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Author Topic: Gradual selection still quite slow (v1.6.5 - 386M tie points, ~5-8+h)  (Read 2304 times)

andyroo

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I'm running gradual selection on a 386 million point cloud (from 82,000 cameras) and the initial "Analyzing Point Cloud" step after I select which parameter to use and before I select the gradual selection threshold is taking quite a while. It looks like it's going to be about 5-6 hours on my workstation (80% done @ 4h), and it's going to take > 8 hours on a HPC login node with slower RAM. Wondering if there's anything I can do to speed this up (headless? 1.7.x?).

On the workstation (Threadripper 3960x with 256GB 3000MHz RAM and 2x RTX 2080 Super GPUs) it appears to be using minimal CPU resources (maybe a single core, resource monitor says ~4% CPU) and  it's using about 60GB of 256GB total RAM (total system usage is about 72GB).

Alexey Pasumansky

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Re: Gradual selection still quite slow (v1.6.5 - 386M tie points, ~5-8+h)
« Reply #1 on: February 13, 2021, 07:35:45 PM »
Hello Andy,

Is it the same issue reported by you in November:
https://www.agisoft.com/forum/index.php?topic=11487

There were some optimizations in the gradual selection process related to the tie points selection, which should give a considerable performance boost for this task. So if you have a chance to check the same procedure in 1.7.1 version, please report, whether it work significantly faster now.
Best regards,
Alexey Pasumansky,
Agisoft LLC

andyroo

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Re: Gradual selection still quite slow (v1.6.5 - 386M tie points, ~5-8+h)
« Reply #2 on: February 16, 2021, 08:57:18 PM »
Thank you Alexey. I will look at gradual selection speed in 1.7.x. I was holding off because of the depth maps issue but I can turn on the tweak to use 1.6.x depths maps method.

andyroo

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Re: Gradual selection still quite slow (v1.6.5 - 386M tie points, ~5-8+h)
« Reply #3 on: February 16, 2021, 10:34:34 PM »
...There were some optimizations in the gradual selection process related to the tie points selection, which should give a considerable performance boost for this task. So if you have a chance to check the same procedure in 1.7.1 version, please report, whether it work significantly faster now.

Holey Moley!

"considerable performance boost" No kidding! Gradual selection "Analyzing points" step went from ~4300s to 243s from 1.6.5 to 1.7.1! That's some pretty nice algorithm optimization - like a 95% speed-up! Gradual selection point selection looks to be about 18x faster, cutting the overall optimization time in half if the rest of the optimization process stayed constant (testing now)

Nice job Agisoft, and THANK YOU for being so responsive  ;D  ;D