Ai UserData Shaders
| Further Reading |
|---|
| See Shading in the Arnold User Guide for the full shader documentation. |
You can add attributes to shape nodes in Maya, and MtoA will export those extra attributes as user data in the Arnold shape nodes. When the scene is translated to Arnold, attributes are not exported automatically. They must first be added as a Maya 'attribute' to the geometry, where it is visible in the 'Extra Attributes'. On export, MtoA translates them into user attributes on the Arnold geometry. If for example, an attribute is named in *user_data_rgb,* but the input passed is an integer, then it will still work and just convert the integer to float and pass it to each of the R, G & B values.
It is also possible to read user data fields from volumetric shapes, allowing things like per-particle user data on volumetric spherical point clouds to affect the result of volumetric shading.
The following examples show you how to use the 'UserData' nodes:
User Data Bool
Bool Attr Name
...
Default Value
...
User Data Color
Color Attr Name
Read RGB color from shape user data, at the current shading point on the surface.
Default Value
Output value to use if user data with the specified name is not available.
User Data Float
Float Attr Name
Read float value from shape user data , at the current shading point on the surface.
Default Value
Output value to use if user data with the specified name is not available.
User Data Int!
Int Attr Name
Read integer value from shape user data , at the current shading point on the surface.
Default Value
Output value to use if user data with the specified name is not available.
User Data Pnt2
Pnt 2Attr Name
...
Default Value
...
User Data String
String Attr Name
Reads the string from shape user data .
Default Value
Output value to use if user data with the specified name is not available.
User Data Vector
Vector Attr Name
...