The following light filters are available in C4DtoA:
Arnold "light filters" are arbitrary shaders that can modify a light's output based on distance, position, or other factors. This makes it easy to extend the built-in light sources with additional effects. There are 4 light filters:
Barndoors are opaque moving panels attached to the sides of the light's opening used for additional control over the shape of the light beam.
The gobo filter is used to break up the light beam into an irregular, more natural pattern such as tree leaves, etc.
The light_blocker filter will block out an arbitrary geometrically defined area of a connected light.
The light_decay filter specifies the attenuation ranges of where the light starts and ends.
To create a light filter material you must go to the Material Manager and select Arnold > Light filter and drag and drop it onto the light filter list.
Drag and drop light filter from the Material Browser onto the light filter list