Vray Tutorials |
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Vray Basic material settings |
| Page 1 - Page 2 - Page 3 |
Before you start
If you discovered this Vray tutorial page through a direct link or search engine, please note that you're on page 3 of the tutorial! Please complete page 1 and 2 first if you haven't done so.
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1. Translucency
Transparent materials like clear glass or water will let
light travel through it undistorted (except for the bending due to the IOR).
Translucent materials will scatter the light when traveling through it. For
example stained glass, wax, grapes, etc...
Stained glass can be made with
Vray by using the refraction glossiness parameter, but wax or grapes for example
will need the translucent controls. When to use the translucent controls or not,
is a but unclear.
Usually translucency is used for really opaque
materials in which light can penetrate a certain distance, if it's strong
enough. Examples are wax, human skin, orange juice, milk etc... You cannot see
through these materials, but light will be able to go through it partially and
scatter around. For example when you hold a strong flashlight under your hand,
the other side will turn red (blood!) and you can see where your bones are
located because they block the light. |
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2. Translucency in Vray
Because the translucency controls are a bit strange in
behavior, I will not try to explain them... More technical explanations can be
found in the online documents, and I believe the Vray team is working on a
translucency tutorial...
You can get very similar results with extremely
different combinations of settings, but when seen under changing lighting
conditions, they will react very differently.
The translucency controls
also depend on the refraction glossiness and fog settings. They work together,
and especially the fog color is a very sensitive setting that will have a very
drastic effect on the material. One thing you should never do, is using
colors that have one of their components set to 255!!!
I usually
leave the translucency color pure white, the refracion color a grayscale value
and then control the material color with the diffuse and fog color. Then with
the fog multiplier and translucency light multiplier create various effects of
light passing through. |
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3. Skin
Here's a
skin material that you can use to study the settings. Play with it and try to
understand what effect each parameter has on the final look. Note that because
of the use of both reflection and refraction glossiness, this material will
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 were changed for the final image. We need to set it back to test render
values now.
Open the render settings dialog and do the following:
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output size to 480*360px
- global switches: turn off default lights
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image sampler to adaptive QMC
- antialising filter "mitchell-netravali"
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indirect illumination ON
- Secondary bounces multiplier to 0,85
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Irradiance map settings:
- "low" preset
- hsph subdivs = 20
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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 |
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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 material setup. Assign this
material to the torus knot object and do a quick test render. It should look
like my testimage.
Now change the reflection glossiness to 0.7 before you
continue. |
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6. BRDF
In this
rollout you can choose between blinn, phong or ward shader. The effect of these
three types is noticable the most when using glossy reflections. Render the
scene with the three different shaders. The settings affect how the highlights
will look like.
Ward is commonly used for metallic materials.
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7. Anisotropy
Anisotropic reflections are reflections stretched in
some direction. You see this often on brushed metals, for example the bottom of
cooking pans. The anisotropy setting controls the shape of the
highlight.
The torus knot is not the best example, but you'll get the
point.
Change the anisotropy setting to -0.6 and render the image.
There's also a huge difference between phong/blinn/ward here. Try some other
values too (like +0.6 for example).
The XYZ axis option allows you to
change the direction of the reflections, or you can use a mapping channel
instead. The rotation parameter rotates the reflections... |
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8. Options rollout
First set anisotropy to 0.0 again, and also refl
glossiness to 1.0.
Trace reflections and
trace refractions is pretty simple, they simple turn of calculation of either
two.
The cutoff parameter is a treshold value for Vray to trace
reflections any further or not. Try a value of 0,7 on the current image.
Increasing the threshold can speed up rendering when you are using lots of
reflections in the scene.
Double sided: please refer to the
manual.
Reflect on backside. We used this option already on page 2 of
this tutorial. If turned on, reflections for back facing surfaces will be
computed too.
Use irradiance map: if you turn this off, the irradiance
map will not be used on this material. Instead, the GI on this material will be
computed with QMC GI. This can be usefull if the irradiance map blurs out small
shadow details on certain objects.
Treat glossy rays as GI rays: please
refer to the manual.
Energy preservation mode: please refer to the manual. |
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9. Maps rollout
The maps rollout sums up all different texture maps.
Almost all maps can be accessed in the basic parameters rollout (the small
squares next to the parameters), but some will appear only here.
These
are the last four maps: bump, displace, opacity and environment.
Bump
allows you to render irregularities in the surface by using a map. Dark areas in
the map are 'low' areas, bright areas are 'high' areas.
Displacement is
like bump, but instead of fake rendering it, the actual mesh is deformed to
create the irregularities. Refer to the manual for extensive tutorials and
examples about displacement.
Opacity is the same as you are used to in
standard max materials.
Environment slot allows you to use different
reflect/refract environment for each material. |
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10. Reflect/refract interpolation
These rollouts contain parameters to control
reflect/refract interpolation. These are only needed if you ticked the 'use
interpolation' checkbox in the basic parameters rollout. I don't 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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