Welcome back! Last time I checked some of V-Ray's basis. This time I decided to take a deeper look at transparent materials, and experiment with them a little. I have noticed high-end 3D renderers always feature some glass rendering when they want to showcase their rendering capabilities, so I did what others would do and went ahead to render some glass.
Like before, I started with a regular scene with a couple of primitives. I gave one material to the planes, and another one to the sphere.
In the V-Ray Material, there's not a “transparency” slider that you can tweak. Instead, you use the Refraction Color slider to tweak that. I gave the material a 50% transparency, and you can see the result below.
And this next image shows what happens when setting the transparency at 100%.
As you see in the image above, the material had an IOR of 1.6 (that was the default setting). The IOR is basically a measure of how much the view ray “bends” inside the glass surface, causing the objects behind the glass to deform. A value of 1 means no deformation of the appearance of objects behind the glass (that's what you need for store displays, for example) while other values will cause some deformation due to view-ray bending. I went ahead and tried a setting of 1 to see how it would look. I also decreased the transparency, so I could see the sphere clearly (with an IOR of 1, and a transparency of 100%, the sphere disappears).
For my next test I imported a head model, gave it a transparent material and set the IOR to 2.4 (a diamond). I also made it more reflective, as I showed last time.
And this is how it looks with less IOR.
Another thing I wanted to check is how the shadows look, so I changed the camera perspective. It is interesting to see the difference in shadows between the solid objects and semi-transparent objects. I also changed from a rectangle light to a point light (with a small radius) to generate harder shadows.
Learning V-Ray is a fun experience. Now I do think I have enough to start testing V-Ray with more complex scenes. We'll see how it goes!