Is it possible to use a simulation space besides local or global?

Is there any way to use an arbitrary transform as the simulation space for a particle system? I’ve got a bunch of GameObjects with a highly-mobile camera in their ancestry, and I’d like for the simulation to all take place relative to the camera. Any ideas?

Use a 2nd immobile “GUI particle” camera, clearFlag=none? Aimed at y= -1000 or somewhere (or set all the layers and ignoreLayers correctly.)

Anything spawning on a GUI element would use screenToWorld on the guiCam (same as normal.) Anything spawning over a world object could use worldToView on MainCam, then ViewToWorld on giuCam. Uggg, but only on spawning.

Anything tracking a world object would have to go into a list and each frame do that math (but I wouldn’t think those would be “gui-particles” anyway.)