It requires the php-gd extension and “proper” SNMP location formatting on your devices.
Maps are written on a per user basis to html/log (make sure it's writable by the webserver). Upon accessing this module an existing map will be displayed, without any adjustment of the input form.
Graphs are only drawn in PNG and only for the 1st time the map is generated, because they'll be deleted afterwards. This may be a problem, if you wish to save the picture (screenshot always works, though).