ahigh IOR means a lot ofbending, IOR=1.0 meansthe rays will not bend.

The vray material has alloptions available to cre-ate any kind of refractivematerial. As you can see,many options are similarto the reflection param-eters.

First, change the refractcolor to a medium grey

color.


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5. Refraction color

Render the image. You will notice the object has a trans-parent look. The grey refraction color means its about50% transparent.

6. Diffuse color

Change the diffuse to black and render again. The result is pretty

straightforward.


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7. Refraction color

Change the refraction color to pure whand render. The result looks weird...

Because now the object is 100% transpaent, the diffuse color has no effect at all

anymore. The black regions are rays thatget refracted to the environment color,which is black.

8. Adjust reflections

The previous step looks weird because usually materials withsuch refractive properties are also reflective. If you set thereflection to pure white, and check fresnel reflections, the ma-terial looks a lot better. The material you created now is thebasic setup for clear glass in vray.


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9. Create an environment

The rendering looks very boring, because the only thingto refract/reflect is the groundplane and the black envi-ronment color.

Create a large, thin box and position it more or less like

I did.

10. VrayLightMtl

The goal is to turn thisbox into a light source.An easy way to do this,is by using the special

VrayLightMaterial. Clickthe get material button

and choose VrayLightMtlfrom the list. Assign thematerial to the box andset the multiplier to 8.0


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11. Adjust skylight

Hit render. Its way toobright, because our sky-light is still active. Set theskylight multiplier to 0.0and render again. If its

too bright or too dark,you need to play with thevraylightmaterial multiplier

until it looks ok.

You can clearly see tha thelight is coming from ourbig box now, and the lightsource also reflects in thetorus knot. The contrast

between very bright lightand black environment is

very good for renderingglass or metal like objects.


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12. Refractive GI caustics

The light coming from thebox is not direct light as witha max spotlight. It is actuallytreated as first bounce GI (just

like the vray skylight). If youwould turn off GI and render,there will be no light at all.

Because of this, it is importantthat you leave the refractive GIcaustics in the indirect illumi-nation rollout ON. Try render-ing this scene without refrac-

tive GI caustics.

Youll see the shadows aremuch darker. The GI light is

now unable to pass trough thetransparent object (there areno GI caustics). Caustics are

noting more than refracted/re-flected light.

To continue, turn refractiveGI caustics On again. Also goto the irradiance map rollout

and set the preset to custom.Change the min/max rate to-4/-2 to speed up rendering.Note that the GI will be more

blurred now, but since wereonly testing, it doesnt matter.

There will be more on causticslater on in the tutorial. Fornow remember that you needto enable the GI caustics if youwant GI to pass trough trans-parent objects.


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13. Max depth

Increase the max depth parameter in theglass material to 10, both for reflectionsand refractions. Youll notice a bit morevariation in reflection/refraction. In somecases increasing the max depth really

helps to make your glass more realistic.It doesnt matter much here because our

environment is also black, just like the exitcolor when max depth is reached. In col-ored environments the max depth effectwill be more noticable.

To continue, reset the max depth to 5

14. Options: reflect on backside

Go to the options rollout of the glass ma-terial, and turn on the reflect on backsideoption. This will allow the inside of the

surface to also reflect the environment.When rendering glass, you should leave

this option turned on, it generates verynice and realistic inner reflections. Thisalso increases rendertime of course...

To continue the tutorial, turn it OFF again.


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The glossiness parameter is similar to the one for reflec-tions. Its use is to blur the refractions. This is one of themost time consuming settings, rendertimes will go reallyhigh if you use high subdivs...

Try a value of 0.8 with 8 subdivs. Youll see that theblurry refractions are very noisy due to the low subdivs.But you get the idea.

Turn the glossiness back to 1.0

15. Glossiness


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16. Index Of Refraction

Set the IOR to 1.0 and render. The torus is gone! This is

because no rays get bent with this IOR value. Becausefresnell IOR is linked to the refraction IOR, this is alsoset to 1.0, which means the object becomes non reflec-tive too. The refraction color is pure white, so the raysdont become tinted either! All this makes the torus

dissappear.

17. IOR

Unlink the fresnel IOR, so that its value is set to 1.6 again.Hit render.

The thing you see now is purely created by reflections.

18. IOR

Set the refraction IOR to 1.1 and render again.

Each material has its own IOR value. Typical glass valuesare around 1.6. Do a google search for other commonused material IORs.

Render a few tests with different IOR values.

Reset the IOR to 1.6 to continue.


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19. Exit color

Like with reflection, theres also an exitcolor for refractions. After a ray has re-fracted the max depth number of times,this exit color will come in to play. tick t

checkbox and give it a flashy green colorHit render. You can clearly see what partof the image go over the max depth number (5).

Make the exit color black again.

20. Fog color

The fog color is used to tint the refractions with a certaincolor. Thicker areas will become darker (more colored) thanthinner areas. Try a light red color for fog and render.

The material is very dark, but the thinner parts show sometransparancy.

The fog color and fog multiplier are actually an absortioncontrol. The light looses its energy while traveling throughthe material. The longer it travels, the more energy will beabsorbed by the object. Thats why thinner parts will remainlighter than the thicker parts.


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Change the fog multiplier to 0.05 and render again. The fog effectis much weaker now, letting more light pass through, resulting in alighter material.

21. Fog multiplier

You should experiment with different fogcolor/multiplier ratios. For example a light

but very saturated color with high multiplier,or a dark unsaturated color with a very lowmultiplier. You can get very different effectsby playing with this relationship.

22. Refraction color

You probablythink, whatsthe use of the

refraction colorthen??

Well, set fogoptions back

to default, andchoose a redrefract color. Hitrender.

The glass is

coloured too,but withoutthe absorbtion

effect. Thin andthik areas are

equally coloured(the dark areasare refractions

of the black envi-ronment!).

I usually use purewhite for refract

color and playonly with thefog options. Butexperiment withdifferent refractcolor/fog set-

tings to see whatthey do. Remem-ber, dark refract

color means lesstransparency.

The saturationof the color hasa huge impact

on the look ofthe refraction.A very darksaturated colorwill look very

similar to a verydark unsaturatedcolor in thecolor swatch, butit will be com-pletely different

when used forrefract color orfog color. Just

try it!


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23. IOR=1.0 mixed with fog

Adjust refraction settings to the ones onthe right. By mixing an IOR of 1.0 with fogcolor, you get a waxy kind of material.

24. Glossiness + IOR=1.0 + fog

Adjust the glossiness to 0.75 and the sub-divs to 16 and render again. The materiallooks a bit like reflective wax.

Turn glossiness to 1.0 again and IOR to 1.6before continuing.


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25. Affect shadows

An important option we didnt touch yet, it the affectshadows checkbox. It will have no effect in our test

scene because there is no direct light, only GI light. Theaffect shadows options is only used with direct lightrays.

Therefore, we will replace the light box with a VrayArealight. Go to the create panel and choose lights,and from the dropdown menu choose Vray.

25. Vraylight

Click and drag in a viewport to create the vray rect-angular light. Make the size the same as our box, andposition it in the same way. After that, hide the box.Set the vraylight settings as in the image on the right(click to enlarge). The multiplier should be equal tothe multiplier of the vraylightmaterial you used on

the lightbox.

We now created a lightsource exactly the same asthe lightbox, but it will cast raytraced area shadows.

26. Affect shadows

In the glass material, turn ON affect shadows and hitrender.

The image should look like mine. As you can see, itcasts green shadows. This is because the affect shad-ows option and fog color is used.

Rendertime increases because the shadows areraytraced.


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27. Affect shadows OFF

Turn affect shadows OFF and rendagain. Notice the shadows are diffeent now. This is because the GI catics come back into play. This imag

is the physically correct one! Whe

you have the affect shadow optionturned ON, no refractive GI caustare computed for that material, thare automatically turned off by V-rThe affect shadow option is nothimore than a fake caustics option. imagine that when using the affectshadow option, refractive caustics

would not be turned off automaticly, you would get a fake caustic effAND a real GI caustic effect on to

of each other! Thats why vray au-tomatically turns off GI caustics fomaterials that have the affect shadoption turned on. THIS IS VERY IMPORTANT TO UNDERSTAND!

Use the affect shadows option whyou want light to pass trough re-fractive objects, and you dont wanto enable refractive GI caustics, or

when you dont use GI at all, orwhen youre using Max lights. Maxlights will never produce refractivGI caustics! So if you want the ligh

of max lights to pass trough refractive objects, you MUST use the affshadow option.

The second image on the rightis rendered with an omni light asthe only lightsource, and the affect

shadows option is turned off. Notthe black shadows, no light passesthrough the material.


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The third image has affectshadows turned on. Thereis a fake caustic effect butits nowhere near physicallycorrect.

Note that the vray light is a

special light. Altough it casts

direct light just like maxlights do, they do produceGI caustics (max lightsdont!). Normally only firstbounce GI light (like thelight coming from skylightand object lights like ourlightbox) produces GI

caustics.

If you want real causticswhen using max lights, youneed to enable caustics inthe caustics rollout (=pho-ton mapped caustics). Dontdo this right now, these

caustics controls need atutorial of their own... Justremember that you can getnice caustics effects by us-ing GI and vraylights much

easier.

That is why I prefer usingthe lightbox or vraylight

over the max lights. Yousimply check the GI causticsoption and you dont haveto care about other causticsettings all over the place!Drawback is that you needto have good GI settingsfor the caustics to be sharp,

resulting in longer render-times. Another advantageof vraylights or objectlightsis that they reflect/refract

in your objects. Max lightsare invisible to camera andreflection/refraction.

So to summarize:1. If you use only objectlights and vraylights and you

want caustics:

- enable GI caustics - use good quality GIsettings to make sure thecaustics look sharp.

2. If you use max lights andyou want the light to passthrough refractive materials:

- use the affect shadowoption for a fake caustic

effect - OR enable caustics inthe caustics rollout and playwith the settings for photon

mapped caustics.

3. If you use vraylights andyou want photon mappedcaustics: - Disable affect shadows

- Disable GI caustics

- Enable caustics in thecaustics rollout and playwith the settings.


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28. Final material

Use the material settings as in the image on the right. I low-ered the fog multiplier a bit, and upped the max depth valuesboth to 8.

29. Final image setup

In the irradiance map settings, change everything as in the

image on the right. Also go to the QMC sampler rollout andchange noise threshold to 0.001 for maximum quality.


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30. Final imageRender the image, it should look something like mine.

Notice the nice caustics and area shadows, controlled by the

IR map settings. No caustics were enabled in hard to findplaces, no time consuming raytraced shadows were needed.

31. Comparison with QMC GI

As a test, I rendered

the image with QMCGI instead of irradi-ance map for first

bounce. QMC GI isnot an approximatemethod like IR mapwith its undersam-pling algorithm. QMCGI calculates the GIwithout compromise,every light sample

gets equal attention.So its a good test tocompare how wellthe GI with IR map iscomputed.

As you can see,

in the areas withmuch lighting detail,the QMC GI image

looks better (=morephysically correct)than the IR mapone. But it takes 10minutes comparedto 1m24s for the IRmap version... If youwant more detailed

GI with IR map, youneed to edit some ofthe IR map settings.


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32. Better IR map settings

This last image is rendered with optimized IR map settings. Asyou can see, this comes very close to the QMC GI example,but without any noise on the floor. I will explain how to opti-mize the IR map settings in an upcoming tutorial.


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This is a new section

1. Translucency

Transparent materials like clear glass or water will letlight travel through it undistorted (except for the bend-ing due to the IOR). Translucent materials will scatterthe light when traveling through it. For example stained

glass, wax, grapes, etc...

Stained glass can be made with vray by using the refrac-tion glossiness parameter, but wax or grapes for exam-ple will need the translucent controls. When to use thetranslucent controls or not, is a but unclear.

Usually translucency is used for really opaque materi-als in which light can penetrate a certain distance, if itsstrong enough. Examples are wax, human skin, orange

juice, milk etc... You cannot see through these materi-als, but light will be able to go through it partially and

scatter around. For example when you hold a strongflashlight under your hand, the other side will turn red(blood!) and you can see where your bones are locatedbecause they block the light.


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2. Translucency in Vray

Because the translucency controls are a bitstrange in behavior, I will not try to explainthem... More technical explanations can be fouin the online documents, and I believe the vrateam is working on a translucency tutorial...

You can get very similar results with extremedifferent combinations of settings, but when

seen under changing lighting conditions, they wreact very differently.

The translucency controls also depend on therefraction glossiness and fog settings. They wotogether, and especially the fog color is a verysensitive setting that will have a very drastic efect on the material. One thing you should ne

do, is using colors that have one of their compnents set to 255!!!

I usually leave the translucency color pure whthe refracion color a grayscale value and thencontrol the material color with the diffuse andfog color. Then with the fog multiplier and tralucency light multiplier create various effects olight passing through.

3. Skin

Heres a skin material that you can useto study the settings. Play with it and tryto understand what effect each param-eter has on the final look. Note thatbecause of the use of both reflectionand refraction glossiness, this materialwill render very slowly, especially with

these high subdivs values.


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4. Reset all settings from the previous page

In the end of the previous page, all settings werechanged for the final image. We need to set it back totest render values now.

Open the render settings dialog and do the following:- output size to 480*360px

- global switches: turn off default lights- image sampler to adaptive QMC

- antialising filter mitchell-netravali- indirect illumination ON- Secondary bounces multiplier to 0,85- Irradiance map settings: - low preset - hsph subdivs = 20- environment: - skylight pure white color

- reflection/refraction pure black, 1.0 multiplier- system:

- render region division 50*50 px - frame stamp: delete all except the rendertime part

5. Create a chrome material

Create a new vraymaterial and adjust the settings as in

the image on the right. This is a basic chrome materialsetup. Assign this material to the torus knot object anddo a quick test render. It should look like my testimage.

Now change the reflection glossiness to 0.7 before youcontinue.


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6. BRDF

In this rollout you canchoose between blinn, phongor ward shader. The effect of

these three types is noticablethe most when using glossyreflections. Render the scene

with the three different shad-ers. The settings affect howthe highlights will look like.

Ward is commonly used formetallic materials.

7. Anisotropy

Anisotropic reflections are reflectionsstretched in some direction. You see this

often on brushed metals, for example thebottom of cooking pans. The anisotropy set-

ting controls the shape of the highlight.

The torus knot is not the best example, butyoull get the point.

Change the anisotropy setting to -0.6 andrender the image. Theres also a huge dif-ference between phong/blinn/ward here.

Try some other values too (like +0.6 for

example).

The XYZ axis option allows you to changethe direction of the reflections, or you canuse a mapping channel instead. The rotationparameter rotates the reflections...


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8. Options rollout First set anisotropyto 0.0 again, andalso refl glossinessto 1.0.

Trace reflectionsand trace refrac-

tions is pretty

simple, they simpleturn of calculationof either two.

The cutoff param-eter is a tresholdvalue for vray totrace reflections

any further or not.Try a value of 0,7

on the current im-age. Increasing thethreshold can speedup rendering whenyou are using lotsof reflections in the

scene.

Double sided: pleaserefer to the manual.

Reflect on backside.

We used this optalready on page 2of this tutorial. Ifturned on, reflec-tions for back facsurfaces will becomputed too.

Use irradiance mif you turn this ofthe irradiance mawill not be usedon this material.Instead, the GI onthis material willbe computed wit

QMC GI. This canbe usefull if the ir

radiance map bluout small shadowdetails on certainobjects.

Treat glossy rays

GI rays: please reto the manual.Energy preservatmode: please refeto the manual.

9. Maps rollout

The maps rollout sumsup all different texturemaps. Almost all mapscan be accessed in thebasic parameters rollout(the small squares next

to the parameters), butsome will appear onlyhere.

These are the last fourmaps: bump, displace,opacity and environment.

Bump allows you to ren-der irregularities in the

surface by using a map.Dark areas in the mapare low areas, brightareas are high areas.

Displacement is likebump, but instead of fakerendering it, the actualmesh is deformed tocreate the irregularities.Refer to the manual for

extensive tutorials andexamples about displace-ment.

Opacity is the same asyou are used to in stan-dard max materials.

Environment slot allowsyou to use different re-

flect/refract environmentfor each material.


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10. Reflect/refract interpolation

These rollouts contain parameters to control reflect/re-fract interpolation. These are only needed if you tickedthe use interpolation checkbox in the basic parametersrollout. I dont recommend using interpolation for glossy

effects. If you do want to use them, please refer to the

manual for more detailed information.


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About the author

Wouter Wynen has studied product development for5 years at the university in Antwerp, Belgium. Duringthese years, his intrest in 3D modeling and visualisationgrew more and more. In the end, it even overpoweredthe intrest in product design.

After graduation, he founded the company Aversis, of-fering 3D viz & webdesign services.



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Vray Wouter Tutorials Material Settings

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