Add option for debug shapes drawing for particle emitters

#3267

Source/Editor/Viewport/Previews/ParticleSystemPreview.cs

@@ -246,6 +246,14 @@ namespace FlaxEditor.Viewport.Previews
             }
         }
 
+        /// <inheritdoc />
+        protected override void OnDebugDraw(GPUContext context, ref RenderContext renderContext)
+        {
+            base.OnDebugDraw(context, ref renderContext);
+
+            _previewEffect.OnDebugDraw();
+        }
+
         /// <inheritdoc />
         public override void Draw()
         {
@@ -295,7 +303,8 @@ namespace FlaxEditor.Viewport.Previews
         /// <inheritdoc />
         public override void OnDestroy()
         {
-            // Cleanup objects
+            if (IsDisposing)
+                return;
             _previewEffect.ParticleSystem = null;
             Object.Destroy(ref _previewEffect);
             Object.Destroy(ref _boundsModel);

Source/Editor/Windows/Assets/ParticleEmitterWindow.cs

@@ -127,6 +127,8 @@ namespace FlaxEditor.Windows.Assets
                 PlaySimulation = true,
                 Parent = _split2.Panel1
             };
+            _preview.PreviewActor.ShowDebugDraw = true;
+            _preview.ShowDebugDraw = true;
 
             // Asset properties proxy
             _properties = new PropertiesProxy();