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Rendering.md

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+The library comes packaged with two simple render modules for displaying worlds [Matter.Render](http://brm.io/matter-js-docs/classes/Render.html) and [Matter.RenderPixi](http://brm.io/matter-js-docs/classes/RenderPixi.html).
+
+## Matter.Render
+
+The default renderer is [Matter.Render](http://brm.io/matter-js-docs/classes/Render.html) which uses a simple HTML5 canvas in immediate mode. It has built in support for both primitive and sprite based rendering of bodies in 2d.
+
+When you use `Engine.create(element)` a `Matter.Render` instance will be created for you and it will automatically insert a canvas into the page at the specified `element`.
+
+Following this calling `Engine.run(engine)` will spawn the built in game loop routine, which will automatically manage updating the engine and calling the renderer at the appropriate times.
+
+#### Render options
+
+A number of options may be passed to the renderer:
+
+```js
+Engine.create({
+    render: {
+        options: {
+            width: 800,
+            height: 600,
+            background: '#fafafa',
+            wireframeBackground: '#222',
+            hasBounds: false,
+            enabled: true,
+            wireframes: true,
+            showSleeping: true,
+            showDebug: false,
+            showBroadphase: false,
+            showBounds: false,
+            showVelocity: false,
+            showCollisions: false,
+            showAxes: false,
+            showPositions: false,
+            showAngleIndicator: false,
+            showIds: false,
+            showShadows: false
+        }
+    }
+})
+```
+
+## Matter.RenderPixi
+
+An alternate renderer [Matter.RenderPixi](http://brm.io/matter-js-docs/classes/RenderPixi.html) is provided as an example of using [Pixi.js](http://www.pixijs.com/) to render a world using WebGL and a scene graph. The features available should match those of `Matter.Render` although sometimes there may be implementation differences.
+
+To make use of this module you must pass it to your engine at its creation:
+
+```js
+Engine.create({
+    render: {
+        element: document.body,
+        controller: Matter.RenderPixi
+    }
+})
+```
+
+## Using a custom renderer
+
+While the built in renderers are useful for early development, if you need to do any kind of complex rendering effects you will need a custom renderer.
+
+The easiest way to do this is to simply copy [Render.js](https://github.com/liabru/matter-js/blob/master/src/render/Render.js) and customise it, giving it a new module name.
+
+To then use your custom renderer you must pass it to your engine at its creation where `MyRenderer` is the name of your new render module:
+
+```js
+Engine.create({
+    render: {
+        element: document.body,
+        controller: MyRenderer
+    }
+})
+```