Add New Attribute to Channel Box
Maya 2012 Tutorial
How to Add Channel Box Attribute in Maya
The Channel Box has ten channels by default. The channels can be controlled with the Graph Editor while animating your object. You may wish to control a specific parameter of an object in the Graph Editor.
This technique illustrates how to create a new channel that is connected to the transparency attribute of your Blinn shader.
Add a polygon sphere to the workspace by choosing Create > Polygon Primitives > Sphere.
Right-click the sphere and choose Assign New Material > Blinn.
With the sphere selected, open the Attribute Editor.
At the top of the panel, choose Attributes, Add Attributes.
In the Add Attributes panel, click the New tab and give your attribute a new name (i.e., objTransp).
Click Float for Data Type. This will allow for numbers with values to the right of the decimal point. Set the Minimum to 0 and Maximum to 1.
Click the OK button to create your new attribute. The next step is to connect your attribute to the object's transparency value.
Select the object and choose Window > General Editors > Connection Editor.
Choose Window >Rendering Editors > Hypershade and click the Graph Materials on Selected Object icon.
Click the object's Blinn node in the Hypershade, then click the Reload Right button in the Connection Editor.
In the Connection Editor, scroll down the left panel and click objTransp.
In the Connection Editor, right panel, open the transparency group and click transparencyR, transparencyG and transparencyB. Close the Connection Editor and Hypershade.
With the object selected, open the Channel Box and note the new attribute named objTransp.
Change the objTransp value from 0 to 0.5 to 1 and the object goes from opaque to transparent. Since the attribute has been added to the Channel Box, you can also access it in the Graph Editor.
Attribute Data Type Values
In this example we selected Float for our Data Type. Depending on your situation, you may wish to used one of the other Data Types.
Vector = 3 Values (i.e., RGB value of a color)
Integer = Whole Numbers
String = Words and/or Numbers
Float = Number (Includes decimal values)
Boolean = True or False (0 or 1)
Enum = Drop Down List
Naming Your Attributes
Stick to camelCase naming conventions when naming your attributes (Step Five). This means no spaces, no starting with numbers, no symbols, etc.