Limiting Lights to Specific Objects
Maya 2012 Tutorial
How to Limit a Light to Specific Objects in Maya
In Maya it is easy to connect lights to specific objects. By default, whenever you add a light to the scene it illuminates all objects in the scene. To limit a light to specific objects, open the Light - Centric or Object - Centric Light Linking panel and set the connections.
Add a text object of the word Spot to the scene by choosing Create > Text. Make sure to include the options.
In the text options enter Spot for the text, set your font and choose Bevel for Type.
Set the Bevel Width and Bevel Depth to 0.02, then set Extrude Distance to 0.2. Click the Create button to add your new text.
Add a polygon plane by choosing Create > Polygon Primitives > Plane.
Using the Channel Box, select the plane and rotate it 90 degrees along the x axis.
While in the Front view, use the Scale tool (r key) scale the plane in the x and y directions so it extends beyond the letters. Use the Move tool (w key) to center the plane to the letters.
In the Top view, use the Move tool (v key) to position the plane in the middle of the letters.
Select the text object and choose Edit > Delete by Type > History. This removes the object's Construction History.
To break the text object into four separate objects, select the text object and choose Mesh > Separate from the Polygons menu set.
Add five spot lights to the scene. Position light one to point at the S, light two points at the p, light three is aimed at the o and light four hits the t. The fifth light should be pointed towards the plane.
Open the Outliner by choosing Window > Outliner and rename the objects, letterS, letterP, letterO, letterT and plane. Rename the lights spot01, spot02, spot03, spot04 and spot05. The light naming should correspond to the object that it is pointing at. In other words, spot01 points at letterS, spot02 points at letterP, etc.
Select the lights one at a time and use the Attribute Editor to assign each light a different color.
Open the Light Linking panel by choosing Window > Relationship Editors > Light Linking > Light - Centric.
In the left column, click spot01. It is currently connected to all the objects shown in blue in the right column. Click on the objects to deselect each of them except letterS.
Repeat the process for the other three letters and the plane. The spot02 light connects to letterP, spot03 connects to letterO, spot04 connects to letterT and spot05 connects to the plane.
Render the scene and note how each light illuminates one of the five objects.
Light Centric vs Object Centric
In the Light Linking menu item you can choose Light Centric or Object Centric (Step Thirteen). If you choose Object Centric it is very similar except the left and right panels are reversed. You can also switch between the modes by selecting Light Centric or Object Centric from the pull-down menu in the upper left corner of the Light Linking panel.