render-machine-3js

RenderMachine Three.js

RenderMachine Three.js is an npm module that provides a convenient wrapper for handling rendering with Three.js.

RenderMachine is built as a common JS module, and is intended to be used with [Browserify].

#Installation

Install from npm:

$ npm install render-machine-3js

Install from Github:

$ npm install git+https://github.com/ErikPeterson/render-machine-3js.git

#Tests

To run tests, clone the repo and run npm install && npm test

#Usage

If you've never used Three.js before, you should probably run through one of the many introductory tutorials for the library before using RenderMachine.

Three.js includes a suite of Renderer classes that handle the heavy lifting of turning your Three.js scenes into pixels in the browser.

What the Three.js classes don't handle is hooking in to the requestAnimationFrame cycle of the browser and rendering frames.

If you've run through the basic Three.js tutorial before, you'll recognize this snippet of code:

function render() {
	requestAnimationFrame(render);
	renderer.render(scene, camera);
}
render();

This is the most basic way of attaching to requestAnimationFrame and rendering a scene. However, this format gives you no way to control basic features of rendering like frame rate, and brittly depends on the presence of renderer, camera, and scene variables being in scope.

RenderMachine allows you to create an function that has swappable camera, renderer, and scene properties, and event hooks for different parts of the rendering cycle.

To use RenderMachine, you'll need to require Three.js as a commonjs module. The minified script provided on the Three.js site is UMD wrapped, so you can manually include the depency, or use the npm wrapper, three.

var THREE = require('three');
var RenderMachine = require('render-machine-3js');

var rm = new RenderMachine();

Or, to provision your RenderMachine at instantiation, and start the render cycle:

var camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 1, 10000 );
var scene = new THREE.Scene();
var geometry = new THREE.BoxGeometry( 200, 200, 200 );
var material = new THREE.MeshBasicMaterial( { color: 0xff0000, wireframe: true } );

var mesh = new THREE.Mesh( geometry, material );
scene.add( mesh );

var renderer = new THREE.CanvasRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );

document.body.appendChild( renderer.domElement );

var rm = new RenderMachine({camera: camera, renderer: renderer, scene: scene});

rm.render();

Hook in to events:

function firstRenderCallback(){
	console.log("Just executed first render!");
}

rm.on('firstRender', firstRenderCallback);

rm.render();

//=> "Just executed first render!";

Swap out a camera:

var newCam = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 1, 10000 );

rm.camera = newCam;

##Methods

new RenderMachine([options])

A RenderMachine can be instantiated with or without a hash of options. The camera, scene, renderer, and fps properties can be set at instantiation.

• camera an instance of one of the Three.js Camera objects
• scene an instance of THREE.Scene
• renderer an instance of one of the Three.js Renderer objects
• fps sets the framerate for the render cycle. Defaults to 60. Values higher than 60 are probably not a good idea.

#render()

Begins the render cycle. This method calls the render method of the THREE.Render object registered to the RenderMachine, and recursively calls itself on a timer controlled by the RenderMachine's fps property.

#on('eventname', fn, [this])

Register a callback function to one of the events emitted by the RenderMachine.

Available events:

• firstRender callbacks fire once immediately after the first time #render is called.
• beforeRender callbacks fire each time the render cycle begins, before the timeout for the next frame is set.
• render callbacks fire immediately after the timeout for the next frame is set and before the THREE renderer's render method is called.
• afterRender callbacks fire immediate after the THREE renderer's render method is called

#off('eventname', fn)

Unset a callback. To unset, you must pass the name of the event the callback was registered to, and the original callback function object.

#trigger('eventname', [arguments])

Trigger an event by name, with optional arguments to be passed to the callbacks.

#To Do

• add require.js support maybe
• add get and set methods for properties
• add support for collections of switchable cameras, scenes, and renderers