Transcript Slides for Erik's talk

Tools for Game Developmet
Erik Harpstead
Carnegie Mellon University
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Game Development is Hard
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Challenges in Game Development
• Rapidly shifting design requirements
• Multi-platform development
• Integration of many different forms of media (sound,
music, art, modeling)
• Highly interdisciplinary teams
• The demand for novelty
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Three Routes for Development
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Three Routes
• Roll your own engine
• Use a Framework
• Use an off-the-shelf engine
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Rolling Your Own Engine
• Surprisingly common
• Special game mechanics require custom software
architectures
• Existing tools are too restrictive for rapid design changes
• Using other people’s tools is a cop-out
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Using a Framework
• Usually provide basic utilities and primitives
• Commonly built around a state machine in a loop
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Using a Framework
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Using a Framework
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Using a Framework
• Other Common Components:
– Rendering Library
– Physics Engine
– Input Abstraction
– Fast Math Libraries
– Object Pooling/Resource Management
– Audio Management
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Using a Full Game Engine
• Use some kind of interactive editor
• Provide custom API or scripting language for defining
game mechanics
• More approachable by design and art members of a
development team
• Combines many tools into a single package
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Entity/Component Model
• A pattern that is becoming more popular in game
development
• Used in the Unity Game Engine
• Every game object is an entity which contains different
components
• Those components are acted on by systems that run in
loops
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Example Entity
class Entity {
void AttachComponent(ComponentType, argumentList, name)
void DetachComponent(name) void UpdateComponents()
void UpdateComponentType(ComponentType typeOfComponentToUpdate)
void HandleMessage(MessageType message) // echoes to all attached components
...
BaseComponentList attachedComponentList
.... }
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Example Component
class BaseComponent {
virtual void Startup()
virtual void Update()
virtual void Shutdown()
virtual void HandleMessage(MessageType message) .... }
class RenderComponent: Public BaseComponent {
virtual void Startup() // (registers the renderable mesh with the rendering system)
virtual void Shutdown() // (removes the renderable mesh from the rendering system)
... }
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Components in Unity
• All public members of a script are
exposed in the GUI allowing nonprogrammer team members to control
game settings
• Built in Component types can also be
accessed and edited this way
• Properties can be changed in the GUI
while the game is running to test
changes
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Open Areas for Game Tool
Development
• Implementing AI behaviors (complex simulation in
general)
• Better animation control (some promising recent tools)
• Truly cross-platform deployment (particularly to web)
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Questions?
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