three.js/examples/js/cameras/CinematicCamera.js

/**
  * @author mrdoob / http://mrdoob.com/
  * @author greggman / http://games.greggman.com/
  * @author zz85 / http://www.lab4games.net/zz85/blog
  * @author kaypiKun
  */

//Inheriting PerspectiveCamera

THREE.CinematicCamera = function(fov, aspect, near, far){
  THREE.PerspectiveCamera.call(this, fov, aspect, near, far);
  this.type = "CinematicCamera";

  this.postprocessing = { enabled  : true };
  this.shaderSettings = {
    rings: 3,
    samples: 4
  };

  this.material_depth = new THREE.MeshDepthMaterial();
  //In case of cinematicCamera, having a default lens set is important
  this.setLens();

  this.initPostProcessing();
  
};

THREE.CinematicCamera.prototype = Object.create(THREE.PerspectiveCamera.prototype);
THREE.CinematicCamera.prototype.constructor = THREE.CinematicCamera;


//providing fnumber and coc(Circle of Confusion) as extra arguments
THREE.CinematicCamera.prototype.setLens = function ( focalLength, frameHeight, fNumber, coc ) {

  //In case of cinematicCamera, having a default lens set is important
  if ( focalLength === undefined ) focalLength = 35;

  THREE.PerspectiveCamera.prototype.setLens.call( this, focalLength, frameHeight );

  //if fnumber and coc are not provided, cinematicCamera tries to act as a basic PerspectiveCamera
  if ( fNumber === undefined ) fNumber = 8;
  if ( coc === undefined ) coc = 0.019;



  this.focalLength = focalLength;
  this.fNumber = fNumber;
  this.coc = coc;

  //fNumber is focalLength by aperture
  this.aperture = this.focalLength/this.fNumber;

  //hyperFocal is required to calculate depthOfField when a lens tries to focus at a distance with given fNumber and focalLength
  this.hyperFocal = (this.focalLength*this.focalLength)/(this.aperture*this.coc);

};



THREE.CinematicCamera.prototype.linearize = function(depth) {
	var zfar = this.far;
	var znear = this.near;
	return -zfar * znear / (depth * (zfar - znear) - zfar);
}


THREE.CinematicCamera.prototype.smoothstep = function(near, far, depth) {
	var x = this.saturate( (depth - near) / (far - near));
	return x * x * (3- 2*x);
}


THREE.CinematicCamera.prototype.saturate = function(x) {
	return Math.max(0, Math.min(1, x));
}


//function for focusing at a distance from the camera
THREE.CinematicCamera.prototype.focusAt = function (focusDistance){

  if ( focusDistance === undefined ) focusDistance = 20;

  //distance from the camera (normal to frustrum) to focus on (unused)
  this.focusDistance = focusDistance;

  //the nearest point from the camera which is in focus (unused)
  this.nearPoint = (this.hyperFocal*this.focusDistance)/(this.hyperFocal+(this.focusDistance-this.focalLength));

  //the farthest point from the camera which is in focus (unused)
  this.farPoint = (this.hyperFocal*this.focusDistance)/(this.hyperFocal-(this.focusDistance-this.focalLength));

  //the gap or width of the space in which is everything is in focus (unused)
  this.depthOfField = this.farPoint - this.nearPoint;

  //Considering minimum distance of focus for a standard lens (unused)
  if( this.depthOfField < 0) this.depthOfField = 0;
  
  this.sdistance = this.smoothstep(this.near, this.far, this.focusDistance);

	this.ldistance = this.linearize(1 -  this.sdistance);
	
	this.postprocessing.bokeh_uniforms[ 'focalDepth' ].value = this.ldistance;

};



THREE.CinematicCamera.prototype.initPostProcessing = function (){
    if(this.postprocessing.enabled)
    {
        this.postprocessing.scene = new THREE.Scene();

        
        this.postprocessing.camera = new THREE.OrthographicCamera( window.innerWidth / -2, window.innerWidth / 2,  window.innerHeight / 2, window.innerHeight / - 2, -10000, 10000 );
        
    
        this.postprocessing.scene.add( this.postprocessing.camera );

        var pars = { minFilter: THREE.LinearFilter, magFilter: THREE.LinearFilter, format: THREE.RGBFormat };
        this.postprocessing.rtTextureDepth = new THREE.WebGLRenderTarget( window.innerWidth, window.innerHeight, pars );
        this.postprocessing.rtTextureColor = new THREE.WebGLRenderTarget( window.innerWidth, window.innerHeight, pars );


        var bokeh_shader = THREE.BokehShader;

        this.postprocessing.bokeh_uniforms = THREE.UniformsUtils.clone( bokeh_shader.uniforms );

        this.postprocessing.bokeh_uniforms[ "tColor" ].value = this.postprocessing.rtTextureColor;
        this.postprocessing.bokeh_uniforms[ "tDepth" ].value = this.postprocessing.rtTextureDepth;

        this.postprocessing.bokeh_uniforms[ "manualdof" ].value = 0;
				this.postprocessing.bokeh_uniforms[ "shaderFocus" ].value = 0;

        this.postprocessing.bokeh_uniforms[ "fstop" ].value = 2.8;

        this.postprocessing.bokeh_uniforms[ "showFocus" ].value = 1;

        this.postprocessing.bokeh_uniforms[ "focalDepth" ].value = 0.1;

        console.log(this.postprocessing.bokeh_uniforms["focalDepth"].value);

				this.postprocessing.bokeh_uniforms[ "znear" ].value = this.near;
				this.postprocessing.bokeh_uniforms[ "zfar" ].value = this.near;


        this.postprocessing.bokeh_uniforms[ "textureWidth" ].value = window.innerWidth;

        this.postprocessing.bokeh_uniforms[ "textureHeight" ].value = window.innerHeight;

        this.postprocessing.materialBokeh = new THREE.ShaderMaterial({uniforms: this.postprocessing.bokeh_uniforms, vertexShader: bokeh_shader.vertexShader, fragmentShader: bokeh_shader.fragmentShader, defines: { RINGS: this.shaderSettings.rings, SAMPLES: this.shaderSettings.samples } } );

        this.postprocessing.quad = new THREE.Mesh( new THREE.PlaneBufferGeometry( window.innerWidth, window.innerHeight ), this.postprocessing.materialBokeh );
        this.postprocessing.quad.position.z = -500;
        this.postprocessing.scene.add( this.postprocessing.quad );
    }

}

THREE.CinematicCamera.prototype.renderCinematic = function (scene, renderer ){

    if ( this.postprocessing.enabled ) {

      renderer.clear();

      // Render scene into texture

      scene.overrideMaterial = null;
      renderer.render( scene, camera, this.postprocessing.rtTextureColor, true );

      // Render depth into texture

      scene.overrideMaterial = this.material_depth;
      renderer.render( scene, camera, this.postprocessing.rtTextureDepth, true );

      // Render bokeh composite

      renderer.render( this.postprocessing.scene, this.postprocessing.camera );

    }

}