Sergey Sharybin
e925c20f2f
Fix T61289: Emitting particles from instances not working properly The first issue has been re-introduced by a code which was dealing with missing hair after opening the file. That was re-setting all particle systems all the time because modifier flags were not copied back to original. This made every modifier run to be seem as an initial file open. Now we copy flags back to an original modifier. But also we are trying to not do any resets unless needed in that case. This way we can preserve in-memory caches. Other part of the change is related on re-setting particle system if number of mesh elements changed. But we only do it if the modifier has been already evaluated once.