4.3 Data flow diagrams

The following diagrams (figures 2-5) indicate the data flows in the system, showing how interaction by the user causes changes to be made in the view of the model presented on the screen.

Figure 2: Initial level view of system

Figure 3: First level view of system

Figure 4: Procedure 2: rendering of the model

Figure 5: Procedure 2.2: Required View of Model Calculated

Data dictionary

Procedures

• 0. Production of Interactive Virtual Model = the overall procedure which allows a user to interact with the three-dimensional model of the tomb
• 1. Interaction with model = the interaction the user undertakes with the model by using the mouse and viewing the model on the screen
• 2. Rendering of model = the process by which the computer generates the data necessary to present a view of the model on the screen
• 2.1 Files accessed = the process by which software calls the required stored files to create the tomb model
• 2.2 Required view of model calculated = the process by which the software interprets all the data given about the model and the user input given to produce a relevant view of it.
• 2.2.1 Preliminary view created = the process by which the first view of the tomb is created from the stored data, recreated when there is no input from the user
• 2.2.2 Change to view calculated = the process where the model interprets the effect user input would have on the current view of the model
• 2.2.3 Changes made if necessary = the process where the first view of the model is adjusted to accommodate user interaction.
• 3. Display of model = The process in which the data of the model is displayed on the screen

Data stores

• D1= The repository in computer memory for all software and world files.

Data flow

1. Activation procedure = the procedure by which the institution activated the system and produces the first view of the tomb model
2. Choice of action = the decision to move in any direction by the user by using the mouse
3. Choice of tool = the choice the user makes to specify which navigational tool is currently employed
4. Model data = the digital data regarding the model required to produce one view
5. Model information = the site and sounds of the model which are imparted to the viewer
6. No input = the signal given when the user does not interact with the system
7. User choices = the instructions the user gives the system via the mouse
8. Stored information = all the digitally stored information required to render the model (including software)
9. View of model = the data needed to produce a view of the model on the screen

External entities

• Museum = the institution which holds the computer system
• User = a museum visitor

© Internet Archaeology URL: http://intarch.ac.uk/journal/issue7/terras/dfd.htm
Last updated: Mon Nov 29 1999