Modified Anaglyph Renderer to use an asymmetric perspective projection. Added focal length to the equation and updated to allow for camera rotation

src/extras/renderers/AnaglyphWebGLRenderer.js

@@ -2,12 +2,19 @@
  * @author mrdoob / http://mrdoob.com/
  */
 
-THREE.AnaglyphWebGLRenderer = function ( parameters ) {
+THREE.AnaglyphWebGLRenderer = function ( parameters ) {	
 
 	THREE.WebGLRenderer.call( this, parameters );
 
 	var _this = this, _setSize = this.setSize, _render = this.render;
 	var _cameraL = new THREE.Camera(), _cameraR = new THREE.Camera();
+	var eyeRight = new THREE.Matrix4(),
+		eyeLeft = new THREE.Matrix4(),
+		focalLength = 125,
+		aspect, near, fov;
+	
+	_cameraL.useTarget = _cameraR.useTarget = false;
+	_cameraL.matrixAutoUpdate = _cameraR.matrixAutoUpdate = false;
 
 	var _params = { minFilter: THREE.LinearFilter, magFilter: THREE.NearestFilter, format: THREE.RGBAFormat };
 	var _renderTargetL = new THREE.WebGLRenderTarget( 512, 512, _params ), _renderTargetR = new THREE.WebGLRenderTarget( 512, 512, _params );
@@ -74,21 +81,67 @@ THREE.AnaglyphWebGLRenderer = function ( parameters ) {
 
 	};
 
-	this.render = function ( scene, camera, renderTarget, forceClear ) {
-
-		_cameraL.projectionMatrix = camera.projectionMatrix;
+	/*
+	 * Renderer now uses an asymmetric perspective projection (http://paulbourke.net/miscellaneous/stereographics/stereorender/). 
+	 * Each camera is offset by the eye seperation and its projection matrix is also skewed asymetrically back to converge on the same
+	 * projection plane. Added a focal length parameter to, this is where the parallax is equal to 0. 
+	 */
+	this.render = function ( scene, camera, renderTarget, forceClear ) {	
+		
+		
+		camera.update( null, true );
+		
+		var hasCameraChanged = 	aspect !== camera.aspect || 
+								near !== camera.near ||
+								fov !== camera.fov;
+								
+		if( hasCameraChanged )
+		{
+		
+			aspect = camera.aspect;
+			near = camera.near;
+			fov = camera.fov;	
+		
+			var projectionMatrix = camera.projectionMatrix.clone(),
+				eyeSep = focalLength / 30 * 0.5,
+				eyeSepOnProjection = eyeSep * near / focalLength,
+				ymax = near * Math.tan( fov * Math.PI / 360 ),
+				xmin, xmax;
+
+			//translate xOffset
+			eyeRight.n14 = eyeSep;
+			eyeLeft.n14 = -eyeSep;
+	
+			//For left eye
+			xmin = -ymax * aspect + eyeSepOnProjection;
+			xmax = ymax * aspect + eyeSepOnProjection;
+			projectionMatrix.n11 = 2 * near / ( xmax - xmin );
+			projectionMatrix.n13 = ( xmax + xmin ) / ( xmax - xmin );
+			_cameraL.projectionMatrix = projectionMatrix.clone();
+			
+			//for right eye		
+			xmin = -ymax * aspect - eyeSepOnProjection;
+			xmax = ymax * aspect - eyeSepOnProjection;
+			projectionMatrix.n11 = 2 * near / ( xmax - xmin );
+			projectionMatrix.n13 = ( xmax + xmin ) / ( xmax - xmin );
+			_cameraR.projectionMatrix = projectionMatrix.clone();
+				
+		}	
+		
+		_cameraL.matrix = camera.matrixWorld.clone().multiplySelf( eyeLeft );
+		_cameraL.update(null, true);
 		_cameraL.position.copy( camera.position );
-		_cameraL.target.position.copy( camera.target.position );
-		_cameraL.translateX( - 10 );
+		_cameraL.near = near;
+		_cameraL.far = camera.far;
+		_render.call( _this, scene, _cameraL, _renderTargetL, true );
 
-		_cameraR.projectionMatrix = camera.projectionMatrix;
+		_cameraR.matrix = camera.matrixWorld.clone().multiplySelf( eyeRight );
+		_cameraR.update(null, true);
 		_cameraR.position.copy( camera.position );
-		_cameraR.target.position.copy( camera.target.position );
-		_cameraR.translateX( 10 );
-
-		_render.call( _this, scene, _cameraL, _renderTargetL, true );
+		_cameraR.near = near;
+		_cameraR.far = camera.far;
 		_render.call( _this, scene, _cameraR, _renderTargetR, true );
-
+		
 		_render.call( _this, _scene, _camera );
 
 	};