HOUDINI_GALLERY_PATH :="@/gallery"
Specifies the search path to the directory that contains the gallery
files. If this variable is not set, Houdini looks in the gallery
subdirectories of the standard search path, which includes
$HFS/houdini/gallery/, for example. Gallery files specify the
predefined parameter values for any node type, much like the
presets. However, they are used predominantly for defining shaders
and materials.
Default path: '@/gallery'
Where @ is replaced with HOUDINI_PATH
Directories searched (in order) are:
1)"$HFS/houdini/gallery"