Topics

Task guides for one system at a time: rendering, physics, animation, audio, input, UI, cameras, streaming, and the rest of what a world needs.

• Showing an animated image

  An animated GIF, APNG or animated WebP imports as one texture carrying every frame: one layer per frame, plus the display time each frame was authored with.

• Animation

  Animated models in Zero carry named clips (idle, walk, run, …).

• Audio

  Audio in Zero is built from two components. An Audio component makes an entity emit sound from a .soundClip asset.

• The shell

  bash is a complete bash shell running inside the engine, over this world's files and the engine's live state.

• Building a game — the play-mode authoring loop

  A game in Zero is a scene the world loads: its entities, their components, the player avatar, and the camera.

• Byte streams: talking to things outside the engine

  A world often needs to speak to something that is not part of it — a socket on another machine, an external process on localhost…

• Camera input: a webcam or phone camera in the world

  The camera global and the Camera component are the world's own cameras, the ones the scene is rendered through.

• Cameras — which one is rendering, with what projection, into what

  A camera is an entity carrying a Camera component.

• Cutscenes

  A cutscene is the moment your game takes the camera off the player: the opening that establishes where they are, the door that opens once, the ending.

• The editor UI

  Everything you see when you edit a world — the menu bar across the top, the dockable panels, the play controls — is world-side Luau content…

• Engine API in an external editor

  The engine describes its whole Luau API (every global namespace, method signature, published type alias and asset-category surface) as a Luau definitions file…

• Streaming frames out of the engine

  Sometimes the rendered image has to leave the machine.

• Graphics quality on phones and desktops: the device's quality tier

  How the engine fits its rendering to the device a world is played on: a phone, a tablet, a laptop, a desktop or a browser.

• Serving HTTP from the running world

  Sometimes something outside the engine has to reach in.

• Inverse kinematics

  An animation clip stores joint angles. Play it and the character does the same thing every time…

• Input

  A player might be at a keyboard, holding a controller, or tapping a phone.

• The player's language

  Every engine knows which languages its player reads, on every platform, and picks from one chain.

• The microphone: sound coming in

  The audio guide is about sound the world makes. This one is about sound the world hears — audio input from the machine it is running on.

• Physics

  Physics in Zero has two surfaces, reached in two different ways:

• Ray tracing

  Cast rays against the live scene from a compute shader and shade with the hits — shadows, ambient occlusion, reflections, GI.

• Recording: filming the world and keeping the video

  av turns what the engine draws into a video file: a clip a player captures of something fun, a replay, a trailer or cutscene filmed frame by frame…

• Render layers

  A render layer is a name. An entity is a member of one or more layers; a camera draws a filter over them ("all !shell").

• Render textures

  A render texture is a camera's view drawn into a texture instead of onto the screen.

• Rendering

  Most of how a scene looks comes from its content — meshes, materials, and lights.

• Quality tiers, render target cost and loaded content

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Debug camera views

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• What drawing costs: culling, materials and crowds

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Morph targets, clusters and lines

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Per-entity shader data

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Lighting and global illumination

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Material graphs

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Motion blur and the velocity buffer

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Post-process

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Reflections

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Render features

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Asking where the drawn world is along a ray

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Scene-wide renderer settings

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Shadows: budgets, casters and what each light costs

  Part of the rendering guide (guides { path = "topics/rendering" }), which lists every part.

• Styling

  Every visual property of a widget lives in one table — the style table on the widget node — and the vocabulary is CSS.

• Text and labels

  Text in a world comes from one place: a text object the engine holds, laid out against a font database and rasterised into a GPU texture.

• The UI window system

  UI in Zero is declarative and immediate-mode: you describe the interface as a tree of widget tables and register it as a named screen…

• Visual effects

  A visual effect in Zero (sparks, fire, smoke, magic, an impact, a muzzle flash, a swarm, lightning) is an entry of an effect…

• World detail — terrain, voxels, streaming, LOD

  Four systems decide how much of a world stands at any one moment: