Tutorial by Examples: g

Common Lisp has 12 type specific operators to compare two characters, 6 of them case sensitives and the others case insensitives. Their names have a simple pattern to make easy to remember their meaning: Case SensitiveCase InsensitiveCHAR=CHAR-EQUALCHAR/=CHAR-NOT-EQUALCHAR<CHAR-LESSPCHAR<=CHA...

The core idea is to use GameObjects to represent singletons, which has multiple advantages: Keeps complexity to a minimum but supports concepts like dependency injection Singletons have a normal Unity lifecycle as part of the Entity-Component system Singletons can be lazy loaded and cached loca...

We can use the componentchanged event to listen for changes to the entity: entity.addEventListener('componentchanged', function (evt) { if (evt.detail.name === 'position') { console.log('Entity has moved from', evt.detail.oldData, 'to', evt.detail.newData, '!'); } });

We can use the child-attached and child-detached events to listen for when the scene attaches or detaches an entity: entity.addEventListener('child-attached', function (evt) { if (evt.detail.el.tagName.toLowerCase() === 'a-box') { console.log('a box element has been attached'); }; }); ...

We can simply retrieve an entity using DOM APIs. <a-entity id="mario"></a-entity> var el = document.querySelector('#mario');

For example, if we wanted to grab an entity’s three.js camera object or material object, we could reach into its components var camera = document.querySelector('a-entity[camera]').components.camera.camera; var material = document.querySelector('a-entity[material]').components.material.material; ...

A system is registered similarly to a A-Frame component. If the system name matches a component name, then the component will have a reference to the system as this.system: AFRAME.registerSystem('my-component', { schema: {}, // System schema. Parses into `this.data`. init: function () { ...

An instantiated system can be accessed through the scene: document.querySelector('a-scene').systems[systemName]; Registered system prototypes can be accessed through AFRAME.systems.

Systems can help separate logic and behavior from data if desired. We let systems handle the heavy lifting, and components only worry about managing its data through its lifecycle methods: AFRAME.registerSystem('my-component', { createComplexObject: function (data) { // Do calculations ...

There is no strict API for defining how systems manage components. A common pattern is to have components subscribe themselves to the system. The system then has references to all of its components: AFRAME.registerSystem('my-component', { init: function () { this.entities = []; }, ...

AFRAME.registerComponent (name, definition) Register an A-Frame component. We must register components before we use them anywhere in . Meaning from an HTML file, components should come in order before . {string} name - Component name. The component’s public API as represented through an HTML at...

The schema is an object that defines and describes the property or properties of the component. The schema’s keys are the names of the property, and the schema’s values define the types and values of the property (in case of a multi-property component): Defining schema in your component AFRAME.reg...

A component’s members and methods can be accessed through the entity from the .components object. Look up the component from the entity’s map of components, and we’ll have access to the component’s internals. Consider this example component: AFRAME.registerComponent('foo', { init: function () { ...

Components can be attached to the scene as well as entities. A-Frame ships with a few components to configure the scene: ComponentDetailsembeddedRemove fullscreen styles from the canvas.fogAdd fog.keyboard-shortcutsToggle keyboard shortcuts.inspectorInject the A-Frame Inspector.statsToggle performa...

We place assets within <a-assets>, and we place <a-assets> within <a-scene>. Assets include: <a-asset-item> - Miscellaneous assets such as 3D models and materials <audio> - Sound files <img> - Image textures <video> - Video textures The scene won't...

Since A-Frame fetches assets using XHRs, browser security requires the browser to serve assets with cross-origin resource sharing (CORS) headers if the asset is on a different domain. Otherwise, we'd have to host assets on the same origin as the scene. For some options, GitHub Pages serves every...

Audio and video assets will only block the scene if we set autoplay or if we set preload="auto": <a-scene> <a-assets> <!-- These will not block. --> <audio src="blockus.mp3"></audio> <video src="loadofblocks.mp4">&...

We can set a timeout that when reached, the scene will begin rendering and entities will begin initializing regardless of whether all the assets have loaded. The default timeout is 3 seconds. To set a different timeout, we just pass in the number of milliseconds to the timeout attribute: If some...

Content fetched by <a-asset-item> will be returned as plain text. If we want to use a different response type such as arraybuffer, use <a-asset-item>'s response-type attribute: <a-asset-item response-type="arraybuffer" src="model.gltf"></a-asset-item> ...

A-Frame's animation system can animate different types of properties. vec3 Properties A-Frame has standard vec3 components (i.e., position, rotation, and scale). These components consist of three factors: X, Y, and Z. We can pass three space-delimited numbers to the from and to attributes just a...