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Author Topic: Crash - how much Ram is recommended? I have 20 gigs  (Read 15500 times)

Brit

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Crash - how much Ram is recommended? I have 20 gigs
« on: November 12, 2014, 12:25:38 AM »
Hello, I just made a dense cloud of a Soviet monument stele in Berlin. It took a couple hours, but all was fine when complete. However I tried to make a medium mesh (4 million faces) from the cloud. When I came back after 10 hours of processing the mesh in the morning it was at 10% and was using most of my  20 Ram of memory. It couldn't handle the processing. I have never seen that before today. I tried for about 1/2 hour to cancel the processing with no success, and then used the Task Manager to close the program, losing all previous processing. What would you recommend – get more ram, try chunks (whatever they are..?) using my laptop as well, lower the mesh quality?
« Last Edit: November 12, 2014, 06:32:43 AM by Brit »

Alexey Pasumansky

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #1 on: November 12, 2014, 12:37:55 AM »
Hello Brit,

Please refer to the approximate memory consumption peaks mentioned in the following document depending on the number/resolution of images and processing settins used:
http://www.agisoft.com/pdf/tips_and_tricks/PhotoScan_Memory_Requirements.pdf

So actually, the quality of the dense cloud is important and not the number of polygons specified in the Build Model dialog.

Could you plase specify the number of images and their resolution? Probably you've also have the log file saved related to the process?

I can suggest to lower the dense cloud resolution as it seems easier than installing more RAM. Also please check that the bounding box is shrink up to the monumnet and doesn't cover unwanted background.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Brit

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #2 on: November 12, 2014, 07:30:31 AM »
I tried again and the point cloud came out OK (at 75 million points- and I saved it this time), but when I tried to "build mesh"... even at a low poly setting it goes to 5%, and then the RAM immediately goes up to over 19 megs and it seems to stop there and freeze.

Do you mean I should perhaps build the dense cloud on "medium" instead of the default "high"? Would playing with the gradual selection and re projection error settings help?

I had 99 photos at 18 megapixlas each. I'm not sure what the Height-field mode vs Arbitrary mode means on the link you provided.

Alexey Pasumansky

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #3 on: November 12, 2014, 10:38:01 AM »
Hello Brit,

Yes, I suggest to use Medium dense cloud quality instead of High (but you can keep High-quality project, if you wish you can send it to us and we'll check the memory consumption peak and send back the resulting project). The number of polygons in the target model doesn't matter, as at first PhotoScan generates as much polygons as possible (in Arbitrary mode) and then decimates the model.

Also I can suggest to turn on the log file (in PhotoScan Preferences window) or enable Console pane view to see the auxillary information on screen, but according to task manager, commit is already 28 GB.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Brit

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #4 on: November 13, 2014, 04:19:12 AM »
I am adding another 12 gigs of RAM tomorrow. that should help.

Alexey Pasumansky

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #5 on: November 13, 2014, 05:20:13 AM »
Ok, let us know if there are still any problems with higher amount of RAM.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Brit

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #6 on: November 13, 2014, 07:11:12 AM »
The medium setting is not too bad.

Now I need to figure out how to "close" it for printing with Meshmixer and 3D Studio. I will attach an image with a "porcelain" material mapped on it instead of the photo bitmap to show how accurate it is.

...I have put a couple of these printed scans in this exhibition http://www.sanderson.co.nz/Exhibition/350/Brit-Bunkley/Social-Realism.aspx

Alexey Pasumansky

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #7 on: November 13, 2014, 07:53:36 AM »
Hello Brit,

You can try generating mesh using Extrapolated geometry as it should produce "water-tight" model.
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Alexey Pasumansky,
Agisoft LLC

igor73

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #8 on: November 13, 2014, 07:23:53 PM »
Is Extrapolated geometry a new feature in 1.1?  Only on pro version?  Never seen the option before.  Sounds interesting if photoscan can make watertight meshes from scratch. 


igor73

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #9 on: November 13, 2014, 07:42:14 PM »
Ohh, extrapolated is the default option when generating mesh right?

Alexey Pasumansky

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #10 on: November 13, 2014, 07:53:08 PM »
Hello igor73,

Extrapolated option is available since version 1.0. However, the default option is "Enabled (default)".
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Alexey Pasumansky,
Agisoft LLC

igor73

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #11 on: November 13, 2014, 08:51:37 PM »
So extrapolated option will try to fill holes more than the default enabled option?  Is that the only difference? 

Alexey Pasumansky

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #12 on: November 13, 2014, 08:53:16 PM »
Hello igor73,

Extrapolated option in Arbitrary mode will produce water-tight model, as you've already mentioned it. In Height Field mode the serface will not have any holes and will be extended to the bounding box limits.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Brit

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #13 on: December 01, 2014, 04:21:48 AM »
I built a new system with 32 gigs ram. It wa processing OK with the hi-def cloud... but then got stuck at "6% done" for a long time...at 24 gigs of ram -but the CPU was only working at 4-5%. I canceled the processing, but it wouldn't cancel so I forced the program to close. The whole system had crawled to a stand still. For a 1/2 hour after closing, my computer still wouldn't allow other programs to start and kept crashing windows Explorer. Even task manger crashed. I'll test my ram as soon as I can with memtest86
« Last Edit: December 01, 2014, 04:42:05 AM by Brit »

Marcel

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Re: Crash - how much Ram is recommended? I have 20 gigs
« Reply #14 on: December 01, 2014, 12:26:48 PM »
What is the size of your Dense Point Cloud?

Photoscan will always build the mesh at maximum resolution, and then Decimate the mesh back to the setting you chose. That means if your point cloud is 60 million points, Photoscan might make (for example) a 100 million polygon mesh before Decimating it back to 4 million polygons.

The only solutions right now are:
-  re-build the Dense Cloud at a lower quality setting
- add even more RAM

A way to decimate the Dense Point Cloud would be very useful (especially if the reduction in points would be done in a smart way), but currently this is not available.