Light Gobos and IES
Light Gobos and IES profiles are projected textures that help with breaking the perfectly uniform lighting. They are very useful tools to create more interesting and realistic images.
In the Light Properties panel, you can enable the Textures and find controls for the Scale, Position, Opacity and UV repetition of the texture.
The Gobo textures can be found in the library folder set in the Preferences. Categories are created from subfolders present in that library folder.
Important:
Area light Gobos bluriness is affected by its Spread value.
A value of 180 degrees will make the Gobo completely disappear. Reduce its value to make the Gobo visible and sharper.
The IES profiles contain photometric data that include light intensities and 360 degrees information.
If you know that the IES profile you are using has been correctly captured by a light manufacturer with its accurate intensity, it is recommend to press Reset to IES Intensity, which essentially set the Light intensity to 1W.
The IES profiles can be found in the library folder set in the Preferences. Categories are created from subfolders present in that library folder.
IES profiles can be downloaded from manufacturer websites (e.g ARRI Lite 750) or on the free and amazing IES Library.
Included with the add-on is a collection of public domain IES profiles, shared by the Pixar Renderman team.
Note:
IES profile by essence contain the cone angle information. When using IES with Spotlights, it is recommended to increase the Beam Size to 180 to take advantage of the IES.
The properties at the bottom are artistic controls that break physically based rendering but are always useful:
Controls Light visibility to Camera, Diffuse or Glossy Rays
Enables Shadows, and Caustic Shadows
Controls Light Decay using different curves (Quadratic being PBR) and a Falloff Smoothness parameter.
