three.js/examples/js/postprocessing/SSAOPass.js

'use strict';

/*
 * Screen-space ambient occlusion pass.
 *
 * Has the following parameters
 *  - radius
 *  - onlyAO
 *  - aoClamp
 *  - lumInfluence
 * 
 * To output to screen set renderToScreens true
 *
 * @author alteredq / http://alteredqualia.com/
 * @author tentone
 */
THREE.SSAOPass = function ( scene, camera, width, height ) {

	if ( THREE.SSAOShader === undefined)
	{
		console.warn('THREE.SSAOPass depends on THREE.SSAOShader');
		return new THREE.ShaderPass();
	}

	THREE.ShaderPass.call( this, THREE.SSAOShader );

	this.width = ( width !== undefined ) ? width : 512;
	this.height = ( height !== undefined ) ? height : 512;

	this.renderToScreen = false;

	this.camera2 = camera;
	this.scene2 = scene;

	//Depth material
	this.depthMaterial = new THREE.MeshDepthMaterial();
	this.depthMaterial.depthPacking = THREE.RGBADepthPacking;
	this.depthMaterial.blending = THREE.NoBlending;

	//Depth render target
	this.depthRenderTarget = new THREE.WebGLRenderTarget( this.width, this.height, { minFilter: THREE.LinearFilter, magFilter: THREE.LinearFilter } );
	this.depthRenderTarget.texture.name = 'SSAOShader.rt';
	
	//Shader uniforms
	this.uniforms[ 'tDepth' ].value = this.depthRenderTarget.texture;
	this.uniforms[ 'size' ].value.set( this.width, this.height );
	this.uniforms[ 'cameraNear' ].value = this.camera2.near;
	this.uniforms[ 'cameraFar' ].value = this.camera2.far;

	this.uniforms[ 'radius' ].value = 4;
	this.uniforms[ 'onlyAO' ].value = false;
	this.uniforms[ 'aoClamp' ].value = 0.25;
	this.uniforms[ 'lumInfluence' ].value = 0.7;

	//Setters and getters for uniforms
	var self = this;
	Object.defineProperties(this, {

		radius: {
			get: function() { return this.uniforms[ 'radius' ].value; },
			set: function(value) { this.uniforms[ 'radius' ].value = value; }
		},

		onlyAO: {
			get: function() { return this.uniforms[ 'onlyAO' ].value; },
			set: function(value) { this.uniforms[ 'onlyAO' ].value = value; }
		},

		aoClamp: {
			get: function() { return this.uniforms[ 'aoClamp' ].value; },
			set: function(value) { this.uniforms[ 'aoClamp' ].value = value; }
		},

		lumInfluence: {
			get: function() { return this.uniforms[ 'lumInfluence' ].value; },
			set: function(value) { this.uniforms[ 'lumInfluence' ].value = value; }
		},

	});
}

THREE.SSAOPass.prototype = Object.create( THREE.ShaderPass.prototype );

THREE.SSAOPass.prototype.render = function( renderer, writeBuffer, readBuffer, delta, maskActive ) {

	//Render depth into depthRenderTarget
	this.scene2.overrideMaterial = this.depthMaterial;
	renderer.render( this.scene2, this.camera2, this.depthRenderTarget, true );
	
	//Render renderPass and SSAO shaderPass
	this.scene2.overrideMaterial = null;
	THREE.ShaderPass.prototype.render.call( this, renderer, writeBuffer, readBuffer, delta, maskActive );

};

THREE.SSAOPass.prototype.setSize = function( width, height ) {

	this.width = width;
	this.height = height;

	this.uniforms[ 'size' ].value.set( this.width, this.height );
	this.depthRenderTarget.setSize( this.width, this.height );

};