Modify > Add Attribute

Custom attributes are attributes you optionally add and define from the Add Attribute window. Although custom attributes are dynamically added to an object, we refer to them as custom to distinguish them from the built-in dynamic attributes.

Custom attributes have no direct effect on any characteristic of an object in Maya. You can use them to control a combination of other attributes. You might also use a custom attribute as a variable—a place to store a value temporarily to be read by other attributes.

When you add a custom attribute to an object, it appears in the Extra Attributes section of the Attribute Editor (and in the Channel Box, if you make the attribute keyable).

Related topics

Create, edit, or delete custom attributes

Options

Attribute Name: Type the name of the attribute you are adding.
Make Attribute Keyable: Turn this option on to make this attribute keyable. For information about keyable attributes, see Animation.

Data Type

Select the data type for the attribute:

Vector: Creates a vector attribute consisting of three floating point values.
Float: Creates a floating point attribute.
Integer: Creates an integer attribute.
Boolean: Creates an attribute consisting of an on/off turn.
String: Creates a string attribute that accepts alphanumeric entries as data entry, such as a filename.
Enum: Creates an attribute that accepts selections from an “enumerated” or drop-down list.

NoteIf you select Float or Integer, you can also set Numeric Attribute Properties.

Attribute Type

Select a type:

Scalar: Creates a per object attribute that you can set to a single value that applies to every particle in the object. A vector scalar is considered a single value with three numbers. If you select Scalar, you can specify Minimum, Maximum, and Default values for a Float or Integer attribute.
Per Particle (Array): Creates a per particle attribute. You can set this type of attribute to different values for each particle. If you select Per Particle (Array), you can also create a counterpart initial state attribute by turning on Add Initial State Attribute.
Add Initial State Attribute: Turn on to create a corresponding initial state attribute for the added attribute. Without this corresponding attribute, you can’t save a particle object’s current attribute values for initial state usage. You must write a creation expression if you decide to initialize the custom attribute’s value upon rewinding the animation. If you know you’re going to write a creation expression for a custom attribute, you can set Add Initial State Attribute to off when you add the attribute. Otherwise, set Add Initial State Attribute to on whenever you add a custom per particle attribute.

Numeric Attribute Properties: For scalar attributes, Minimum and Maximum set the lowest and highest values you can enter for the attribute in the Attribute Editor or Channel Box. Default sets the default value for the attribute.
Enum Names: When you're adding a new Enum attribute, you need to define the list of acceptable strings. There are two default strings, “Green” and “Blue”, in the Enum Names list that you can change. To change, select Green or Blue and then enter the new string in the New Name text box. To add a new string, click the blank entry below the last list item and type the string in the New Name text box.

The following list of names are reserved internally for (dynamic) shading attributes. You may use these names for custom attributes, but beware they may produce unexpected results in the shading network. For example, during shading the uvCoord value is provided, therefore ignoring your custom uvCoord attribute value.

blobbySurfaceFactor displacement easMask farPointCamera farPointObj farPointWorld filterSize flippedNormal illuminationIndex infoBits lightData lightTable matrixObjectToWorld matrixWorldToObject mediumRefractiveIndex normalCamera numShadingSamples objectId objectType opticalDepth outColor outGlowColor outMatteOpacity outParticleEmission outTransparency particleAge particleAttrArray particleColor particleEmission particleEntryParam particleExitParam particleIncandescence particleLifespan particleOrder particleTransparency particleWeight pixelCenter pixelCoverage pointCamera pointObj pointWorld primitiveId rayDepth rayDirection rayOrigin receiveShadows refPointCamera refPointObj refPointWorld renderState shadowAttenuation tangentUCamera tangentVCamera translucenceDepth triangleNormalCamera uvCoord uvFilterSize vertexCameraOne vertexCameraThree vertexCameraTwo vertexUvOne vertexUvThree vertexUvTwo