resim extremely slow or frozen

[ttdww]

Have a radial ground dust sim - basic setup, emitting from textures. Sims as expected; grows to about 9min/frame. Attempt at a resim set to 1.0 (2x the detail) never shows progress message, have let run for up to 2 hours, expected ram is gobbled, chugs at 4% cpu, finally just have to kill the process. Have tried all 3 modes of Wavelet. 3ds 2019, win7, pfd 3.12 / 20181017. 'Other' simulators work as expected - machine is a workhorse and stable. Known issue for this version?

Scene file attached. Thanks very much!
(Setup to resim but preview cache is turned off.)

[Svetlin.Nikolov]

Hey,

Thanks for the scene! I don't see similar sounding issues in the changelogs (https://docs.chaosgroup.com/display/...on+Change+Logs) so will try to reproduce it here with 3.12.

Could be fixed along with some other issues, it's a version from 2 years ago, but in case it's still present, gotta fix it.

Is it possible to update to the latest 3.14 nightly? https://nightlies.chaosgroup.com/#/phoenix3max/20201021

Cheers!

[tashko.zashev]

Hi,

The Grid resolution becomes quite big at the resim stage, with base sim 77million, the resim goes to 622 million cells. What is the amount of RAM memory installed on the machine ?

[ttdww]

Hi and thanks for all that feedback. 192GB ram, T7600 Dell e5-2680, 2.7ghz 2x8core, 32 threads. Probably should have mentioned that 'gobbled' didn't mean maxed. Can't recall exactly what it jumped to for WT freeze. About 50-60GB I think?

Tonight running a full base sim at equivalent to wavelet spacing. It'll be slow but will look good for res needed. Would be great to have wavelet working for future large sims of course. Will also try 3.14.

[Svetlin.Nikolov]

Oh yes, this should be enough. We'll keep digging and will ping you when we know more...

[ttdww]

Awesome. Thanks!

[tashko.zashev]

Looks like the Noise map is doing weird things in this setup and the simulation time is increased a lot. My tests shows 4min per frame (Grid 77million/ no resim) and 50sec without Noise map and stable CPU utilizaton.
You can replace the Max Noise from the Mix map used as a Source texture with V-RayNoiseTex and adjust its parameters to match the original one, which seems to work better, this is until we manage to find what is happening.

[Svetlin.Nikolov]

Yess, looks like there is hope for speeding it up even with the current texture setup, will keep you posted.

[ttdww]

...You can replace the Max Noise from the Mix map used as a Source texture with V-RayNoiseTex

Looks like I don't have that in this version of VR unfortunately.

[ttdww]

Yess, looks like there is hope for speeding it up even with the current texture setup, will keep you posted.

Sounds great - looking forward to it. My raw base sim only got to frame 3 overnight lol. I guess this won't work. Going to start a new thread to also ask about something else also. Thanks everyone!

[Svetlin.Nikolov]

Ah yes, the V-Ray noise tex is only in V-Ray 5. It's better optimized and multithreaded than the standard or the osl noise

[ttdww]

Multi-threaded sounds great. I fellback from v4, but maybe 5 will work for me. Thx for the heads up.

[tashko.zashev]

Looks like I don't have that in this version of VR unfortunately.

Its available in V-Ray Next

[Svetlin.Nikolov]

Yup, sorry, my bad, should have double checked

[Svetlin.Nikolov]

Alrighty, so the speedup change is already in today's Phoenix 4 nightlies.

Fortunately this one is very easy to port to Phoenix 3, so will pick it there as well. It will be in tomorrow's Phoenix 3 nightlies.

Please ping us when you have the chance to check it