Installing and Running Lens in Virtual Andrew

Virtual Andrew is a virtual Windows desktop that you can use to run Lens.
First, visit

	https://virtual.andrew.cmu.edu

A "Log in" link under "Access Virtual Andrew" will allow you to run the client
within your web browser (I believe the native VMware Horizon Client is
available only to faculty).

You'll need to login under your Andrew account, and then you'll be shown a
plain desktop with a "CMU vLab" icon on it, which you should double-click to
connect.  (You'll be asked whether you want to grant permission for full screen
display - up to you.)  Eventually you'll be presented with a Windows 11
desktop.  Note that there's a small tab on the left edge - clicking on this
will let you interact with the Virtual Andrew controller (including logging
out).


INSTALLING LENS (you should only have to do this once)

Within the virtual desktop, open a web browser (e.g., Edge or Chrome), go to

   https://ni.cmu.edu/~plaut/Lens

download Lens-windows.zip, and unzip (extract) it. Inside is a "Lens" folder,
which you should move/drag onto the Desktop.  Do NOT put it into the Sandbox
folder, as this doesn't persist across logins.


RUNNING LENS

Sadly, user-created environment variables do not persist across logins, so you
have to do the following EVERY TIME YOU LOG IN:

Click on the Windows icon in the task bar, search for "Edit environment
variables for your account" and select the result.  Click "New" below the top
panel (User variables) and add the following environment variable (W: is a
drive alias for your own files):

  name:  LENSDIR
  value: W:\Desktop\Lens

Also edit the existing "Path" variable in the same panel and add a new line:

  %LENSDIR%\Bin

Now, to run Lens, open a Command Prompt (click the Windows icon and search for
it), navigate to the folder containing your network files, and run "lens". (For
example, to get to a "HW1" folder inside the Lens folder, type "W:" first and
then "cd Desktop\Lens\HW1".)  If you try to run Lens but it says it's not
recognized as a command, chances are you forgot to create the LENSDIR variable
(or forgot to edit the Path variable). NOTE: If you start lens by
double-clicking on the "lens" executable in Lens\Bin, lens will start but you
won't be able to access any files due to read protections.

You can put folders for homeworks and such in the Lens folder and they will
also persist across login sessions.  However, to be safe, you should ALWAYS
BACK-UP ALL RELEVANT FILES to your computer at the end of each session (see
below).

When you're finished (and have backed up your files), click on the side tab
and select "Log Out" from the menu in the upper right (for Virtual Andrew).


TRANSFERRING FILES TO/FROM YOUR COMPUTER

The most convenient way to transfer files is to open a browser inside the
virtual desktop, login to a cloud storage service (e.g., Box or Google Drive),
and use that to upload/download files.

The Virtual Andrew controller has a "File Transfer Panel" tool (at the top) that
can be used to upload files (from your computer into your Documents folder of
the virtual desktop), but it doesn't support downloading from the virtual
desktop to your local machine.

David Plaut
13 Jan 2025