CPU usage remains very high after rendering locally, even worse with multiple sims, even worse with foam

Phoenix Phoenix :: Issues
1

Hello all,

I have noticed a problem that occurs when I am using Phoenix. After rendering an image locally, the CPU percentage remains high after rendering is complete. This is compounded when there are multiple simulators in the scene (even more so if there is foam).

I can return my CPU usage to normal by resetting Max, or closing the scene, or deleting the Phoenix grids and running a garbage collection (typing gc() into the listener), but unless this is done, the CPUs never go down.

For projects where I only need a single simulator, this is manageable (a single ship traveling through the ocean, a single fountain shooting out water, etc).

For projects where there are multiple simulators in one scene, this makes it impossible to render locally. (Rendering over backburner seems to work)

I created a simple scene to show what is happening. I created 2 ship-like objects that are traveling forward, and 1 ball that falls and splashes. In each case, I used the PhoenixFD toolbar button “Setup an ocean sim for the selected objects” (minor adjustments, mainly just making the grids the same size and resolution).

Here it is simmed, but I haven’t rendered yet (average CPU usage around 10%):

Phoenix-CPU-UsageBeforeRender.jpg
Phoenix-CPU-UsageBeforeRender.jpg1442×792 298 KB

And here it is if I render just 1 sim (average CPU usage has jumped to 57% and stays there after rendering completes):

Phoenix-CPU-UsageAfterRendering1-sim.jpg
Phoenix-CPU-UsageAfterRendering1-sim.jpg1442×792 299 KB

And here it is after rendering 2 simulators (CPU remains around 92% after rendering completes):

Phoenix-CPU-UsageAfterRendering2-sims.jpg
Phoenix-CPU-UsageAfterRendering2-sims.jpg1442×792 285 KB

If I try to render all 3 simulators, the CPUs spike up to 100 percent and the rendering process gets stuck here:

Phoenix-CPU-UsageFreezeRendering3-sims.jpg
Phoenix-CPU-UsageFreezeRendering3-sims.jpg1442×792 295 KB

The same thing happens if I try to render a sim that has no foam, but the effect is greatly diminished. When I have rendered with all 3 simulators, but no foam, the CPUs remain around 63% after rendering completes.

I have tried turning off the preview in case it was the cause, but it didn’t make a difference (not sure if there is a better way to disable the preview):

Preview.jpg
Preview.jpg367×876 56.7 KB

Has anyone else experienced this? Does anyone have a solution? I can’t really find any discussion of this phenomenon, aside from a brief mention of CPU spikes relating to GPU previews, but it didn’t help me.

Please advise.

Thanks.

2

Which Phoenix’s version do you use?

3

Ya. Me have this half a year. Random 100%. Everywhere, even in maya.

4

I am using Phoenix 3.04.00, but this is something I have noticed in previous builds too. I can’t remember which build I first noticed it in, but I want to say 3. It coincided with being unable to use instanced grids anymore, I recall that.

5

I want to mention that we’re working on that issue and would need some time because it’s a tricky one.

6

Thank you George. Do you have an alternate recommended procedure for locally rendering a scene that has several different fluid sims at once? I supposed it could be rendered in different passes and eventually composited together, but if that’s avoidable I prefer to avoid it.

7

I have noticed the same issue too.
After rendering a scene with phoenix, only one grid, simple liquid, no foam or splashes, rendered locally, the CPU stayed at around 75% usage. Only way to get it back to normal was closing 3dsmax. Phoenix 3.04.00 | 3dsmax 2017

8

Hi,

what’s your system configuration?

9

We managed to reproduce the issue and I hope we’ll have a fix soon.

Thank you,

10

Dual Xeon E5-2680 v2 | 32GB RAM

11

Dual Xeon e5-2680 v3 2.5 GHz, 64 GB ram

12

Hello,

The issue should be fixed in the latest nightly builds. If you download one from today it should work correctly.

13

Fantastic! I can’t wait to try it out!

14

The issue is indeed fixed! Thank you so much!

15

I have noticed this is also an issue for VrayVolumeGrids. CPU usage will remain high after rendering. I will make a post in the vray category about this as well.

16

Yup, they use the same code. I integrated this into the stable nightlies of V-Ray for Max and it should be in the next official release and in today’s nightly, if you have access: Chaos

Cheers and thanks for helping us catch this!

17

hi. we are planning to get i9 with 10 cores Do you know if xeons like yours are a better option as far as simulations? Thank you

18

having this problem on dual xeon setup
one CPU hangs at 98% ish requiring starting max again

the nightlies i used to have access to have gone now? can only see blender …?

considering getting a single CPU for simulating, these xeons dont seem very good despite having SSD in RAID 0 as a drive to write and read from…

19

Hey,

The fix is in the nightlies. If you don’t see them, drop mail to support with your user name and they will see what’s wrong :slight_smile:

Cheers!

20

thanks! email sent