This page provides a step-by-step guide to V-Ray Materials and how to prototype different materials.
In this tutorial we are going to take a closer look at V-Ray materials and the advantages they can offer over Modo materials. We will look at V-Ray’s standard Material with the GGX BRDF option, V-Ray’s Blend Material, and V-Ray’s Fast SSS2 material. We begin with the headphone scene from the previous tutorial but with a close-up of the ear cup. We will be prototyping 3 different materials.
To follow this tutorial, you will need to have the V-Ray for Modo plugin installed.
This tutorial is a companion to go along with the two QuickStart videos posted on our YouTube channel.
To download the files used in this tutorial, please click on the button below.
Creating a V-Ray GGX shader
1) Creating a Nickel Material
We'll start by locating the original Nickel material in the Shader Tree, and adding a new V-Ray Material inside the material mask.
Click Add Layer > V-Ray Materials > V-Ray Material.
In Modo 10.2, the search feature can be used to easily add a new V-Ray Material.
Be sure to place it above the standard Modo material, overriding it.
2) Nickel Parameter Settings
To create the parameters of a Nickel material, we'll have to modify a couple of values.
Since it is a metal, we know there will be no diffuse reflection. Set the Diffuse color to black.
For the reflection color, use Modo’s color picker to select a measured value for nickel. Clicking on the color next to the Reflection color parameter brings up the color picker.
Use the drop-down menu below the large color box to select the Metals color presets. Click the Cog icon on the right and set the Browser Mode to List, and then scroll down and select the Nikel preset (the spelling of "nickel" in the Foundry presets).
To use the measured metal presets you must have the Modo content packs installed. They are available on the Foundry website.
Next, increase the Refraction IOR of the material to 60.0 to create ensure a strong specular reflection. The Reflection IOR is connected to the Refraction IOR by default .
3) Roughness Maps
Select the roughness map in the Shader Tree, and change its effect to V-Ray Reflection Glossiness by right clicking on its effect box.
You will need to enable the Invert option for the map because glossiness values in V-Ray work in the opposite direction to Modo. The map’s Opacity is set to 15%, so it will only partially override the underlying material glossiness.
Then ensure that your new V-Ray material is set to a similar gloss value as the original material: The Modo material has a roughness of 25%, which means that the equivalent setting in the V-Ray Material is a Reflection Glossiness of 0.75.
Finally set the BRDF Type to GGX.
Do a test render with V-Ray RT.
The render should be visually similar to the original.
4) GGX Tail Falloff
Now you can test the results of altering the GGX tail falloff. Set the value to 1, and draw a render region around the bright highlight on the ear cup and render again with V-Ray RT. Note the substantial difference that using a lower value makes: the highlights are much broader.
Setting a lower value in the GGX tail falloff will create wider specular lobes, and setting higher values will create narrower ones.
Set the GGX tail falloff value to 1.75 and render again. This value is closer to the original but still has a wider specular lobe. Having this level of control over the specular tail allows for very powerful fine-tuning of reflective materials such as metals.
Creating a V-Ray Blend Material
Now we will create a more complex blend material: a colored anodized aluminum.
5) Setting up the materials in the Shader Tree
Duplicate the existing V-Ray nickel material and use the Modo color picker to set the color to the aluminium preset.
Add a V-Ray Blend Material above the other V-Ray materials in the Shader Tree.
Finally, set the Base material as the aluminum material created in the previous step.
6) Adding Flakes
Next, add a V-Ray Flakes material below the Blend Material, and set Flake Scale to 0.002 and Flake Density to 0.8. This will give us many small flakes in our material.
In the V-Ray Blend Material, set the V-Ray Flakes as the Coat Material 1 slot. Let's give a quick look at the result in RT.
The first thing you'll notice is that the yellowish tint of the nickel is replaced by the bluish tint of the aluminum, which is driving the specular color of this metal. You can also see the V-Ray Flakes layer adding an extra detail level of sparkles.
7) Adding a colored dioxide coat to the Blend material.
Next, we will create a dielectric coating for the anodized aluminum. Add a new V-Ray Material under the Blend material. Set the Diffuse color to a bright blue and the Reflection color to pure white. Add this material to the Coat Material 2 slot in the V-Ray Blend Material.
The results of the render should look like this:
8) Fine Tuning
To finish off, let's lower the intensity of the flakes layer in the Coat Material 1 slot by setting Amount 1 to 0.15.
Go to the aluminum base material lower down in the Shader Tree, and set the GGX tail falloff to 3.0 to tighten the highlights.
Do a final render.
Creating a V-Ray Fast SSS 2 material
9) Setting up the material
In the final example, you will create a translucent plastic. Add a V-Ray Fast SSS2 material above the all the other V-Ray materials in the Shader Tree to override them.
Leave the Diffuse Amount at zero, and set a bright red as the Sub Surface Color.
Do a test render with V-Ray RT.
The Specular Glossiness is a little low, so increase it to 0.7 to tighten up the highlight. Do another test render.
10) Final Render Comparison
You should now have three different materials all created using unique aspects of the V-Ray material system.