XGen comes with samples of Alembic-based geometry and material files that you can add to your scene. These files are located in the archive folder in the Maya installation directory. For example:
C:\Program Files\Autodesk\<Maya version>\plug-ins\xgen\presets\archives.
In this section, you add grass clumps to a vegetation landscape.
In this example, the archive objects are added to a sculpted polygon plane.
The mesh is now bound to the Description. Use the Add or Move Guides tool to place the guides on the mesh surface.
 to select the 
	 Add or Move Guides 
	  tool.
 to select the 
	 Add or Move Guides 
	  tool. 
  
The guides for archive primitives display on the mesh as orange cubes. You can now specify which archived geometry you want to instance on the mesh.
For example:
C:\Program Files\Autodesk\<Mayaversion>\plug-ins\xgen\presets\archives
or
C:\Users\username\Documents\xgen\archives.
The grass clump geometry previews in the scene. In the Archive Files section, notice that a thumbnail image represents the grass clump geometry.