ShaderChunk: Moved shadowMask creation to shadowmap_fragment.

src/renderers/shaders/ShaderChunk/shadowmap_fragment.glsl

 #ifdef USE_SHADOWMAP
 
+	vec3 shadowMask = vec3( 1.0 );
+
 	for ( int i = 0; i < NUM_SHADOWS; i ++ ) {
 
 		float texelSizeY =  1.0 / shadowMapSize[ i ].y;

src/renderers/shaders/ShaderLib.js

@@ -89,7 +89,6 @@ THREE.ShaderLib = {
 			"void main() {",
 
 			"	vec4 diffuseColor = vec4( diffuse, opacity );",
-			"	vec3 shadowMask = vec3( 1.0 );",
 
 				THREE.ShaderChunk[ "logdepthbuf_fragment" ],
 				THREE.ShaderChunk[ "map_fragment" ],
@@ -217,7 +216,6 @@ THREE.ShaderLib = {
 			"	vec3 outgoingLight = vec3( 0.0 );",
 			"	vec4 diffuseColor = vec4( diffuse, opacity );",
 			"	vec3 totalAmbientLight = PI * ambientLightColor;",
-			"	vec3 shadowMask = vec3( 1.0 );",
 
 				THREE.ShaderChunk[ "logdepthbuf_fragment" ],
 				THREE.ShaderChunk[ "map_fragment" ],
@@ -372,7 +370,6 @@ THREE.ShaderLib = {
 			"	vec4 diffuseColor = vec4( diffuse, opacity );",
 			"	ReflectedLight reflectedLight = ReflectedLight( vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ) );",
 			"	vec3 totalEmissiveLight = emissive;",
-			"	vec3 shadowMask = vec3( 1.0 );",
 
 				THREE.ShaderChunk[ "logdepthbuf_fragment" ],
 				THREE.ShaderChunk[ "map_fragment" ],
@@ -566,7 +563,6 @@ THREE.ShaderLib = {
 				// modulation
 				THREE.ShaderChunk[ "aomap_fragment" ],
 
-				"vec3 shadowMask = vec3( 1.0 );",
 				THREE.ShaderChunk[ "shadowmap_fragment" ],
 
 				"reflectedLight.directDiffuse *= shadowMask;",
@@ -643,7 +639,6 @@ THREE.ShaderLib = {
 
 			"	vec3 outgoingLight = vec3( 0.0 );",
 			"	vec4 diffuseColor = vec4( psColor, opacity );",
-			"	vec3 shadowMask = vec3( 1.0 );",
 
 				THREE.ShaderChunk[ "logdepthbuf_fragment" ],
 				THREE.ShaderChunk[ "map_particle_fragment" ],