When you paint Ptex maps for attributes, such as Mask or Region Map, to control primitives, Maya creates sub-folders inside the Description for these Ptex files. The data path connecting the maps with Description is specified by the ${DESC} XGen variable. This ensures that all Ptex files are correctly sourced by the Description.
For example, if you modified the GrassDescription Description by
Maya generates the following default data structure for the map files:
See also Control primitives with Ptex maps and Create a Ptex map to control primitives.
XGen uses the same data structure for the Ptex maps generated by XGen modifiers, such as a clumping map created by the Clumping modifier. For example if you added Clumping and AnimWire modifiers to the GrassDescription Description, Maya generates the following default data structure:
See also Modifiers and Create clumping maps.
For a groomable splines Description (called MossDescription for example), Ptex files are created for attributes modified by the Grooming brushes. Maya generates the following default data structure:
See also Create hair and fur using grooming brushes and Groomable splines.