Reverted shadowDarkness removal. See #7321.

src/lights/Light.js

@@ -71,7 +71,7 @@ Object.defineProperties( THREE.Light.prototype, {
 	},
 	shadowDarkness: {
 		set: function ( value ) {
-			console.warn( 'THREE.Light: .shadowDarkness has been removed.' );
+			this.shadow.darkness = value;
 		}
 	},
 	shadowMapWidth: {

src/lights/LightShadow.js

@@ -7,6 +7,7 @@ THREE.LightShadow = function ( camera ) {
 	this.camera = camera;
 
 	this.bias = 0;
+	this.darkness = 1;
 
 	this.mapSize = new THREE.Vector2( 512, 512 );
 

src/renderers/WebGLRenderer.js

@@ -2002,11 +2002,11 @@ THREE.WebGLRenderer = function ( parameters ) {
 						shadow.matrix.identity().setPosition( _vector3 );
 
 						// for point lights we set the sign of the shadowDarkness uniform to be negative
-						uniforms.shadowDarkness.value[ j ] = - 1.0;
+						uniforms.shadowDarkness.value[ j ] = - shadow.darkness;
 
 					} else {
 
-						uniforms.shadowDarkness.value[ j ] = 1.0;
+						uniforms.shadowDarkness.value[ j ] = shadow.darkness;
 
 					}