diff --git a/packages/physics/traits/emitter.trait.js b/packages/physics/traits/emitter.trait.js
index 030b783..de1d9dd 100644
--- a/packages/physics/traits/emitter.trait.js
+++ b/packages/physics/traits/emitter.trait.js
@@ -83,6 +83,12 @@ export class Emitter extends decorate(Trait) {
     return hooks;
   }
 
+  emitParticleJson(json) {
+    return Entity.loadOrInstance(json).then((particle) => {
+      this.entity.emitParticleEntity(particle);
+    });
+  }
+
   listeners() {
     return {
 
@@ -151,30 +157,18 @@ export class Emitter extends decorate(Trait) {
       },
 
       emitParticleJson: (json) => {
-        return Entity.loadOrInstance(json).then((particle) => {
-          this.entity.emitParticleEntity(particle);
-          return particle;
-        });
-      },
-
-      emitParticle: (key, order = {}) => {
-        const particleJson = this.particles[key]
-        if (!particleJson) {
-          return;
-        }
-        const mergedJson = merge({}, particleJson, order);
         let {
           count = 1,
           rate = 0,
-        } = mergedJson;
+        } = json;
         if (0 === rate) {
           for (let i = 0; i < count; ++i) {
-            this.entity.emitParticleJson(mergedJson);
+            this.emitParticleJson(json);
           }
         }
         else {
           const ticker = new Ticker(rate);
-          this.entity.emitParticleJson(mergedJson);
+          this.emitParticleJson(json);
           count -= 1;
           if (count > 0) {
             const removeEmission = () => {
@@ -185,7 +179,7 @@ export class Emitter extends decorate(Trait) {
             };
             this.entity.on('destroy', removeEmission);
             ticker.on('tick', () => {
-              this.entity.emitParticleJson(mergedJson);
+              this.emitParticleJson(json);
               if (0 >= --count) {
                 removeEmission();
               }
@@ -195,6 +189,15 @@ export class Emitter extends decorate(Trait) {
         }
       },
 
+      emitParticle: (key, json = {}) => {
+        const particleJson = this.particles[key]
+        if (!particleJson) {
+          return;
+        }
+        const mergedJson = merge({}, particleJson, json);
+        this.entity.emitParticleJson(mergedJson);
+      },
+
     };
   }