Project Contact Info

Gerhard Fischer
Center Director

Hal Eden
Project PI

Jack Elston
Research Assistant

University of Colorado
Center for LifeLong Learning & Design
    PitA-Board Project


The PitA-Board.

In the context of the Envisionment and Discovery Collaboratory , we have been working to create an action space that supports more direct interaction of a group of individuals with computational simulations in a face-to-face environment. This has led to the development of the "Participate-in-the-Action (PitA)"-Board.

Initial prototypes of the EDC system were based on a touch-screen technology (SmartTech's SmartBoard) placed in a horizontal orientation, which afforded insights into important aspects of the around-the-table interaction. This revealed several limitations, such as problems with simultaneous interactions and the inability to create interaction behaviors more closely tailored to the objects the user is interacting with.

We are currently using a technology created for electronic chessboards (by DGT Projects, NL) that allows several objects (with embedded transponders) to be tracked simultaneously. Each object can then be given a particular form of behavior by the software system.

To restore the sketching capability that the new system lacks, we are working with electronic pen technology that will allow users to "sketch" their ideas and define objects within a simulation (eBeam).

Areas of Application

We are exploring the use of this technology in numerous contexts where collaborative or participative interaction is a critical aspect of the design process. Possibilities that are being investigated include:

Table of Contents

  • System Architecture
  • Software
  • PitA Board
  • PitA PDA Client
  • Sketching
  • Reflection Space
  • 3D Visualization
  • Project Overview

    System Architecture

    EDC Architecture
    The current system is composed of multiple interacting components. The core of the system, The Pita Simulation (PitaSim), is responsible for querying the PitA Board for piece changes, interpreting user input from the eBeam system, and communicating with any visualization, reflection, or PDA clients.


    PitaSim is constructed using Squeak, a Smalltalk media environment. The use of Squeak allows for the rapid development of a graphical interface, hardware drivers and network connections. Squeak allows for relatively easy creation of simulations, such that real world situations can be modeled by simply defining a few objects and their relationships to each other. Squeak runs on a virtual machine, enabling almost any system to run any one of the PitA servers and clients.


    The current PitA-Board is composed of 4 DGT Projects chessboards linked together and placed in a custom table. Each of the chess pieces contains an RF circuit with a unique signature that allows for 15 different unique inputs per context, and any number of pieces with the same signature. The board is limited in its immediate resolution to the chessboard square size, but provides an advantage over the older models in that several users may input to the simulation simultaneously. An overhead projector linked to the PitA simulation server provides the users with visual feedback on the board, and outlines the grid that a piece may be placed into.

    PitA PDA Client

    In the interest of allowing the technology to be used to support the integration of personal and shared interaction spaces, a PDA client was created to disperse information and voting control to a larger group of participants. As conceived, the PDA client would allow participants to interact with information on an individual basis as well as in the shared interaction space. Each client also has the ability to electronically announce its presence so that the simulation would be aware of a new participant, and be able to send a summary of the simulation thus far so that the user may get caught up.

    A secondary use for the PDA client is for input to the simulation. A user may place a piece or "wand" onto the space in the simulation he or she wishes to modify. That user's PDA will then be granted permission to modify the space or any object occupying that space. Given this scenario, one can imagine one of many uses being for the user to be able to specify certain information about his or her own house. By placing the wand on his or her house, the user might then be prompted to enter information such as number of occupants, cars, etc on his PDA.


    The PitA-Board with sketch pen

    Previous use of SmartTech's SmartBoard supported sketching as well as interaction with the simulation. The sketching functionality was lost when we began to use the DGT Projects chessboard interface. After conducting a few tests of the new interface, several of the participants who had been involved with testing the previous system indicated that the sketching feature was useful and should be re-incorporated into the new system.

    In order to add sketching to the new system, an eBeam electronic whiteboard was added. This tracks the movements of a special pen on the surface and sends the results to an attached computer. In order to avoid adding too much complexity to the user interface, the pen is currently used in a mode that interprets pen movements as mouse movements (thus only one pen can be used at a time). This input provides a very different form of collaboration than the chessboard. Instead of allowing multiple users to make changes at will, the pen interface forces someone to be in charge of making the current changes. In this manner, a new form of social creativity is observed as the users may express their ideas, and then pass control to another user who may add to or modify the existing sketch. We are also exploring how the use of multiple pens might be incorporated.

    The sketching interface involves a color and height picker, a library, and a collection of objects that store the current sketched information. The color picker allows the user to determine the fill color (which can be none for a line) and line color they wish to draw with. The user may also select to change the pen to an eraser. Once the color and height of the sketched object has been determined (height being used in the 3D visualiation mentioned below) the user must still create a new "sketch" before drawing in the action space. Each sketch is a separate object of which a limited number may be stacked upon each other at a time to provide several layers of overlaid sketches. Furthermore each sketch may be saved to and restored from the library object. The library allows for the further option that sketches may created and stored before a presentation and restored to match the context of the conversation later on.

    A further option is available to the user to use a sketch as an actual object in the simulation. By pressing the "make object" button with the pen and selecting a line or filled object from the sketch, the object is then imported to the simulation and can be used as any object, depending on the context of the situation and the desires of the creator of the simulation.

    Reflection Space

    The Reflection Space

    The reflection space is a separate client that connects to the simulation through a TCP link. It is mainly a web client, which takes its cues from the progression of the simulation. As a certain point in the simulation is reached, or a particular piece is used, the reflection space will provide pertinent information. This information can either be pre-stored by an expert in the field, or can be fetched in real time from the web. The idea of the space is to provide useful information to the simulation participants so that they may "reflect" upon the action that they just performed. The space may also be used to keep stats about the simulation such as average bus stop wait time per passenger, percent of land used for particular applications, etc.

    Google Earth client.

    3D Visualization

    The ability to change perspective in an urban planning project is an obvious necessity. Early work on this extension was done using OpenGL. A "visualization server" would connect to the "simulation server" through a TCP socket allowing for the exchange of data during the simulation. Libraries from Coin were used to allow the user to create VRML objects for use in the visualization. This project has been set to the side currently, but is still under consideration for its usefulness in conjunction with a CAVE environment.

    Its replacement is a visualization using Google Earth. By providing KML server objects from the simulation, view control, 3D objects and image overlays can be relayed to a Google Earth client. The current solution employs three separate sockets to handle three of the data streams, each of which is refreshed by the Google Earth client on a periodic basis. By providing this stream separation, the end user can subscribe to the data he is interested in, and can turn off various streams, such as view control, so that he may change the perspective to his personal preference.

    The KML feeds have been separated as follows:

    Immediate 3D visualization is available through a local Google Earth client, which is projected for all participants to observe. Control of the view is done through two designated pieces, and the context of the 2D view. The "camera" for the Google Earth client is centered on the same location as the 2D view, and is positioned according to the location of the designated pieces. The view pieces differ only in view angle, one of which provides a "helicopter" view and the other provides a ground level view. As the 2D view is zoomed in or out, the range of the camera from the center point is decreased or increased respectively, effectively providing the same scaled view as the 2D version.

    PitA-Board visualization using Google Earth.

    All of the sketches, as mentioned before, have an associated height. As can be seen in the sketching image above, the buildings have been sketched into the simulation using the pen. When these are shown in a Google Earth 3D view, the height differences become evident, allowing participants to better visualize the impact of their design conjectures. Note the overlay identical to that used in the action space has been placed beneath the sketched buildings in the Google Earth view.

    Multiple clients can be supported to provide remote meeting capabilities, and further capability can be added by using the PDA client (mentioned above) with a Google Earth client.

    A zoomed-out view.