I'm having a constant issue of particle effects not appearing in the editor. Everything works fine when I first create them, but after some time they stop appearing. I just see the black background, but the particles aren't there.
The only way I'm able to deal with this problem is to delete the node and create a new particle node with the same attributes, which is time consuming and annoying. And then, after a while, the same thing happens to the new particle nodes.
Anyone else experience this?
This happens to me all of time after editing a value and switching to code view of another page. Come back and the preview is gone. Can confirm it is still broken in Xcode 7.3 Beta
There are a couple of home remedies that work until it gets fixed by Apple.
Right click on the file --> Open As --> Quick Look select a different file and come back and it should work now
or
Close the emitter document with File --> Close “Particle.sks” (Control-Command-W) and reopening it should circumvent the issue.
Hope this helps in the mean time
来源：https://stackoverflow.com/questions/28141300/spritekit-particle-emitter-not-appearing-in-xcode-editor