The first editable parameter is map colors. Both of these colors will be actively blended using the Falloff type selected for the map. Texture maps or other maps can be used in place of colors as well. For the examples the Falloff is placed in the diffuse slot. The default colors are black (0,0,0) and white (255, 255, 255).

The name of the group is at the top of this rollout. This name changes depending on the falloff type selected, which is covered below. In all cases, the name on the left refers to the top color parameter, and the name on the right to the bottom color parameter. In the case of Perpendicular/Parallel black is the front color and white is the side color. Colors can easily be inverted by clicking the arrow button on the right side to swap colors. Viewing the material node it is easy to see how the colors react for the type of falloff you are using.

TIP: When editing your material it is a good idea to have the material node viewable. After setting the colors swap them back and forth make sure the colors are on the correct surface. You can switch the sample type between a Sphere, Cylinder, and Cube sample as well. It’s a quick way to view how your shader will look at different angles and shapes in your model before having to do a full render. You can toggle on and off the node backlight to view with or without multiple light sources. When working with Reflections and/or Refractions turn on the node Background to see how much the surface will be affected by your settings. Testing your shader this can be significantly time saving while developing shaders compared to rendering your entire model.

This is the default Falloff type. The falloff range is based on a 90-degree change in face normal direction. Front faces are facing flat to the view rendered. Any faces 90 degrees from the Front face are the Side faces. The color range would be any face at an angle between the Front and Side faces.

The falloff range is based on a 180-degree change in face normal direction. Towards faces are facing flat to the view rendered. Away faces would be facing the opposite direction 180 degrees, back facing. The color range would be any face at an angle between the Towards and Away faces. This is a much wider range than Perpendicular Parallel. You would never see the set Away color, only the color range from it towards the front of your view rendered

The falloff range is based on adjustments to the Index of Refraction (IOR). Front faces are facing flat to the view rendered. Any faces 90 degrees from the Front face are the Side faces. This type may seem similar to Perpendicular/Parallel except the color range is much tighter pushing the Side color to angled faces just visible from being flat to the view rendered. The color range is on a curve controlled by the Index of Refraction (IOR). Setting the IOR to 1.0 shows only the Front color. The glancing edges visible to the rendered view will be 100% side color above 1.0 value. As the IOR value increase more of the Side color will be visibly blended with the Front color until you reach the maximum 20.0 value. At maximum value the Front color will match the Side color. This is easily viewable while looking at the material node.

This type of fall off is primarily use in the Reflection slot. At default values it results in dim reflections on surfaces facing the view, with much brighter reflections on angled faces, creating highlights like those on the sides of a glass. VrayMTL has a Fresnel reflections box, when checked on, calculates the Reflection as a Fresnel type Falloff map being appied. The Front color defaults to black. If you want a different Front color you will need to apply a actual Falloff map to the Reflection slot. The Reflect color you set becomes the Side color. The Fresnel IOR value by default is locked at 1.6 but can be unlocked to be adjusted.

The falloff range is light dependent. Any faces in shadow will be the Shaded color. Any face in light will be Lit color.

The falloff range is based on distance specified from camera functioning like clipping distance. Color range affects any face in between the two distances. Example uses include reducing aliasing on large terrain objects and controlling the shading in non-photorealistic environments.

Sets the falloff direction relative to the camera (or screen). Color range runs from front to back from the rendered view. Changing object orientation doesn’t affect the falloff map. This map is the default. (See image)

Pick an object whose orientation determines the falloff direction. Click Pick, and then pick an object in the scene. The color range is from the selected object’s center moving away from it.

Works the same as Object direction except you set which axis of the object the color range follows. Changing the orientation of the object changes the falloff direction.

Sets the falloff direction to the world coordinate system axes. Color range will follow the world X,Y, and Z axis. Changing object orientation doesn’t affect the falloff map.

Manipulation of the mix curves gives you direct control over the color range. You can alter how quickly the color shifts between the two options, for how long, and how many times.

As you manipulate the curve the gradient bar underneath the curve indicates how it affects the color range. This is more reliable to view than looking at the node as your falloff may not be in the diffuse slot as it is in the examples.

Usually no alteration is needed for the mix curve for common material types. However, it can come in handy when making more difficult materials like color shifting surfaces such as iridescence, metallics, and pearlescents.