Point to Discover Applications

p2d aims at increasing the usability and acceptance of location based services: Simply point at an object of interest, rather than search for it using text entry or long hierarchical menues on a small screen! User-centered research and development is crucial to make this form of mobile spatial interaction compelling and intuitive.

p2d Restaurant Guide Demo

The p2d project results can be experienced in a real-world showcase scenario: A pointing-enabled mobile restaurant guide for the inner city district of Vienna, Austria - developed in cooperation with Austrian newspaper Falter. Compatibility has been confirmed with the Nokia N70, E61, E65 and N95. The screenshot below shows the application's main user interface.

 

Research Prototypes: Smart Horizons

Apart from the pointing style 'industry demo', we implemented 3D orientation-aware virtual reality representations ("Smart Horizons"). The hardware, platform technology and restaurants are the same as in the pointing demo. The design space explored with our Smart Horizon prototypes can be defined along 3 dimensions:

• Perspective
• Field of View
• Realism

 

We differentiate between three different perspectives to represent the surroundings:

• Vertical View: Shows the actual position from straight above
• Bird's eye View: Visualization of the situation ahead from 45°
• Egocentric View: The situation is shown from the user's position, like in some games

We further differentiate between a frontal and a surround field of view:

• Frontal View: Just buildings in the front are displayed, buildings in the back are invisible
• Surround View: all buildings around are displayed

We also investigate different degrees of realism (decreasing by the abstraction level):

• Billboard: The buildings around are presented as squares
• Block: The building are represented as 3D block shapes
• Texture: Textures are added to the 3D representation of the buildings around

 

Common Features

There are different views to display the buildings around the user. However, all these applications have basic features in common. The p2d symbol on the top right corner of the screen indicates when data is downloaded from the p2d server and processed by the mobile device. This is shown by changing the color of the p2d symbol to white.

 

Application Status Indicators	Nokia N70 Keys	Detailed Information

 

The object directly in front of the user is highlighted by orange color. The status bar on the bottom of the screen displays information about the building which is nearest to the orientation of the mobile device. It tells the nearest restaurant, i.e. the restaurant with the shortest distance, and in the second line the amount of restaurants in this building.

The user can then see more detailed POI information by pressing the selection key. Then she gets a view with further information of all points-of-interest within this building ordered by distance, shortest first. By using the 'up' and 'down' keys the view can be scrolled. If the right soft key or the selection key is pressed, the detailed view closes and the main view of the used application reappears.

Panorama View

The panorama view shows the outline of the buildings in front of the user. The horizontal center of the screen always correlates with the direction the mobile device is held to. If the user moves the mobile device clockwise, the silhouettes move anti-clockwise.

 

Panorama View

 

3D Block View

The 3D Block View represents the surrounded buildings in a three dimensional scene. The visualization of different perspectives is realized by changing the camera position within the szene. The egocentric view has the camera position about two meters above the ground level and looks straight ahead while the vertical view has the camera position several meters above and looks down to the user's position. For the bird's eye view the camera is positioned in the back that the user's position is shown from 45°. The screenshots below show all different types of the 3D Block View.

	Surround	Frontal
Egocentric View	Bird's Eye View

Vertical View

 

The red areas appearing on builings visualize the forefronts of the restaurants inside. The view can be zoomed in and out tilting the device to the front and back.

This 3-dimensional representation allows a set of different application types according to the four factors defined at the beginning of this document. Beside changing the perspective also the field of view can be varied by hiding the background to get the frontal view. While the position of the user is shown as a red cube in the middle of the screen with the surround view, the frontal view does not show the user's position.

 

2D-Map Application

The Map Application differs from the previously introduced applications because there is no geometrical representation of the surrounded buildings. The main view shows a conventional map. The points-of-interest are shown on the map around the user's position and can be selected by the corresponding digit key of the mobile device. Once a point-of-interest is selected by the user, the same detailed view as used above is shown.

Map Application

 

The red star in the center of the screen is the user's actual position. Up to nine points-of-interest are shown to be selected by the user. They are ordered by distance, the nearest point-of-interest first. The application uses four different colors to distinguish between different types of points-of-interest.

• Restaurants: green
• Sightseeing: blue
• Events: purple
• Cinemas: red

3D Textures

The p2d-predecessor project Creative Histories explored spatial awareness in combination with 3D graphic rendering of building textures.

 

Creative Histories

 

 

The table summarizes how the previously defined factors are covered by the different applications.

application	perspective			field of view		realism
	vertical	bird's eye	egocentric	frontal	surround	billboard	block	texture
Panorama
3D Block View
2D Map
Creative Histories