Sergey Sharybin
d2f3378249
The issue was caused by dependency graph resetting particles when evaluating copy-on-write version of object. Solved by only doing reset from dependency graph on user edits. Other issue was caused by modifier itself trying to compare topology and reset particles when number of vertices or faces changed. This isn't reliable, since topology might change even with same number of elements. But also, since copy-on-written object initially always have those fields zero-ed the reset was happening on every F12. The latter issue is solved by moving reset from modifier stack to places where we exit edit/paint modes which might be changing topology. There is still weird issue of particles generated at some weird location after tapping tab twice, but this is not a new issue in 2.8 branch and is to be looked separately.