Settings → Gestures

Mnemosyne OS can follow your hands through the webcam. You move the canvas, zoom and open apps without the mouse. The rail entry is Gestures. The page subtitle reads Control the canvas by hand, in front of the camera. Everything is off by default.

The page has two tabs: Camera and Board. The app remembers the last tab you opened. Every control saves as soon as you touch it. A slider saves once, when you release it.

For the gestures themselves (pinch, grab, zoom, the pad), read the manual page Hand gestures.

If the settings cannot be read, the page shows Could not read the gesture settings. A failed save shows Could not save: followed by the error, under the camera switch.

Camera tab

Camera

This switch is the permission to use the camera. When on, the camera can be tested.

The switch has two named positions. Screen readers announce it as Allow this app to use the camera.

• Blocked: The camera stays closed for the whole app. This is the default.
• Allowed: Gestures may read the camera, live, on this machine.

This switch is the camera permission of the whole app. With Blocked, no part of Mnemosyne OS can open the camera.

The Camera list picks the device. System default uses the camera your system chooses. Device names appear once the camera has been opened once. Before that, the entries read Camera 1, Camera 2 and so on. Other states:

• No camera found on this machine.
• Could not read the list of cameras.

Test the camera opens a live, mirrored preview. The button then reads Stop. Nothing is recorded. The test needs the switch on Allowed. Otherwise the button is greyed out and the card says Turn the switch on to test. Changing the device stops the test.

A failed test gives one of these reasons:

Message	What to do
The system refused access: see the operating system's camera privacy settings.	Allow the camera in your system's privacy settings.
No camera matched. It may have been unplugged.	Plug the camera back in, or pick another one.
The camera is being used by another application.	Close the other app that holds the camera.
The camera did not answer in time. A common cause: a virtual camera or a stuck driver. Pick another camera or plug it back in.	The system gets 15 seconds to hand over the camera.
The camera could not be opened. The reason was not reported.	The system gave no reason.

The engine

This card shows what the hand tracker is doing right now:

• Off. The switch in the Camera card turns it on.
• Starting the camera and the hand tracker…
• Running. A hand in front of the camera, thumb and index pinched: the plane is grabbed.
• Pinch tracked. Open the fingers to let go.
• Both hands pinched. Spread or bring them together to zoom.
• Pinch resting on an icon. Stay still to open it.
• Scrolling.
• Not running. The hand tracker runs in the main window. The tracker runs in the main window only. Settings opened in another window shows this line.
• The camera could not be opened for tracking. The reason follows.
• The hand tracker could not start. The reason follows.

After one of these two errors, a Try again button appears. The app retries on its own when a camera is plugged back in. The button covers the other cases, such as a driver that recovers or another app that releases the camera.

The card ends with Runs entirely on this machine, model included.

The canvas is locked

Pinch to move and two-hand pinch to zoom act on the endless canvas. The canvas is locked by default. When the camera is allowed and the canvas is locked, this card appears:

Pinch to move and two-hand pinch to zoom act on the canvas. Unlock it to use them.

Unlock the canvas unlocks it.

Practise and tune

Two tiles open the gesture workshop in full screen, with your hands drawn large. Both need the camera on Allowed. Otherwise the card says Allow the camera first, in the Camera card.

• Guided tutorial: Full screen, one gesture after another. The tile also says which pinch setting is in use. It reads In use now: the measured pinch or In use now: the default setting.
• My gestures: A personal pose for an action. You teach your own pose and assign it to an action.

When a measured pinch is in use, the button Back to the default pinch appears. It removes the measurement.

Board tab

On the canvas

Three switches for what the canvas shows. None of them grants the camera.

• Quick button on the canvas: Shows a hand button on the canvas to turn gestures on or off in one click. Off by default. That button writes the same camera permission as the switch on the Camera tab.
• Gesture cheat-sheet: Shows the gesture list on the canvas while the camera runs. Its cross closes it, this switch brings it back. On by default.
• Hands on screen: Draws the hands see-through on the board, where the engine sees them. Helps aiming. Off by default.

With Hands on screen on, two sliders appear:

• Hand opacity, from Faint to Solid: 10 % to 100 %, default 35 %.
• Hand size, from Small to Large: 0.5× to 3×, default 1×.

App pad

Three raised fingers (index, middle, ring) open the pad. Set here the time before a tile opens and the apps shown.

• Time before opening: a slider from Fast to Slow, 0.6 s to 3 s, default 1.4 s. It sets how long your hand rests on a tile before the app opens.
• Apps on the pad (n of total): one checkbox per app of the dock, in the pad's order. Untick an app to take it off the pad. An app you add to the dock later shows up on the pad by default.
• Show all puts every app back. It appears once at least one app is hidden.
• With an empty dock, the card says The dock is empty: apps added to the dock show up here.

Sensitivity

A slider from Slow to Fast, 0.4× to 2.5×, default 1.0×.

Sets how far the canvas travels for a hand movement. At 1.0, crossing the camera frame pans by one screen width.

Reset

Turns the camera off and puts the Gestures module back as on a first launch. Settings, calibration and taught poses are erased.

The hand-tracking model ships inside the app. The reset has no file to delete and nothing to download again.

1. Arm the reset

   Press Reset everything. The button turns red and reads Confirm: erase everything for 5 seconds.

2. Confirm

   Press it again within those 5 seconds. The button reads Resetting….

The reset also forgets where you dropped the quick button. On success the card says Gestures module reset. On failure it says Reset failed: the settings refused the write.

Taught poses cannot come back

The reset erases your measured pinch and every pose taught in My gestures.