Weird square on scene with SSAO shader - three.js

Question

I'm running following code (jsfiddle: http://jsfiddle.net/sx9p7/ ) :
var scene, camera, renderer, composer;
var l1, l2, hemiLight;
var effectSSAO;
init();
animate();
function init() {
renderer = new THREE.WebGLRenderer( { antialias: false, alpha: false } );
renderer.shadowMapEnabled = true;
renderer.setClearColor( 0xd8e7ff );
renderer.setSize( 800,600);
document.body.appendChild( renderer.domElement );
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera( 40, 800 / 600, 1, 10000 );
camera.position.set(-200,100,-60);
camera.lookAt(new THREE.Vector3(0,0,0));
var container = document.createElement( 'div' );
document.body.appendChild( container );
composer = new THREE.EffectComposer( renderer );
composer.addPass( new THREE.RenderPass( scene, camera ) );
effectSSAO = new THREE.ShaderPass( THREE.SSAOShader );
effectSSAO.renderToScreen = true;
composer.addPass( effectSSAO );
hemiLight = new THREE.HemisphereLight( 0xffffff, 0xffffff, 0.4 );
hemiLight.position.set( 0, 300, 0 );
scene.add( hemiLight );
l1 = new THREE.DirectionalLight( 0xffffff, 0.3);
l1.position.set( 100, 100, 0 );
l1.castShadow = true;
scene.add(l1);
l2 = new THREE.DirectionalLight( 0xffffff, 0.3);
l2.position.set( -100, 100, 0 );
l2.castShadow = true;
scene.add(l2);
var plane = new THREE.Mesh( new THREE.PlaneGeometry( 200, 200), new THREE.MeshLambertMaterial({ }) );
plane.receiveShadow = true;
plane.castShadow = true;
plane.rotation.x = - 90 * Math.PI / 180;
plane.position.set(0,0,0);
scene.add( plane );
var cube = new THREE.Mesh(new THREE.CubeGeometry(50, 50, 50), new THREE.MeshPhongMaterial( { color: 0xaaaaaa, ambient: 0xbbbbbb, specular: 0xcccccc, perPixel: true, vertexColors: THREE.FaceColors } ));
cube.receiveShadow = true;
cube.castShadow = true;
scene.add(cube);
}
function animate() {
requestAnimationFrame( animate );
composer.render();
}
and i have a problem with SSAO shader. I did try many parameters, codes, examples but still i can't remove that square which is in the middle of scene ( which sometime look like correct SSAO effect but in wrong position ??? )
If i will remove one directional light fragment is gone - but still no SSAO effect and shadows are still super very low resolution.

Answer 1

Well, 2 directional lights are strange anyway, just leave it at 1 for the moment.
Concerning the SSAO, see the shader and its numerous parameters. you would need to adjust those according to your scene. example:
effectSSAO .uniforms[ 'tDepth' ].value = depthTarget;
effectSSAO .uniforms[ 'size' ].value.set( width, height );
effectSSAO .uniforms[ 'cameraNear' ].value = 0.1;
effectSSAO .uniforms[ 'cameraFar' ].value = 1000;
As you see above, you also need more than just a few parameter tweaks.
The Three.SSAO shader expects a previously rendered depth pass to work properly.
See here for more help:
How to use the three.js SSAO shader?