Overview

This section describes the engine’s internals: the model each subsystem imposes on a game, how that subsystem behaves, and why it is shaped that way. It states the model and the guarantees; the exact surface is at APIs and the idioms are at Usage.

Four properties run through every page. A game reaches the engine through the framework object it is inside rather than through a global. Input reaches the simulation only through a controller. Drawing happens only in the rendering pipeline. Everything the engine observes it broadcasts as an event a caller subscribes to.

Pages

Page	Covers
Frame	The loop, the fixed frame order, the pipeline’s place in it, simulated time, the clock behind delta time, and pausing.
World	What a level describes, what opening one builds, the transition sequence, and what crosses it.
Gameplay Framework	The game instance, the game mode, the game state, and the player states, and what each one is scoped to.
Actors and Components	Actors as the things in a world, the transform with its quaternion rotation, components as the behavior and appearance attached to an actor, the offset composition, and the deferred destroy.
Possession	Controllers as the one path from input to the simulation, possessing a pawn, and driving the same pawn from a player or a bot.
Rendering	The declarative pipeline, the world pass through the camera and the screen pass over it, the layer ordering, the render modes, and the direct-drawing paths.
Camera and Viewport	The three spaces, the camera’s projection, following a view target and bounds, picking along a ray, and the letterboxed fit.
Collision	Channels and responses, the volumetric shapes, the pairs the engine reports, the manifold, and the queries.
Input	Named actions over bindings, magnitudes and edges consumed per controller, the pointer, and the touch layout catalogue with its sticks.
Audio	Synthesized and file-backed cues, positional playback heard from the camera, the first-interaction unlock, and the cue events.
Assets	The single asset root, path resolution, the texture and model loaders, and the load events.
Diagnostics	The instance and world registries, the overlay drawn on the screen layer in device space, and the frame metrics with the renderer’s counts.
Debug Surface	The object initialize returns, whose poses and readings act on the live world and are driven from code.
Recording	A recording as a video of the frames the engine drew, what a frame is and when it is taken, simulated-time timestamps and keyframes, the bracket and the frame bound, the recorder armed around a section, and two recordings scrubbed in step.