Large delay between renders when Batch Rendering

[Parmenides]

I have a scene that normally renders in Maya in about 9 seconds. But if I batch render, the files take 2 minutes to render.  It's 10x faster to render in Maya, advance a frame and save the file.  Why is there such a difference in time between the 3 types of rendering? 

The log file says:

Performance warnings:
WARNING | Rendering CPU utilization was only 24%. Your render may be bound by a single threaded process or I/O.
WARNING | Scene creation was a significant amount of total time (83%). Consider optimizing this process first.

[lee_griggs]

Do you have any more details about the scene? Textures, geo, etc? A more detailed log file would also be useful.

[Parmenides]

I have also increased the textures max cache from 4096 to 8192 in the Arnold render settings and moved all the textures to a SSD. I have no idea how to fix the single threaded process issue. Even after the file renders, it just sits there for awhile. 

[lee_griggs]

How large are the textures? Maybe it is taking time to convert the textures to .tx. Can you provide a detailed log like below? The zip file is empty btw. Do you have a simplified scene that demonstrates the issue?

[Stephen.Blair]

The zip has a partial log for an interactive render, so we can't tell much from that. Too much is missing. For batch renders, I would get the MayaRender log:

~/Library/Logs/Maya/mayaRender.log

The peak texture cache memory is 800MB, so there's no need to increase the cache size.

[Parmenides]

Hello, the MayaRender.log is 800MB.  I have attached another log of a batch render of just one frame. 

[Stephen.Blair]

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@Parmenides wrote:

Hello, the MayaRender.log is 800MB.  I have attached another log of a batch render of just one frame. 

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You can compress it. Or delete it, or rename it, and let Maya create a new one.

I can't tell exactly what happens between frames 140 and 141 (Archive.zip contains two log files, and the file names indicate frames 140 and 141).

Looks like the Maya takes at least 2 minutes 15 seconds to start up and load the scene, because the first line in the Arnold log is time-stamped 00:02:15

[Parmenides]

Ok, I renamed the log and rendered 3 frames via batch render. Hopefully this will help. 

[Parmenides]

From what I can figure is that doing a simple render from within Maya does a 'scene creation' once and not on subsequent renders. Batch Render and Render Sequence do the 'scene creation' every time which is adding the 2.5 minutes to each frame. Is there a way to disable this from happening every frame?   Especially since it only uses 1 processor out of 28. The Activity viewer show almost nothing happening during this delay. 

[Parmenides]

Any help on this would be appreciated. It means the difference between hours and days when rendering. Thanks. 

[Stephen.Blair]

A batch render will export each frame individually. The IPR approach of updating an existing scene in memory won't work reliably for all the different types of production scenes.

Your MayaRender log was not very verbose. We can see 2+ minutes for the Arnold scene export, but no details.
If the log verbosity was set to Info, we should see more. And you could enable MtoA Translation Info too.

Exporting Arnold Scene...
Updating Arnold Scene...
00:02:17 15456MB         | log started Wed Jun 21 08:43:57 2023
00:02:17 15456MB         | Arnold 7.2.2.0 [40c92ac1] darwin x86_64 clang-15.0.7 oiio-2.4.1 osl-1.12.9 vdb-7.1.1 adlsdk-7.4.2.47 clmhub-3.1.1.43 rlm-14.2.5 2023/06/05 17:18:19
00:02:17 15456MB         | host application: MtoA 5.3.2 a59426fb (fix-5.3.2) Maya 2024
00:02:17 15456MB         | running on MacPro-2019-Jupiter-402.local, pid=60140
00:02:17 15456MB         |  1 x Intel(R) Xeon(R) W-3275M CPU @ 2.50GHz (28 cores, 56 logical) with 262144MB
00:02:17 15456MB         |  Mac OS 13.4.0, Darwin kernel 22.5.0
00:02:17 15456MB         |  soft limit for open files is set at 10238
00:02:17 15456MB         |  
Exporting Arnold Scene...
Updating Arnold Scene...
00:04:41 18514MB         |  log started Wed Jun 21 08:46:21 2023
00:04:41 18514MB         |  Arnold 7.2.2.0 [40c92ac1] darwin x86_64 clang-15.0.7 oiio-2.4.1 osl-1.12.9 vdb-7.1.1 adlsdk-7.4.2.47 clmhub-3.1.1.43 rlm-14.2.5 2023/06/05 17:18:19
00:04:41 18514MB         |  host application: MtoA 5.3.2 a59426fb (fix-5.3.2) Maya 2024
00:04:41 18514MB         |  running on MacPro-2019-Jupiter-402.local, pid=60140
00:04:41 18514MB         |   1 x Intel(R) Xeon(R) W-3275M CPU @ 2.50GHz (28 cores, 56 logical) with 262144MB
00:04:41 18514MB         |   Mac OS 13.4.0, Darwin kernel 22.5.0
00:04:41 18514MB         |   soft limit for open files is set at 10238
00:04:41 18514MB         |   
Exporting Arnold Scene...
Updating Arnold Scene...

 
There's not much more I can tell from the logs so far. If you want to send me your scene, I'll test it (I wouldn't need the textures).

[Parmenides]

Thanks Stephen. I guess I just need to write a script to render/save/advance until I can figure this issue out. I sent you a private message with the project link.