every 15th frame is different on the same machine

[lander]

I made a very basic sim of a car burnout.
But the 15th frame in the sim is repeatedly different and much bigger in filesize.
I include frame 13, 14, 15. (max starts at 0) same thing happens on frame 29, 44.

What could be the cause of this?

I use Max 2015 and latest official build of PhoenixFD

[Ivaylo Katev]

by default every 15 frame contains restore info, but i see such a behavior for first time!
perhaps we will need the scene to investigate the problem

[lander]

ok I have sent scene and sim with WeTransfer to phoenix@chaosgroup.com

[Svetlin.Nikolov]

Hi, we tested with the official phoenix 2.2 and vray 3.07, using the cache files you attached. We could not reproduce the difference in rendering of frame 14 as compared to the other vray atmosphere elements. Can you try a latest vray and phoenix nightly as tell us if you still have the issue?

Also, as Ivaylo said, the file sizes are normal - each 15th frame contains backup info so you can restore the simulation later if you want to prolong it. You can change the interval from 15 to whatever value suits your needs from the Output panel - "Backup interval". If you want to turn it off, set it to 0.

As a side note, the scene is over-exposed and does not match the shots you attached, so this does not help either...

[lander]

Hi, I tested with the latest nightly build and it renders fine.
Thanks

Now I have a different problem. I'm trying to create a lavaflow but when I set the scene scale to 1 unit = 1 Meter the liquid never starts to flow it just keeps growing lika a baloon. As I change the scene scale to cm it works alot better.
I tried to change the Scene scale from .01 to 100 in the FD but that had no effect.

[Ivaylo Katev]

i suppose the simulator size is too big and the movement produced by the gravity is smashed by the side effects of the simulation. if really this is the reason, you can try the slow moving advection, it may help.
are you sure that the produced movement is really smaller than the expected one? i mean for 30 frames you will have less than 5 meters movement, that may be too smal for your simulator size.

[lander]

I'll try the slow moving advection.
Thanks