V-Ray for Rhino Manual - Rum

Double-sided material
Under Options of each material, you will find this Double-sided selection. Default setting is
checked. This option is particularly important for transparent material. When this option is
unchecked, light enter to the inside surfaces will not be rendered and show up black. The reason to
have this option is that sometimes you may want to uncheck this option when render object with
translucent material (See next page) in order to get the right texture.
Unless you want to create some special effects, please have this option checked
The double sided option will not have any affect on the shadows of the object
Translucent material
We've talked about changing the Diffuse color to get the degree of transparency we want to create
before. White means 100% transparent, black means 100% opaque. You can create translucent
materials with colors anywhere between white and black. But now we want to introduce a different
translucent material. It is related to special light absorption materials.
Open file: Translucency.3dm and render it, you will get image like below on the left. You will see that
colors where partitions meet the outside box and at the base of the box are darker. This is because the
thickness of the object changes and the light travel distance changes also. So the degree of light
absorption varies. To create this kind of material, you have to check the Translucency option under the
Refraction. Image on the right is the rendered result for Layer 02.
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