I have run into this peculiar behavior in 2.69, is it just me? I create a plane, add a loop cut, add a particle system (hair, advanced), set the number to 2000 and children to 60 interpolated. When I render it, the process gets stuck on “Synchronizing object” for a long time. This doesn’t happen in 2.68a, or if I uncheck the “Random” (Emit in random order of elements) option under Emission, or if I remove the loop cut (and have a simple plane with 4 vertices). Or (and here comes the tricky part) if I increase the number of children to somewhere around 100.
If I increase the number of children a little more, the problem returns at around 130 and it gets exponentially worse timewise.
Different shapes go bonkers at different numbers (a cube is fine at 60, but becomes slow at 100), but it doesn’t depend on visibility or how the object is rotated.
I rendered on CPU, I tried 2.69 RC2 and RC3:
OS: OS X 10.9 Mavericks
Processor: 2,8 GHz Intel Core 2 Duo
Memory: 4 GB
BA doesn’t allow the .blend upload, but: http://www.pasteall.org/blend/24880
Could someone confirm that this is indeed a real issue?
My results with
- 2000x60 particles, Random unchecked: 7.47sec
- 2000x60 particles, Random checked: 37.93sec
- 2000x100 particles, Random checked: 9.01sec
(Of course it gets more annoying in more complex scenes. There wasn’t any meaningful difference in time between the “Random” checked or unchecked in 2.68, and the option is checked by default, so it’s not some hidden, never used feature.)