Unity + Leap: Explicit instruction and hand gestures

I have been experimenting a bit with the LEAP and looking at getting objects into the user’s hand. In one of my experiments*, the user holds their hand out flat and a fairy appears. This experiment used explicit instruction written on menus to tell the user what to do.




Explicit instruction worked in that my test users did what I wanted them to - nod and hold their hand out flat. The downside, of course, is that it required them to read instructions which isn’t very immersive or fun. In future experiments, I want to look at implicit instruction, such as having non-player characters perform actions first.

* This demo is now available from the  Leap Motion Gallery.

Notes on getting an object to appear on a user’s hand

Some quick notes on getting the fairy to appear on the user’s hand:

You can find all of the hand models in a scene using:

HandModel[] userHands = handcontroller.GetAllPhysicsHands();

To know if the hand is palm up, you can get the normal vector projecting from the hand relative to the controller, using:

userHands[0].GetPalmNormal()

To know if the hand is open or closed, you can look at the hand’s grab strength. The strength is zero for an open hand, and blends to 1.0 when a grabbing hand pose is recognized.

userHands[0].GetLeapHand().GrabStrength

To know where to place the object, you can get the palm position (relative to the controller), using:

userHands[0].GetPalmPosition()