COMP4002/GAM Games - Topologies

•  Player archetypes

•  Single player

•   Pre-defined challenges, “campaigns”, AI controlled opponents

•  Multiplayer

•   Interaction with other players forms a key challenge of the game play

•    People are “better” than AI systems

•    Less predictable, more complex, more interesting

•    Playing with people provides a social element

•    Larger environments supporting a greater variety of characters

•    Potentially supporting an economy or trading between players

•  Modes

•  Transient

•   Ad-hoc, short-lived sessions

•   Easy to “host” a game

•   Quake, Team Fortress, Overwatch

•  Persistent

•   A central authority maintains a persistent world

•   World of Warcraft

Local Multiplayer

•  Interaction between multiple players

•   Attempt based, “hot-seat”

•   Concurrent

•  Shared (full) screen

• Only render one view/camera perspective for all players

•    Efficient, enables synchronous communication through play

•   Complete playfield visibility

•    Fit all players on the same screen

•   Adaptive

•   Zoom to keep everyone on the screen

•    Emergent gameplay: - camera affects players

•     Restrict movement, player-funneling

•     Kill the player if they’re off the screen for too long

•  Split screen

•   Render a different view for each player

•    Double/quadruple the rendering overhead

•   Shrink the view, change the aspect ratio

•   Emergent gameplay, cheating

Networked / Online Game Play

• Players are physically separate

• Communicating sufficient information to maintain a perceptually shared

reality, while minimising both bandwidth use and perceived violations of the integrity of the simulation / fiction

• User input -> model, model -> client view for rendering

• Considerations

•  Topology – arrangement of key components

• Nature of the communication / “ netcode”

Topologies

• Where is the “game”?

•  An authoritative model somewhere (game state)

•  Possible topologies

•  Primary and secondary

•  One player’s game takes responsibility for the model

•   Authoritative client-host

•  Dynamic peer-to-peer

•  Relay server

•   A server to simply mediate communication between clients

•  Dedicated server and clients

• Dedicated software / machine is responsible for the model

•  Multiple players, local network, internet

•  True peer-to-peer

•  Shared responsibility for the model

•   Difficult to scale, verify