Creating Believable Materials - Photographic Rendering with V-Ray for SketchUp - page 220

Note
IOR values for glass typically range between 1.5 (standard) to around 1.7 (dense
flint glass).
Of course, we haven't quite finished with our material yet. Having such a clear view
of what is going on in the outside dining area is a little too distracting for my tastes,
and not necessarily something that would be welcome in an exhibition or gallery type
space such as this.
To do something a little more appropriate, let's give our glass more of a frosted look.
As we will need a clear glass material for other objects in the scene, however, rather
than starting from scratch, we can keep what we have created so far and use it as
the base for a new material. To set that up, let's perform the following step:
1. Right-click on the Door_Glass material entry and choose Duplicate Materi-
al , and then select the duplicate and rename it Glass .
When it comes to creating a frosted effect for glass, the method or methods we use
will depend very much on the type of effect we are trying to recreate. Some frosted
effects are created by manufacturing the glass in such a way that the surface be-
comes one giant collection of bubbles or divots, thereby giving a completely distorted
and unclear (frosted) view of anything sitting on the opposite side of the glass.
More common production methods, ones that produce the kind of frosted look we
are perhaps more familiar with, would include acid etching and sandblasting. Some-
times, the imperfections or frosting is created on the surface of the glass, causing it
to be rough to the touch. At other times, however, the frosting is sandwiched between
two thin pieces of clear smooth glass, creating what appears to be an internal frost-
ing effect.
As we have said, which of these effects we want to create will determine which ap-
proach we take with our material. Generating the effect on the geometry itself would
perhaps be one way to go. This can be done either by using the modeling tools avail-
able in SketchUp, or we could use V-Ray's displacement/bump mapping capabilities
to create surface distortions at render time (that would mean using the Standard ma-
terial as opposed to the V-Ray Material being used here).