Use Case: Terrain Layer

Summary

• Scope: Terrain Layer
• Level: User Goal
• Actors: App User
• Brief: The user can add, edit, move and delete terrain levels in the terrain layer.

Scenarios

• Precondition: The user has opened the app and has selected the terrain layer.

• Main success scenario:

  • The user successfully sets the base level value for the terrain layer.
  • The user successfully adds, edits, moves and deletes terrain elements in the terrain layer. Terrain elements are, e.g.:
    • Hill: A hill is a terrain element that is higher than the base level.
    • Valley: A valley is a terrain element that is lower than the base level.
  • Terrain elements can be drawn using brushes of different sizes.
  • The height of the terrain elements should be represented by a color gradient.

• Alternative scenario: The user accidentally adds or edits an terrain element in the wrong location and uses the app's undo function to correct the mistake.

• Error scenario: The user attempts to add, move or edit an terrain element but the app is experiencing technical difficulties and is unable to complete the request, displaying an error message.

• Postcondition: The user's map includes the added, edited, moved or deleted terrain elements as desired.

• Non-functional Constraints:

  • Performance: Map sizes with more than 1ha in 10000 raster elements (m²) per year should be usable without noticeable delays and acceptable memory overhead