When an attribute that specifies a file path contains a relative path, the path will be considered relative to the current Maya project directory. This path can contain various tokens; this allows the path to dynamically change to reflect the current value of a given token. The following tokens can be used in any file path:
‘$VAR’
The value of the environment variable ‘VAR’ will replace ‘$VAR’ in the path.
‘%VAR%’
The value of the environment variable ‘VAR’ will replace ‘$VAR’ in the path.
‘~’
The value of the HOME environment variable will replace the tilde character.
‘@’
The current frame number will replace the @ character.
‘#’
The current frame number, padded to form a 4 digits number, will replace the # character.
‘{<frame_num_char><operator><operand>}’
Simple expressions to produce a frame number can also be used as a part of the file name. The expression must be enclosed in curly braces. The expression components are:
‘<frame_num_char>’
A character that represents the current frame number. ‘@’ will produce the current frame number, and ‘#’ will produce the same current frame number, padded to form a 4-digits number.
'<operator>’
An arithmetic operator. Valid operators are: ‘+ - * / %’.
‘<operand>’
An integer or floating point number.
For instance, the following are valid frame number expressions:
{#-10}
{@*2.5}
{#%5}
'`MEL command`'
The string enclosed in back quotes is evaluated as a MEL command and gets replaced with the command’s result.
‘<layer>’
This string will be replaced with the currently rendered Maya render layer.
‘<project>’
This string will be replaced with the path to the current Maya project directory.
‘<pass>’
This string will be replaced with the name of the render pass node used for rendering.
‘<shape_name>’
This string will be replaced with the long name of the attached shape. This tag can currently only be used in light attributes nodes.
‘<scene>’
This string will be replaced with the name of the scene.
‘<ext>’
This string will be replaced with the file extension. File extensions are expanded for RIB files, shadow map files, and any file output by a display driver.
‘<camera>’
This string will be replaced with the name of the camera shape being used for rendering.
‘<fragment_set>’
This string will be replaced with the name of the object set used by the RIB fragment being output. It is valid only in render pass rib fragment filename attributes.
‘<aov>’
This string will be replaced with the name of the variable being output in the display. It is valid only in render pass display filename attributes.
‘<output_variable>’
This string is deprecated in favor of ‘<aov>’.