By default the alt + mouse combination activates the window menu.
The activate the window menu shortcut is currently set to alt+space
The Alt-RMB key combo is used in blender for selecting edge loops.
Install the compizconfig-settings-manager package and run ccsm. At General | General Options | Key bindings | Window Menu
click on Alt<Button3>
, de-select Enabled
and click OK
.
P.S. If this doesn't work, assign a different key to Window Menu
. Thanks to Morichalion.
Fix Alt-drag window move:
With Unity-2D (and now Gnome 3), this is controlled using the
/apps/metacity/general/mouse_button_modifier
GConf key. To disable Alt+Click dragging, run:
gconftool-2 --set /apps/metacity/general/mouse_button_modifier --type string '<Super>'
To re-enable it, run:
gconftool-2 --set /apps/metacity/general/mouse_button_modifier --type string '<Alt>'
Note that this GConf key controls several mouse shortcuts:
Alt+Click: Move windows
Alt+Middle Click: Resize windows
Alt+Right Click: Open a generic window menu
Alt-drag fix for gnome 3:
Here is the new fix:
sudo gconftool-2 --set /org/gnome/desktop/wm/preferences/mouse-button-modifier --type string '<Super>'
If that doesn't work, try this:
install dconf-tools
:
sudo apt-get install dconf-tools
Then run:
dconf-editor
Then navigate to:
org → gnome → desktop → wm → preferences → mouse-button-modifier
Change the value to:
<Super>
Close the dconf-editor
window.
Why this should be necessary when there's a dialogue for system hotkeys under keyboard preferences, is beyond me. Very frustrating having to hunt it down with each new release/update of gnome!
Source: How do I disable window move with alt + left mouse button in GNOME Shell?
Try Shift + Alt + RMB. That was the best solution I could find. You can customize your keys in Blender's user preferences to change loop selection to something else too.