diff --git a/build/three.js b/build/three.js
index 2802a738cfe4cbbffd8593c55a7df78a85dedf22..b72ecf5c3fbb9f06309e5c73dbe37e19e3f6bbbd 100644
--- a/build/three.js
+++ b/build/three.js
@@ -147,6 +147,7 @@ THREE.SrcAlphaSaturateFactor = 210;
 
 THREE.MultiplyOperation = 0;
 THREE.MixOperation = 1;
+THREE.AddOperation = 2;
 
 // Mapping modes
 
@@ -13524,6 +13525,10 @@ THREE.ShaderChunk = {
 
 				"gl_FragColor.xyz = mix( gl_FragColor.xyz, cubeColor.xyz, specularStrength * reflectivity );",
 
+			"} else if ( combine == 2 ) {",
+
+				"gl_FragColor.xyz += cubeColor.xyz * specularStrength * reflectivity;",
+
 			"} else {",
 
 				"gl_FragColor.xyz = mix( gl_FragColor.xyz, gl_FragColor.xyz * cubeColor.xyz, specularStrength * reflectivity );",
diff --git a/build/three.min.js b/build/three.min.js
index c369211d145b7418e006b1374189fefc4608e2f8..2bdf96e8f6c0f7ef9482a48124407f456b1b5617 100644
--- a/build/three.min.js
+++ b/build/three.min.js
@@ -3,7 +3,7 @@
 String.prototype.trim=String.prototype.trim||function(){return this.replace(/^\s+|\s+$/g,"")};
 (function(){for(var a=0,b=["ms","moz","webkit","o"],c=0;c<b.length&&!window.requestAnimationFrame;++c)window.requestAnimationFrame=window[b[c]+"RequestAnimationFrame"],window.cancelAnimationFrame=window[b[c]+"CancelAnimationFrame"]||window[b[c]+"CancelRequestAnimationFrame"];void 0===window.requestAnimationFrame&&(window.requestAnimationFrame=function(b){var c=Date.now(),f=Math.max(0,16-(c-a)),g=window.setTimeout(function(){b(c+f)},f);a=c+f;return g});window.cancelAnimationFrame=window.cancelAnimationFrame||
 function(a){window.clearTimeout(a)}})();THREE.FrontSide=0;THREE.BackSide=1;THREE.DoubleSide=2;THREE.NoShading=0;THREE.FlatShading=1;THREE.SmoothShading=2;THREE.NoColors=0;THREE.FaceColors=1;THREE.VertexColors=2;THREE.NoBlending=0;THREE.NormalBlending=1;THREE.AdditiveBlending=2;THREE.SubtractiveBlending=3;THREE.MultiplyBlending=4;THREE.CustomBlending=5;THREE.AddEquation=100;THREE.SubtractEquation=101;THREE.ReverseSubtractEquation=102;THREE.ZeroFactor=200;THREE.OneFactor=201;THREE.SrcColorFactor=202;
-THREE.OneMinusSrcColorFactor=203;THREE.SrcAlphaFactor=204;THREE.OneMinusSrcAlphaFactor=205;THREE.DstAlphaFactor=206;THREE.OneMinusDstAlphaFactor=207;THREE.DstColorFactor=208;THREE.OneMinusDstColorFactor=209;THREE.SrcAlphaSaturateFactor=210;THREE.MultiplyOperation=0;THREE.MixOperation=1;THREE.UVMapping=function(){};THREE.CubeReflectionMapping=function(){};THREE.CubeRefractionMapping=function(){};THREE.SphericalReflectionMapping=function(){};THREE.SphericalRefractionMapping=function(){};
+THREE.OneMinusSrcColorFactor=203;THREE.SrcAlphaFactor=204;THREE.OneMinusSrcAlphaFactor=205;THREE.DstAlphaFactor=206;THREE.OneMinusDstAlphaFactor=207;THREE.DstColorFactor=208;THREE.OneMinusDstColorFactor=209;THREE.SrcAlphaSaturateFactor=210;THREE.MultiplyOperation=0;THREE.MixOperation=1;THREE.AddOperation=2;THREE.UVMapping=function(){};THREE.CubeReflectionMapping=function(){};THREE.CubeRefractionMapping=function(){};THREE.SphericalReflectionMapping=function(){};THREE.SphericalRefractionMapping=function(){};
 THREE.RepeatWrapping=1E3;THREE.ClampToEdgeWrapping=1001;THREE.MirroredRepeatWrapping=1002;THREE.NearestFilter=1003;THREE.NearestMipMapNearestFilter=1004;THREE.NearestMipMapLinearFilter=1005;THREE.LinearFilter=1006;THREE.LinearMipMapNearestFilter=1007;THREE.LinearMipMapLinearFilter=1008;THREE.UnsignedByteType=1009;THREE.ByteType=1010;THREE.ShortType=1011;THREE.UnsignedShortType=1012;THREE.IntType=1013;THREE.UnsignedIntType=1014;THREE.FloatType=1015;THREE.UnsignedShort4444Type=1016;
 THREE.UnsignedShort5551Type=1017;THREE.UnsignedShort565Type=1018;THREE.AlphaFormat=1019;THREE.RGBFormat=1020;THREE.RGBAFormat=1021;THREE.LuminanceFormat=1022;THREE.LuminanceAlphaFormat=1023;THREE.RGB_S3TC_DXT1_Format=2001;THREE.RGBA_S3TC_DXT1_Format=2002;THREE.RGBA_S3TC_DXT3_Format=2003;THREE.RGBA_S3TC_DXT5_Format=2004;THREE.Clock=function(a){this.autoStart=void 0!==a?a:!0;this.elapsedTime=this.oldTime=this.startTime=0;this.running=!1};
 THREE.Clock.prototype.start=function(){this.oldTime=this.startTime=Date.now();this.running=!0};THREE.Clock.prototype.stop=function(){this.getElapsedTime();this.running=!1};THREE.Clock.prototype.getElapsedTime=function(){return this.elapsedTime+=this.getDelta()};THREE.Clock.prototype.getDelta=function(){var a=0;this.autoStart&&!this.running&&this.start();if(this.running){var b=Date.now(),a=0.001*(b-this.oldTime);this.oldTime=b;this.elapsedTime+=a}return a};
@@ -304,7 +304,7 @@ O.b=Ha.b,l(ma.centroidWorld,ma.normalWorld,O),O.r=O.r*X.r+fa.r,O.g=O.g*X.g+fa.g,
 s(H,G,N,L,Q,ea,P,M),!0===ca.wireframe?r(O,ca.wireframeLinewidth,ca.wireframeLinecap,ca.wireframeLinejoin):t(O)):ca instanceof THREE.MeshNormalMaterial?(O.r=Cb(ma.normalWorld.x),O.g=Cb(ma.normalWorld.y),O.b=Cb(ma.normalWorld.z),s(H,G,N,L,Q,ea,P,M),!0===ca.wireframe?r(O,ca.wireframeLinewidth,ca.wireframeLinecap,ca.wireframeLinejoin):t(O)):ca instanceof THREE.MeshDepthMaterial&&(Ja=k.near,Ta=k.far,$.r=$.g=$.b=1-cc(na.positionScreen.z,Ja,Ta),Y.r=Y.g=Y.b=1-cc(bb.positionScreen.z,Ja,Ta),aa.r=aa.g=aa.b=
 1-cc(yb.positionScreen.z,Ja,Ta),ia.r=ia.g=ia.b=1-cc(F.positionScreen.z,Ja,Ta),ra=oa($,Y,aa,ia),n(H,G,N,L,P,M),z(H,G,N,L,P,M,0,0,1,0,0,1,ra),n(R,ba,Q,ea,ja,S),z(R,ba,Q,ea,ja,S,1,0,1,1,0,1,ra));Na.addRectangle(la)}q.setTransform(1,0,0,1,0,0)}}};
 THREE.ShaderChunk={fog_pars_fragment:"#ifdef USE_FOG\nuniform vec3 fogColor;\n#ifdef FOG_EXP2\nuniform float fogDensity;\n#else\nuniform float fogNear;\nuniform float fogFar;\n#endif\n#endif",fog_fragment:"#ifdef USE_FOG\nfloat depth = gl_FragCoord.z / gl_FragCoord.w;\n#ifdef FOG_EXP2\nconst float LOG2 = 1.442695;\nfloat fogFactor = exp2( - fogDensity * fogDensity * depth * depth * LOG2 );\nfogFactor = 1.0 - clamp( fogFactor, 0.0, 1.0 );\n#else\nfloat fogFactor = smoothstep( fogNear, fogFar, depth );\n#endif\ngl_FragColor = mix( gl_FragColor, vec4( fogColor, gl_FragColor.w ), fogFactor );\n#endif",envmap_pars_fragment:"#ifdef USE_ENVMAP\nuniform float reflectivity;\nuniform samplerCube envMap;\nuniform float flipEnvMap;\nuniform int combine;\n#if defined( USE_BUMPMAP ) || defined( USE_NORMALMAP )\nuniform bool useRefract;\nuniform float refractionRatio;\n#else\nvarying vec3 vReflect;\n#endif\n#endif",
-envmap_fragment:"#ifdef USE_ENVMAP\nvec3 reflectVec;\n#if defined( USE_BUMPMAP ) || defined( USE_NORMALMAP )\nvec3 cameraToVertex = normalize( vWorldPosition - cameraPosition );\nif ( useRefract ) {\nreflectVec = refract( cameraToVertex, normal, refractionRatio );\n} else { \nreflectVec = reflect( cameraToVertex, normal );\n}\n#else\nreflectVec = vReflect;\n#endif\n#ifdef DOUBLE_SIDED\nfloat flipNormal = ( -1.0 + 2.0 * float( gl_FrontFacing ) );\nvec4 cubeColor = textureCube( envMap, flipNormal * vec3( flipEnvMap * reflectVec.x, reflectVec.yz ) );\n#else\nvec4 cubeColor = textureCube( envMap, vec3( flipEnvMap * reflectVec.x, reflectVec.yz ) );\n#endif\n#ifdef GAMMA_INPUT\ncubeColor.xyz *= cubeColor.xyz;\n#endif\nif ( combine == 1 ) {\ngl_FragColor.xyz = mix( gl_FragColor.xyz, cubeColor.xyz, specularStrength * reflectivity );\n} else {\ngl_FragColor.xyz = mix( gl_FragColor.xyz, gl_FragColor.xyz * cubeColor.xyz, specularStrength * reflectivity );\n}\n#endif",
+envmap_fragment:"#ifdef USE_ENVMAP\nvec3 reflectVec;\n#if defined( USE_BUMPMAP ) || defined( USE_NORMALMAP )\nvec3 cameraToVertex = normalize( vWorldPosition - cameraPosition );\nif ( useRefract ) {\nreflectVec = refract( cameraToVertex, normal, refractionRatio );\n} else { \nreflectVec = reflect( cameraToVertex, normal );\n}\n#else\nreflectVec = vReflect;\n#endif\n#ifdef DOUBLE_SIDED\nfloat flipNormal = ( -1.0 + 2.0 * float( gl_FrontFacing ) );\nvec4 cubeColor = textureCube( envMap, flipNormal * vec3( flipEnvMap * reflectVec.x, reflectVec.yz ) );\n#else\nvec4 cubeColor = textureCube( envMap, vec3( flipEnvMap * reflectVec.x, reflectVec.yz ) );\n#endif\n#ifdef GAMMA_INPUT\ncubeColor.xyz *= cubeColor.xyz;\n#endif\nif ( combine == 1 ) {\ngl_FragColor.xyz = mix( gl_FragColor.xyz, cubeColor.xyz, specularStrength * reflectivity );\n} else if ( combine == 2 ) {\ngl_FragColor.xyz += cubeColor.xyz * specularStrength * reflectivity;\n} else {\ngl_FragColor.xyz = mix( gl_FragColor.xyz, gl_FragColor.xyz * cubeColor.xyz, specularStrength * reflectivity );\n}\n#endif",
 envmap_pars_vertex:"#if defined( USE_ENVMAP ) && ! defined( USE_BUMPMAP ) && ! defined( USE_NORMALMAP )\nvarying vec3 vReflect;\nuniform float refractionRatio;\nuniform bool useRefract;\n#endif",worldpos_vertex:"#if defined( USE_ENVMAP ) || defined( PHONG ) || defined( LAMBERT ) || defined ( USE_SHADOWMAP )\n#ifdef USE_SKINNING\nvec4 mPosition = modelMatrix * skinned;\n#endif\n#if defined( USE_MORPHTARGETS ) && ! defined( USE_SKINNING )\nvec4 mPosition = modelMatrix * vec4( morphed, 1.0 );\n#endif\n#if ! defined( USE_MORPHTARGETS ) && ! defined( USE_SKINNING )\nvec4 mPosition = modelMatrix * vec4( position, 1.0 );\n#endif\n#endif",
 envmap_vertex:"#if defined( USE_ENVMAP ) && ! defined( USE_BUMPMAP ) && ! defined( USE_NORMALMAP )\nvec3 nWorld = mat3( modelMatrix[ 0 ].xyz, modelMatrix[ 1 ].xyz, modelMatrix[ 2 ].xyz ) * objectNormal;\nif ( useRefract ) {\nvReflect = refract( normalize( mPosition.xyz - cameraPosition ), normalize( nWorld.xyz ), refractionRatio );\n} else {\nvReflect = reflect( normalize( mPosition.xyz - cameraPosition ), normalize( nWorld.xyz ) );\n}\n#endif",map_particle_pars_fragment:"#ifdef USE_MAP\nuniform sampler2D map;\n#endif",
 map_particle_fragment:"#ifdef USE_MAP\ngl_FragColor = gl_FragColor * texture2D( map, vec2( gl_PointCoord.x, 1.0 - gl_PointCoord.y ) );\n#endif",map_pars_vertex:"#if defined( USE_MAP ) || defined( USE_BUMPMAP ) || defined( USE_NORMALMAP ) || defined( USE_SPECULARMAP )\nvarying vec2 vUv;\nuniform vec4 offsetRepeat;\n#endif",map_pars_fragment:"#if defined( USE_MAP ) || defined( USE_BUMPMAP ) || defined( USE_NORMALMAP ) || defined( USE_SPECULARMAP )\nvarying vec2 vUv;\n#endif\n#ifdef USE_MAP\nuniform sampler2D map;\n#endif",
diff --git a/src/Three.js b/src/Three.js
index 76b8747b3badc44ea18774b5ffc318f2fb39fbe5..41dc0710d3132b21b7ddac5ec6922f4f9fd3a05f 100644
--- a/src/Three.js
+++ b/src/Three.js
@@ -147,6 +147,7 @@ THREE.SrcAlphaSaturateFactor = 210;
 
 THREE.MultiplyOperation = 0;
 THREE.MixOperation = 1;
+THREE.AddOperation = 2;
 
 // Mapping modes
 
diff --git a/src/renderers/WebGLShaders.js b/src/renderers/WebGLShaders.js
index e3bf1ee736971dd0870e31f70a1402f52d476396..7b39177ede94cf1427228dc8b4b025eabe57afc7 100644
--- a/src/renderers/WebGLShaders.js
+++ b/src/renderers/WebGLShaders.js
@@ -126,6 +126,10 @@ THREE.ShaderChunk = {
 
 				"gl_FragColor.xyz = mix( gl_FragColor.xyz, cubeColor.xyz, specularStrength * reflectivity );",
 
+			"} else if ( combine == 2 ) {",
+
+				"gl_FragColor.xyz += cubeColor.xyz * specularStrength * reflectivity;",
+
 			"} else {",
 
 				"gl_FragColor.xyz = mix( gl_FragColor.xyz, gl_FragColor.xyz * cubeColor.xyz, specularStrength * reflectivity );",