Thanks for the fast response. I tried again and it seems like it still works. My fail was, that i didnt simulate the particle into world space.
But i still have one minor issue. If the velocity of the object is 0 the vertex offset is going to shoot it into nothingness. Basicly its invisible for the eye, cause its gone somewhere far of. if the object has an velocity of 0.00001 or something into a direction than the object is visible again, but it seems on 0 its gone. Do you know how i could fix that?
EDIT: u have to expand the picture to fully see it
Here u can see that the Particel is still there cause the colliderbox is still visualized. But it disappears.
EDIT 2: Setting the startSpeed to 0 will let the particle be not visible. even if u apply gravity to them