Merge pull request #10446 from dpotekhin/patch-1

Update StereoCamera.js

src/cameras/StereoCamera.js

@@ -28,7 +28,7 @@ Object.assign( StereoCamera.prototype, {
 
 	update: ( function () {
 
-		var instance, focus, fov, aspect, near, far, zoom;
+		var instance, focus, fov, aspect, near, far, zoom, eyeSep;
 
 		var eyeRight = new Matrix4();
 		var eyeLeft = new Matrix4();
@@ -37,7 +37,7 @@ Object.assign( StereoCamera.prototype, {
 
 			var needsUpdate = instance !== this || focus !== camera.focus || fov !== camera.fov ||
 												aspect !== camera.aspect * this.aspect || near !== camera.near ||
-												far !== camera.far || zoom !== camera.zoom;
+												far !== camera.far || zoom !== camera.zoom || eyeSep !== this.eyeSep;
 
 			if ( needsUpdate ) {
 
@@ -53,7 +53,7 @@ Object.assign( StereoCamera.prototype, {
 				// http://paulbourke.net/stereographics/stereorender/
 
 				var projectionMatrix = camera.projectionMatrix.clone();
-				var eyeSep = this.eyeSep / 2;
+				eyeSep = this.eyeSep / 2;
 				var eyeSepOnProjection = eyeSep * near / focus;
 				var ymax = ( near * Math.tan( _Math.DEG2RAD * fov * 0.5 ) ) / zoom;
 				var xmin, xmax;