Fix #4983

src/Particles/babylon.baseParticleSystem.ts

@@ -14,11 +14,14 @@ module BABYLON {
          * Blend current color and particle color using particle’s alpha.
          */
         public static BLENDMODE_STANDARD = 1;
-
         /**
          * Add current color and particle color multiplied by particle’s alpha.
          */
         public static BLENDMODE_ADD = 2;
+        /**
+         * Multiply current color with particle color 
+         */
+        public static BLENDMODE_MULTIPLY = 3;        
 
         /**
          * List of animations used by the particle system.

src/Particles/babylon.gpuParticleSystem.ts

@@ -1064,6 +1064,9 @@
                     case ParticleSystem.BLENDMODE_STANDARD:
                         this._engine.setAlphaMode(Engine.ALPHA_COMBINE);
                         break;
+                    case ParticleSystem.BLENDMODE_MULTIPLY:
+                        this._engine.setAlphaMode(Engine.ALPHA_MULTIPLY);
+                        break; 
                 }      
 
                 if (this.forceDepthWrite) {

src/Particles/babylon.particleSystem.ts

@@ -1281,6 +1281,9 @@
                 case ParticleSystem.BLENDMODE_STANDARD:
                     engine.setAlphaMode(Engine.ALPHA_COMBINE);
                     break;
+                case ParticleSystem.BLENDMODE_MULTIPLY:
+                    engine.setAlphaMode(Engine.ALPHA_MULTIPLY);
+                    break;                    
             }
 
             if (this.forceDepthWrite) {