Use Cases

Release 1

UC1: Player Movement

ID: UC1
Name: Player Movement
Description: Navigating around the world using the mouse and keyboard
Area: In-Game
Actors: Player

Preconditions:

• Player has loaded a world

Steps:

• Player presses W or ⬆ on the keyboard
• System moves the camera forwards
• Player presses A or ⬅ on the keyboard
• System moves the camera to the left
• Player presses S or ⬇ on the keyboard
• System moves the camera backwards
• Player presses D or ⮕ on the keyboard
• System moves the camera to the right
• Player presses SPACE on the keyboard while on the ground
• System moves the camera up
• Player moves the mouse
• System moves the camera angle

Post-conditions: n/a

UC2: Spectator Mode

ID: UC2
Name: Spectator Mode
Description: Disabling player-block collisions and gravity, allowing the player to move freely in the world
Area: In-Game
Actors: Player

Preconditions:

• Player has loaded a world

Steps:

• Player presses G on the keyboard
• System enables spectator mode
• Player moves around (→ UC1)
• System does not enforce player-block collisions and gravity
• Player presses SPACE on the keyboard
• System moves camera up
• Player presses LEFT SHIFT on the keyboard
• System moves camera down
• Player presses G on the keyboard again
• System disables spectator mode

Post-conditions: n/a

UC3: Selecting a Block Type

ID: UC3
Name: Selecting a Block Type
Description: Selecting a block type to place in the world (→ UC4)
Area: In-Game
Actors: Player

Preconditions:

• Player has loaded a world

Steps:

• Player presses one of 1, 2, 3, 4, 5, 6, 7, 8, 9 on the keyboard
• System selects the block type corresponding to the pressed key
  • 1 selects the block type “Grass”
  • 2 selects the block type “Dirt”
  • 3 selects the block type “Cobblestone”
  • 4 selects the block type “Oak Log”
  • 5 selects the block type “Spruce Log”
  • 6 selects the block type “Birch Log”
  • 7 selects the block type “Oak Leaves”
  • 8 selects the block type “Spruce Leaves”
  • 9 selects the block type “Birch Leaves”

Post-conditions:

• The block type corresponding to the pressed key is selected

UC4: Placing Blocks

ID: UC4
Name: Placing Blocks
Description: Placing a block at the position the camera is pointing at
Area: In-Game
Actors: Player

Preconditions:

• Player has loaded a world

Steps:

• Player presses the right mouse button
• System places a block of the type selected by the player (→ UC3) or a default of “Grass” at the position the camera is pointing at
  • Exception Flow: The camera does not point at an existing block or the block is more than 5 blocks from the camera away
    • Do nothing

Post-conditions: n/a

UC5: Destroying Blocks

ID: UC5
Name: Destroying Blocks
Description: Destroying the block at the position the camera is pointing at
Area: In-Game
Actors: Player

Preconditions:

• Player has loaded a world

Steps:

• Player presses the left mouse button
• System destroys the block at the position the camera is pointing at
  • Exception Flow: The camera does not point at an existing block or the block is more than 5 blocks from the camera away
    • Do nothing

Post-conditions: n/a

UC6v1: Starting the Game

ID: UC6 (v1)
Name: Starting the Game
Description: Creates a new world with procedurally generated blocks with a fixed size of 16 × 16 chunks (256 × 256 blocks)
Area: In-Game
Actors: Player

Preconditions: n/a

Steps:

• Player starts the game
• System generates a new world with a fixed size of 16 × 16 chunks (256 × 256 blocks)
• System shows the game

Post-conditions:

• Player has loaded a world

Release 2

UC6v2: Creating a New World

ID: UC6 (v2)
Name: Creating a New World
Description: Creates a new world with procedurally generated blocks with a fixed size of 16 × 16 chunks (256 × 256 blocks)
Area: Game UI
Actors: Player

Preconditions: n/a

Steps:

• Player starts the game
• System shows main menu
• Player presses “Singleplayer” button
• System shows singleplayer world selection menu
• Player presses “Create New World” button
• System shows world creation form
• Player enters a world name
• Player optionally enters a seed
• Player presses “Create World” button
• System generates a new world with a fixed size of 16 × 16 chunks (256 × 256 blocks)
  • Exception Flow: Name input field is empty
    • System shows an error message
    • Continue with “Player enters a world name”
  • Exception Flow: There exists already a world with the entered name
    • System shows an error message
    • Continue with “Player enters a world name”
  • Exception Flow: Seed input field is empty
    • A randomly generated number is used as the seed
    • Continue with “System generates a new world…”
• System shows the game

Post-conditions:

• Player has at least one saved world
• Player has loaded a world

UC7: Loading a Saved World

ID: UC7
Name: Loading a Saved World
Description: Loads a world previously saved to disk
Area: Game UI
Actors: Player

Preconditions:

• Player has at least one saved world

Steps:

• Player starts the game
• System shows main menu
• Player presses “Singleplayer” button
• System shows singleplayer world selection menu
• Player selects a world from the list
• System highlights the selected world
• Player presses “Play Selected World” button
• System loads the selected world from disk
• System shows the game

Post-conditions:

• Player has loaded a world

UC8: Saving and Quitting the Loaded World

ID: UC8
Name: Saving and Quitting the Loaded World
Description: Saves the world that is currently played to disk and quits to the main menu
Area: Game UI
Actors: Player

Preconditions:

• Player has loaded a world

Steps:

• Player presses ESC on the keyboard
• System shows pause menu
• Player presses “Save and Quit to Menu”
• Systems saves world data to disk
• System shows main menu

Post-conditions: n/a

UC9: Exiting the Pause Menu

ID: UC9
Name: Exiting the Pause Menu
Description: Going back from the pause menu to the game
Area: Game UI
Actors: Player

Preconditions:

• Player has loaded a world
• Player is in the pause menu

Steps:

• Player presses ESC on the keyboard or presses the “Back to Game” button
• System shows the game

Post-conditions: n/a

UC10: Quitting the Game

ID: UC10
Name: Quitting the Game
Description: Quitting the game from the main menu
Area: Game UI
Actors: Player

Preconditions:

• Player is in the main menu

Steps:

• Player presses ESC on the keyboard or presses the “Quit Game” button
• System exits

Post-conditions: n/a

UC11: Aiming with the Crosshair

ID: UC11
Name: Aiming with the Crosshair
Description: A crosshair is shown at the center of the screen to indicate where the player is aiming at
Area: In-game
Actors: Player

Preconditions:

• Player has loaded a world

Steps:

• System displays a crosshair at the center of the screen
• Player moves the camera to look around the world (→ UC1)

Post-conditions: n/a

NFR1: Performance

ID: NFR1
Goal: The system should run with high performance
Area: In-Game

Questions / Metrics:

• How fast is the rendering process?
  • Average frames per second on the deployment server
    • Minimum: 20 FPS
    • Target: 60 FPS
  • Max frame time (no frames slower than) on the deployment server
    • Minimum: 60 ms
    • Target: 20 ms
• How many invisible blocks are rendered?
  • Percent of blocks rendered outside the FOV from all rendered blocks
    • Minimum: 30 %
    • Target: 15 %
• How much memory does the game allocate?
  • Amount of allocated RAM after 15 minutes of playing
    • Minimum: 1 GB
    • Target: 600 MB
  • Amount of allocated VRAM after 15 minutes of playing
    • Minimum: 300 MB
    • Target: 150 MB
• How responsive is the system?
  • Input latency
    • Minimum: 40 ms
    • Target: 20 ms

NFR2: Graphics Quality

ID: NFR2
Goal: The graphics quality should be good
Area: In-Game

Questions / Metrics:

• How do players rate the visual quality of distant textures?
  • Mean Opinion Score from 5 testers comparing mipmapped vs. non-mipmapped clips on a scale from 1 to 5
    • Minimum: 3.5
    • Target: 4.0
  • A/B preference: Preference of testers preferring the version with mipmapping
    • Minimum: 80 %
    • Target: 90 %

Release 3

UC6v3: Creating a New World

ID: UC6 (v3)
Name: Creating a New World
Description: Creates a new world and generates an initial area of 16 × 16 chunks (256 × 256 blocks)
Area: Game UI
Actors: Player

Preconditions:

• Player is logged in
• Player is in the main menu

Steps:

• Player presses “Singleplayer” button
• System shows singleplayer world selection menu
• Player presses “Create New World” button
• System shows world creation form
• Player enters a world name and optionally a seed
• Player presses “Create World” button
• System creates a new world and generates an initial area of 16 × 16 chunks (256 × 256 blocks)
  • Exception Flow: Name input field is empty
    • System shows an error message
    • Continue with “Player enters a world name”
  • Exception Flow: There exists already a world with the entered name
    • System shows an error message
    • Continue with “Player enters a world name”
  • Exception Flow: Seed input field is empty
    • A randomly generated number is used as the seed
    • Continue with “System generates a new world”

Post-conditions:

• Player has at least one saved world
• Player has loaded a world

UC11: Infinite Procedural Generation

ID: UC11
Name: Infinite Procedural Generation
Description: While moving around the world, new chunks are generated
Area: In-Game
Actors: Player

Preconditions:

• Player has loaded a world

Steps:

• Player moves around in the world (→ UC1)
• System generates new chunks with the same seed used for the initial generation

Post-conditions: n/a

UC12: Coordinate Overlay

ID: UC12
Name: Coordinate Overlay
Description: Show an overlay with the coordinates of the camera in the top left corner
Area: In-Game
Actors: Player

Preconditions:

• Player has loaded a world

Steps:

• System shows an overlay with the coordinates of the camera in the top left corner
• Player moves around in the world (→ UC1)
• System updates the overlay with the new coordinates of the camera

Post-conditions: n/a

UC13: Deleting a Saved World

ID: UC13
Name: Deleting a Saved World
Description: Deletes a world previously saved to disk
Area: Game UI
Actors: Player

Preconditions:

• Player is in the main menu
• Player has at least one saved world

Steps:

• Player presses “Singleplayer” button
• System shows singleplayer world selection menu
• Player selects a world from the list
• System highlights the selected world
• Player presses “Delete Selected World” button
• System deletes the selected world from disk
• System shows the game

Post-conditions: n/a

Further Development

UC14: Signing up for a Player Account

ID: UC13
Name: Signing up for a Player Account
Description: Allowing the player to create an account with a unique player name
Area: Game UI
Actors: Player

Preconditions: n/a

Steps:

• Player starts the game
• System shows login screen
• Player presses “I don’t have an account” link
• System shows signup screen
• Player enters a player name
• Player enters a password
  • Misuse Flow: Another person sees the entered password and memorizes it
    • Capture Point: The password is hidden
    • Capture Point: Data is transmitted over an encrypted channel
• Player presses “Create Account” button
• System creates account
  • Exception Flow: Name input field is empty or too long
    • System shows an error message
    • Continue with “Player enters a player name”
  • Exception Flow: A player with the specified name already exists
    • System show an error message
    • Continue with “Player enters a player name”
  • Exception Flow: Password input field is empty or too short
    • System shows an error message
    • Continue with “Player enters a password”
• System shows main menu screen

Post-conditions:

• Player has an account
• Player is logged in
• Player is in the main menu

UC15: Logging in to a Player Account

ID: UC14
Name: Logging in to a Player Account
Description: Allowing the player to log in to their player account
Area: Game UI
Actors: Player

Preconditions:

• Player has an account

Steps:

• Player starts the game
• System shows login screen
• Player enters their player name
• Player enters their password
  • Misuse Flow: Another person sees the entered password and memorizes it
    • Capture Point: The password is hidden
    • Capture Point: Data is transmitted over an encrypted channel
• Player presses “Log in” button
• System authenticates the player
  • Exception Flow: A player with the specified name does not exist or the password was not correct
    • System shows an error message
    • Continue with “Player enters their player name”
• System shows main menu screen

Post-conditions:

• Player is logged in
• Player is in the main menu

UC16: Changing the Player Name

ID: UC15
Name: Changing the Player Name
Description: Changing the player name
Area: Game UI
Actors: Player

Preconditions:

• Player is logged in
• Player is in the main menu

Steps:

• Player presses “Account” button
• System shows account setting screen
• Player presses “Change Player Name” button
• System shows change player name screen
• Player enters a player name
• Player presses “Change Player Name” button
• System updates the name of the player
  • Exception Flow: Name input field is empty or too long
    • System shows an error message
    • Continue with “Player enters a player name”
  • Exception Flow: A player with the specified name already exists
    • System show an error message
    • Continue with “Player enters a player name”
• System shows main menu screen

Post-conditions: n/a

UC17: Changing the Password

ID: UC17
Name: Changing the Password
Description: Changing the password
Area: Game UI
Actors: Player

Preconditions:

• Player is logged in
• Player is in the main menu

Steps:

• Player presses “Account” button
• System shows account setting screen
• Player presses “Change Password” button
• System shows change password screen
• Player enters their old password
• Player enters a new password
  • Misuse Flow: Another person sees the entered password and memorizes it
    • Capture Point: The password is hidden
    • Capture Point: Data is transmitted over an encrypted channel
• Player presses “Change Password” button
• System updates the password of the player
  • Exception Flow: Password input field is empty or too short
    • System shows an error message
    • Continue with “Player enters a password”
  • Exception Flow: The old password was not correct
    • System shows an error message
    • Continue with “Player enters their old password”
• System shows main menu screen

Post-conditions: n/a

UC18: Deleting the Player Account

ID: UC18
Name: Deleting the Player Account
Description: Deleting the player account
Area: Game UI
Actors: Player

Preconditions:

• Player is logged in
• Player is in the main menu

Steps:

• Player presses “Account” button
• System shows account setting screen
• Player presses “Delete this Account” button
• System shows delete account screen
• Player enters their old password
• Player presses “Yes”
• System deletes the account of the player
  • Exception Flow: The old password was not correct
    • System shows an error message
    • Continue with “Player enters their old password”
• System shows login screen

Post-conditions:

• Player is not logged in

UC19: Enabling Multiplayer for a World

ID: UC19
Name: Enabling Multiplayer for a World
Description: Opening the world for other players to join until the host player quits the world or disables multiplayer
Area: Game UI
Actors: Player

Preconditions:

• Player has loaded a world
• Multiplayer is not enabled for the world

Steps:

• Player presses ESC on the keyboard
• System shows pause menu
• Player presses “Enable Multiplayer” button
• System shows multiplayer options screen with default configuration (random port, empty blocklist)
• (optional) Player enters a port
• (optional) Player manages access list (includes UC21)
• Player presses “Enable Multiplayer for this World” button
• System enables multiplayer for the world
  • Exception Flow: Port input is not a valid port
    • System shows an error message
    • Continue with step “Player enters a port”
  • Exception Flow: Port is already in use
    • System shows an error message
    • Continue with step “Player enters a port”
• System shows the game

Post-conditions:

• Multiplayer is enabled for the world

UC20: Changing Multiplayer Options

ID: UC20
Name: Changing Multiplayer Options
Description: Changing options for a world with multiplayer enabled
Area: Game UI
Actors: Player

Preconditions:

• Player has loaded a world
• Multiplayer is enabled for the world
• Player is the host of the multiplayer world

Steps:

• Player presses ESC on the keyboard
• System shows pause menu
• Player presses “Multiplayer Options” button
• System shows multiplayer options screen
• (optional) Player manages access list (includes UC21)
• Player presses “Apply & Back to Game” button
• System applies changed options
  • Exception Flow: A Player who was denied access has already joined the world
    • System removes player from the world
    • Continue with step “System shows the game”
• System shows the game

Post-conditions: n/a

UC21: Managing Multiplayer Access List

ID: UC21
Name: Managing Multiplayer Access List
Description: Changing the multiplayer to allowlist / blocklist mode and adding / removing players from the access list
Area: Game UI
Actors: Player

Preconditions:

• Player is in the multiplayer options screen

Steps:

• Player presses “Allowlist” or “Blocklist” button
• System changes the multiplayer access mode
• Player enters a player name to add to the list
• Player presses “Allow to join this world” / “Block from joining this world” button (depending on the selected access mode)
• System adds the player with the specified name to the list
  • Exception Flow: The specified name is the name of the player hosting the multiplayer world
    • System shows an error message
    • Continue with step “Player enters a player name to add to the list”
  • Exception Flow: A player with the specified name does not exist
    • System shows an error message
    • Continue with step “Player enters a player name to add to the list”
• Player selects a name from the list
• System highlights the selected player
• Player presses “Remove from list” button
• System removes the player from the list

Post-conditions: n/a

UC22: Joining a Multiplayer World

ID: UC22
Name: Joining a Multiplayer World
Description: Joining a multiplayer world opened by another player
Area: Game UI
Actors: Player

Preconditions:

• Player is in the main menu

Steps:

• Player presses “Multiplayer” button
• System shows multiplayer selection screen
• Player enters the address of the multiplayer world
• Player presses “Join Multiplayer” button
• System joins the multiplayer world
  • Exception Flow: The address is invalid or there is no world hosted on the address
    • System shows an error message
    • Continue with “Player enters the address of the multiplayer world”
  • Exception Flow: The player’s access was denied by the player hosting the multiplayer world
    • System show an error message
    • Continue with “Player enters the address of the multiplayer world”
• System shows the game

Post-conditions:

• Player has loaded a world