README.md

Construction Mode - Gesture Ver.

Author : Yuan Yao
Last Update : 2016.09.11

I. Introduction :

This is the gesture version of the game Construction Mode. It aims to help people practice their spatial reasoning skills. We used Leap Motion to detect the movement of user's hands and created a set of gestures as the input of the game.
You can check the demo to briefly see how it works.

II. Operating Guide :

The set of gestures can be separated into two class : one hand and two hands.

Attention : The one hand class gesture ++only can be detected when there is only one hand on the screen++, similarly two hands class gesture ++only can be detected when two hands appear on the screen++. The reason is because of the codes(HandController.cs) :

protected virtual void FixedUpdate()
{
    if (frame.Hands.Count == 2){
        ...
    }
    else if (frame.Hands.Count == 1){
        ...
    }
    else{
        ...
    }
}

Now here are the list of all the gestures.

One Hand :

1. Swipe Gesture

Swipe your hand to rotate the object. The three direction are corresponding to three DoF of rotation. And the coordinate system is Unity's coordinate system. The difference between Leap Motion coordinate system and Unity system can seen as follows.
Leap Motion :

Unity :

• Up or Down ( Swipe along with Y-axis ) : Clockwise ( direction > 0 ) or Counterclockwise ( direction < 0 ) rotation around Z-axis.

• Left or Right ( Swipe along with X-axis ) : Clockwise ( direction < 0 ) or Counterclockwise ( direction > 0 ) rotation around Y-axis.

• Forward or Backward ( Swipe along with Z-axis ) : Clockwise ( direction < 0 ) or Counterclockwise ( direction > 0 ) rotation around X-axis.

Attention : ++All the swipe gestures should be parallel to the corresponding axis++ because of such codes :

if (
    (
    Math.Abs(swipe_direction_world.x) > 3 * Math.Abs(swipe_direction_world.y)
    ) && (
    Math.Abs(swipe_direction_world.x) > 3 * Math.Abs(swipe_direction_world.z)
    )
)

This condition sentence check whether your hand's movement is along the X-axis, therefore if the component of the movement on Y-axis or Z-axis is more that 1/3 of the component of that on X-axis, the movement won't be regarded as an X-axis swipe gesture. The swipe gestures on other directions are the same. To make it more generalizable, you can replace 3 with 2 or 1.5 .

2. Fist Gesture

Make your hand become a feast and the object can move as long as your feast move.

Attention : Make sure Leap Motion can ++see all of your fingers++, for example do not do like this :

Two Hands :

1. Left Hand Fist Gesture

Make your left become a fist then you will enter selection mode which will call the menu.

The actual result is as follow :

Attention : To keep this menu, you should always keep your left hand as a fist and both of your two hands be presented on the screen.

2. Left Hand Fist Right Hand Swipe Gesture

Keep left hand as a fist and swipe your right hand, you will be able to make different objects highlighted.

The actual result is as follow :

3. Grab Gesture

Keep your two hands' fingers blending and move in the x-y plane, then the view will change as long as you move.

The actual result is as follow :

Attention : Grab gesture is different from fist, which means you should not blend your fingers too much. Also the directions of the movements of your hands should be the same.