As discussed in previous posts, 3ds Max is a surface modeler. That means that materials on the surfaces of objects don’t take into account the thickness of the object. V-Ray has a clever tool for this that allows all kinds of fun, realistic effects-Translucency. V-Ray Translucency isn’t documented very well, and there is virtually no information on the internet about it. Today, we’ll take a look at how it works to make realistic glass.
First, lets set up the scene.
-3ds Max 9 SP1
-Floor: V-Ray plane with a Checker diffuse. Tiling 1 x 1 and black & white squares:
That sphere is a V-Ray Sphere with a radius of 3′. You can tell the render settings aren’t stock, so lets cover those next:
-Default lights = off
-Hidden lights = off
-V-Ray::Indirect illumination (GI) = on (GI caustics on for both Reflective and Refractive)
-V-Ray::Caustics = on
-V-Ray::Environment = on (skylight = white, reflection/refraction = black), can add HDRI later once materials are set…
Your render should look like the one above. Before we get too far, I want to get a baseline for a 1.6 IOR (Index of Refraction), which is what most glass is, set for our little 6′ diameter marble. Create a V-Ray material (as are all materials unless otherwise noted), set as follows:
-Diffuse = black
-Reflect = black
-Refract = white
-All other V-Ray materials = stock
Apply to our lone, 3′ radius marble, and we get this:
Lets call that one #1. Copy that one into 5 more V-Ray spheres, and we’ll number those as well. Now you’d figure that from the material used in #1, it should be a simple matter of turning on Translucency, and we’re done, right? Well, go ahead and try by making a new material like the material for #1, or copying it and doing nothing more than:
-Turn on Translucency -> Type -> Soft (water) model
-Make Thickness = 0’0.0″
Surprisingly, we now have a solid black marble!
What happenned? Come to find out, the thickness setting has a lot to do with the way the material is applied. In fact, it matters greatly how thick your material is where a ray of light passed into, around, and through to whether it appears translucent at all. If the thickness setting is too low, there will (by default) be no light refracted.
To show this phenomenon better, apply materials to a large, flat object with modest thickness and angle it to the camera with these settings.
Now lets adjust nothing more than thickness. As our spheres are 3′ in radius, set the thickness setting to 3′. No change! Now increase the thickness to 6′ (the diameter of the spheres):
Setting this to red (218, 0, 0), which is the color that light will escape the object as, yields:
For sphere #3, load the material from Easy Water Part 2:
Finally, #4 is just a semi-translucent, reflective sphere. To finish the scene, I added a HDRI environment (with a 3x multiplier) and the same HDRI map for reflections-all set in the V-Ray::Environment rollout. To bring out the environments, and to make the materials look like real glass, I added a dark grey in the reflection map/color for each V-Ray material (55, 55, 55):
Render times are due to a dual core 2.2GHz laptop I travel with! Soon I’ll go over caustics and show how the default light refraction (above) can be improved to look more realistic.
In the mean time, send me your glass renders!
Another article I did on V-Ray glass here.
And yet another I did is here.