Particle systems' physics heavily depends on framerate?

Question

We are making a 2d game and I stumbled upon some strange behavior.

When I made some particle systems in Unity3d itself, everything was looking right. When I made an application and started it on maximum settings, particles were behaving themselves like crazy. When I started at low settings and they were good.

I found out that it depends on vsync setting (and FPS, as result). Now, without vsync FPS is 1100 (with vsync: 60). Maybe even the whole physics is changing, I haven't spotted that yet.

So the question is: how can I fix this? I can't just turn off the very possibility to turn vsync on, because as I understand, when a game will become more complicated, FPS will drop, and then what? Redo all particle systems? And tearing may appear, why do so?

On the other hand I can't force VSYNC for the following reasons:

• intense difficulties with working in Unity IDE itself (it runs game "preview" without vsync, also, in "scene" mode particles appear as they are without vsync on.)

• The game will be playable at 30-50 FPS, how it will behave with forced vsync? It will turn it off and particles will start to behave weird again? (UPDATE: the correct answer it will sync to 30 FPS, obviously)

(No scripts were used in the particle systems' gameobjects, just empty GameObject with system attached).

Answer 1

This is a known bug in Unity and has been reported previously in their issue tracker. See http://issuetracker.unity3d.com/issues/shuriken-particle-system-module-limit-velocity-over-lifetime-is-fps-dependent