Doomsday Manual

--- fs:virtual_directory_mapping [2017-03-15 07:34] – skyjake
+++ fs:virtual_directory_mapping [2017-03-15 07:34] (current) – skyjake
@@ Line 1: / Line 1: @@
+====== Virtual directory mapping ======
+[[version:1.9.0]] introduces //virtual directory mappings// (abbrev. VDM), which allow you
+to make the contents of one directory appear inside another directory
+at runtime.  For example, you could have a directory called
+**MyAuto** with a set of data files somewhere on your hard drive.
+You could map this directory to **Data/<Game>/Auto**, which would
+cause **MyAuto** to behave as though it was an auto-loading
+directory.
+A virtual directory mapping is defined using the //-vdmap// option.
+It takes the source and destination directories as parameters.  For
+example:
+<code>
+-vdmap "D:\Games\MyAuto" "C:\Doomsday\Data\jDoom\Auto"
+</code>
+You can define an unlimited number of virtual directory mappings using
+multiple //-vdmap// options.
+Note, however, that //-vdmap// only affects real files. It does not
+affect virtual files in [[pk3]]s or anywhere else.  The virtual directory
+mappings are tried when all other methods of finding a file have failed. So,
+all real files and [[virtual_file]]s override the VDMs.