License requirement

The functionality described requires a MANUS Bodypack or a MANUS license key with the Unreal feature enabled.

Interaction framework

This guide will help you make use of the gesture system included in the Unreal Engine plugin.

Retrieve gestures

First open the BP_ManusGlovesPawn_Right/Left_Hand blueprint, and fill the Get Gestures function list. This needs to be done at startup. When starting up your system, the gesture list may be empty. You should wait until the list is filled.

If you want to add or remove gestures during runtime, you need to update the gesture list manually.

Detect gesture threshold

In this example we will use one of the default gestures; Grab. The Gesture ID is retrieved from the previously filled gesture list. Using the Glove ID and Gesture ID, a confidence threshold value needs to be reached. This value ranges from 0-1 (0% no confidence to 100% full confidence).

It is set to 0.8 by default. A value of 0.8 is ideal for most situations.

Warning

A value of 1 or close to one is not recommended, as confidence rarely reaches this high.

Using grab gesture

MANUS uses Unreal’s TryGrabbing system. Once a gesture has been detected and the confidence threshold is reached, the TryGrabbing function is called. If one or more objects are within range, they will be handled by Unreal’s grab system. Objects will then be positioned according to the glove position and rotation.

To fine-tune or offset the position of the object you can add a translation transform to the grabbed object.

Haptic feedback

The interaction framework supports haptic feedback on MANUS Glove devices that support haptics. If the ManusGlovesPawn enters a collision event or grabbable event the haptics is activated and at the end of the event the haptics vibration is returned to 0;