粒子功能实现和问题解决

src/components/sceneAtttribute/ParticleSystem/ParticleSystem.vue

@@ -631,6 +631,9 @@ export default {
       });
       pointParticleSystemDrawHandler.movingEvt.addEventListener(
         (windowPosition) => {
+          if (!window.tooltip) {
+            window.tooltip = createTooltip(viewer._element);
+          }
           window.tooltip.showAt(
             windowPosition,
             "<p>点击确定粒子位置</p><p>点击选中粒子可进行更改属性</p>"