Using tangible objects

Table of Contents

    Introduction

    Tangible interactions are interactions that establish a physical connection between the real-world of a user and the virtual world of a screen. For example, placing an object directly on a screen to pull up information about a specific topic. Tangible objects can have very different shapes, enabling their use across fields such as museums, restaurants, trade shows, and any other business where the use of objects can bring novelty, fun and utility to user interaction.

    NOTE: To work with tangible objects, IntuiFace requires use of the Windows OS and requires the hardware/middleware detecting those objects to communicate using the TUIO protocol.

    How it works

    IntuiFace does not detect or recognize tangible objects, that is the job of hardware/middleware dedicated to tangible object detection. Rather, IntuiFace enables you to react to the presence of these objects. The process is a follows:

    • The hardware / middleware detects one or more tangible objects and identifies them.
    • Information about the detected objects is sent to a Windows PC via the TUIO protocol.
    • IntuiFace's TUIO Interface Asset listens to the TUIO protocol and receives the transferred information
    • IntuiFace raises corresponding triggers of the TUIO Interface Asset - object detected / object moved / object lost - with information about each detected object (unique identifier, X & Y location, orientation)
    • You can use these triggers to call any one or more actions in your IntuiFace experience
    • You can also display the collection of currently detected objects using a data template

    Here is a video of an experience created by our partner Interactive Scape to test their technology with our TUIO Interface Asset.

    About the TUIO protocol

    TUIO (Tangible User Interface Objects) is an open framework defining a common protocol and API for use with multi-touch surfaces that optionally support tangible object recognition. The TUIO protocol enables the transmission of an abstract description of both touch events and tangible object states. You can read more information about this specification on the official TUIO website.

    IntuiFace already supports touch events transmitted by the TUIO protocol as tuio/2Dcur events. To add support for tuio/2Dobj TUIO object events, you have to add the TUIO Interface Asset to your experience and use its properties and triggers to control your experience.

    TUIO Interface Asset

    NOTE: This Interface Asset is still a work in progress. It is provided as beta software in the sample below.

    Properties

    The properties below are read-only, meaning they are only accessible via binding.

    • TUIO Objects: the list of currently detected objects. Each object has the following properties:
      • Session ID: temporary object ID that changes each time it appears / disappears.
      • Symbol ID: unique ID of the object; unlike the Session ID, the Symbol ID is permanent, not temporary
      • X Pos: the X position of the center of the object between 0 and 1. To get the actual X coordinate, multiply the value of this property by the width of your experience, measured in pixels, using the Multiply converter.
      • Y Pos: the Y position of the object between 0 and 1. To get the actual Y coordinate, multiply the value of this property by the height of your experience, measured in pixels, using the Multiply converter.
      • Angle: the rotational angle of the object.

    Triggers

    All of these triggers generate the read only properties mentioned above

    • Object Added: Raised when a new object has been detected
    • Object Removed: Raised when an object has disappeared
    • Object Updated: Raised when a known object has been updated (position / orientation)

    Sample

    You can download a test sample containing the TUIO Interface Asset by clicking this link.