Home What It's All About Who Is This Guy? The List Complete Archive Personal  RSS Feed People		The List By Kyle Wilson Thursday, June 06, 2002 I said in What It's All About that game engine designs are pulled in all directions by a variety of requirements.  It's easy to get too lost in the details of a small subset of the game engine and write code that breaks other functionality or, more subtly, makes other features impossible to add later. So this page is... in flux, and will probably always be in flux.  It's a place for me to jot down, with minimal organization, brainstorm-style, different features that make a good engine and different mechanisms that support solid code.  When this list achieves some kind of critical mass, I hope to go back and annotate it with the connections between items.  The connections aren't always obvious. Every decision you make requires commitment.  Every decision you make narrows your future possibilities.  Design for flexibility when you can, but when you can't, remember that it's always better to make a decision than not to make one at all. The List name-based object registry graphics scene hierarchy skinning shadow / lighting model HDR decals particle systems shader model / material system / associated tools vertex animation alpha sorting terrain culling/occlusion frame buffer post-processing effects split-screen support view modes (AVP2 thermal vision, etc.) mirrors/reflection procedural geometry text rendering/font issues level of detail resource management asynchronous loading resource lifetimes streaming resource scheduling recording/playback frame-based time-based file access pack files fastload linear file image support input remapping force feedback (okay, it's not input...) game timer - frame timer, high resolution profile timer, multiple timer support saving dynamic state exporting constant state cross-platform compatibility - don't forget I/O byte-order issues message passing internal game object structure - how to separate components? external game object structure - hierarchy, dependency graph? in-game UI in-game cinematics tools classes to support easy tool UI creation level editor terrain editor particle system editor model/animation viewers trigger system tool cinematics tool MAX plug-ins - exporter(s?), material profiling console data pipeline conversion - optimization for multiple platforms sound - 3D, 2D, looping, looping subrange, effects music scripting - Python?  Lua?  Java?  Roll your own? script debugging exposing code objects to script deciding who writes the scripts network security/hacking issues latency bandwidth usage error handling physics - how to structure main loop?  frame time or independent?  interpolation between physics ticks? stable integration collision detection - what shapes?  continuous or discrete? collision response - approximation?  impulse-based?  penalty methods? inverse kinematics line of sight/ray queries AI fuzzy logic state machines path-finding tools animation and controllers/dynamics - for transforms, colors, floats lip-sync/sound synchronization interaction of animation and physics memory management RTTI - use C++?  Roll your own?  Do unsafe casts? exception safety ala Herb Sutter levelization ala John Lakos localization enhancing concurrency/multi-threading If you can think of anything I've missed -- and you probably can, since this isn't a well-bounded question -- drop me an e-mail.. I'm Kyle Wilson.  I've worked in the game industry since I got out of grad school in 1997.  Any opinions expressed herein are in no way representative of those of my employers.
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