Leap Motion's Interaction Engine Promises To Improve Hand-Grabbing VR Physics

Leap Motion announced a new module for its Unity Core Assets package. The module is called the Interaction Engine, and it's designed to replace the game’s standard physics engine when you interact with virtual objects with your hands and the Leap Motion controller.

The Leap Motion controller has been around for a couple of years now. Last year we took a look at the peripheral in the context of virtual reality, and we noted that it still needed some work. Earlier this year, Leap Motion released the Orion update, which features improved tracking performance. The company made the Orion platform available for developers immediately, but the bundled demo that showed off the new tracking algorithms also included the Interaction Engine module, which improved the ability to grab small objects within the environment.

Standard game physics engines work great for traditional games, but virtual objects don’t like to interact with virtual hands with those physics models. In many cases, if you reach out for an object, it will jump away from you because it’s not designed to allow for virtual fingers to pass through them. Without haptic feedback, closing your hand too tightly or reaching too far when grasping for an object is inevitable. The Interaction Engine is designed to solve precisely these problems.

The Interaction Engine is built on a layer that sits between the Unity engine and the Leap Motion hand tracking data and was designed to be as easy as possible to deploy. The module alters the way small objects interact with your hands by making their structure elastic. Rather than desperately trying to figure out how not to let your fingers pass through the object, Interaction Engine injects and an alternate set of physics instructions that activate when your hands are “embedded inside a virtual object.” 

The Interaction Engine can also be used to improve your ability to stack objects properly, and it even offers improvements for throwing mechanics. Leap Motion said that you can also customize the Interaction Engine’s throwing physics.

The Interaction Engine is tuned to work with cubes and spheres between 1-2 inches in size. Leap Motion said other objects “may have different results,” and the company is looking for feedback from developers about how good Interaction Engine works with game objects of different shapes and sizes so that it can improve the experience over time.

The early access beta program for Leap Motion’s Interaction Engine starts today. Developers are encouraged to try it out for themselves. You can find the Leap Motion Unity Core Assets package, which includes the Interaction Engine Module, at Leap Motion’s developer hub. For documentation on the release and additional support, see the Leap Motion community forums.