Ray
During rendering, the Ray Node can be used to query what type the current calculation ray is. This can be responded to directly in the material to make the material of a sphere glow in the reflection, as in this example, whereas the same material appears normally shaded in the areas directly viewed by the camera.
Note:
This Node is only available when editing a classic Cinema 4D Node Material.
Using this Node we can query the current type of ray being used. For example, will be told whether the ray computes a shadow, represents a reflection, or even a portion of the Global Illumination. The corresponding Boolean signals can be used, for example, to selectively change properties of a material during the different calculation phases of the object. This makes completely new material effects possible that could not be achieved in any other way.