Linking Lights to Specific Objects

Light linking allows you to light a set of objects while others aren’t or turn off the lights on a set of objects while the others are lit.

Note:  By default the whole scene is lit. In order to light only one specific object, you need first to turn off all the lights for the entire scene (/root/world/geo location).

To link a light to a specific object in the scene, do the following:

1.   Ensure your light is positioned towards the object you want to light.
2.   In the Gaffer object table's Parameters tab, select a light or light filter and click on the Linking sub-tab.

The parameters of the Linking sub-tab are displayed.

3.   Click on the light linking section.

The on and off CEL widgets are displayed.

4.   Shift+middle-click and drag from the /root/world/geo location in the Scene Graph tab to the off CEL widget in the Parameters > Linking sub-tab.

All the lights are turned off in your scene. In the Gaffer object table, the icon "off" appears in the Linking column to indicate you have set up a light link of type "off".

5.   Shift+middle-click and drag from the chosen object location in the Scene Graph tab to the on CEL widget in the Parameters > Linking sub-tab.

The light or light filter selected in the Gaffer object table lights the chosen object only. In the Gaffer object table, the icon "on" appears in the Linking column to indicate you have set up a light link of type "on".

Warning:  If a location is matched by both the on and off CEL expressions, then the on CEL expression overrides the off CEL expression.

Note:  To light several objects, drag as many object locations as needed from the Scene Graph tab to the on CEL widget in the Parameters > Linking sub-tab.

Disabling a Light for Specific Object

To disable a light or light filter, follow the steps below:

1.   In the Gaffer object table's Parameters tab, select the light or light filter you want to disable and click on the Linking sub-tab.

The parameters of the Linking sub-tab are displayed.

2.   Click on the light linking section.

The on and off CEL widgets are displayed.

3.   Shift +middle-click and drag from the chosen object location in the Scene Graph tab to the off CEL widget in the Parameters > Linking sub-tab.

The selected light or light filter for the chosen object location is disabled in your scene. In the Gaffer object table, the icon "off" appears in the Linking column to indicate you have set up a light link of type "off".

Warning:  If a location is matched by both the on and off CEL expressions, then the on CEL expression overrides the off CEL expression.

Note:  For information on how to use the clearUnmatched parameter, see GafferThree.