SPS disappears when looking down or “behind” Seems to be culling the mesh when viewed from certain angles. View point IS inside the particle system, so maybe that’s part of the reason.
Simply add an XR experience to the demo SPS to see the issue.
Thanks
Interesting 
The minute the base mesh is out of the camera’s frustum, it disappears (because it is not set as an active mesh anymore). The demo is using an arc rotate camera that is always looking at the active mesh. If you move to a free camera (for example) and pan (like you would in WebXR) the same effect happens:
SPS Examples | Babylon.js Playground (babylonjs.com)
A quick solution would be to set the mesh as always active - SPS Examples | Babylon.js Playground (babylonjs.com)
Maybe we should consider setting the mesh’s bounding info to be the entire content of the SPS and not just the single mesh to avoid this issue. I’ll create a github issue and we’ll see if and when we’ll tackle it. But for now - always set as active mesh is your friend
Thanks!, I had animated the mesh hoping to get that result… didn’t know I could just set it like that… !