Foam partly disappears at grid's end

[bobweb]

Hello,

I have built a ship/ocean scene, mostly according to your tutorial. For my shot I want to have a rather long tail of foam behind the ship like it is with some huge container ships. So I put in a longer halflife and outside life, but only some foam particles make it outside the grid, others seem to die at the border. Any idea why this could be the case? Since it already took days to simulate in this size I would rather not make the grid bigger. Please have a look at the preview and settings: http://www.bobfolio.de/upload/PhoenixBoatTest.zip

Thanks!
Bob

[Ivaylo Katev]

hi,
i suppose the reason is too small "outside life" parameter. it's a bit tricky, let me explain how this parameter works to understand how to prevent such situations in future.
in order to save memory the foam particles do not have separate timer for outside life, the total life is used instead. the more accurate name of this parameter should be "particle age limit outside the grid", but this is too long. in your case the particles born in front of the boat need more than 10 seconds to leave the grid, and when they do this they are killed immediately. so, to solve the problem make the outside limit bigger than the time needed to travel from the leading part of the ship to the grid exit.

[bobweb]

Ah, ok, I see, I interpreted the parameter as the absolute lifetime outside the grid. Now that you explained it further the documentation entry also makes more sense to me. May I suggest to add there that the age is still counted from birth, not from exiting the grid, just to make it more clear.
Thanks again for your fast and insightful response.
Bob

[Svetlin.Nikolov]

Updated. Please tell us whenever something else in the help file seems under-explained, we really appreciate it.