Cloud-To-Cloud Issue

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AdamB
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Joined: Mon Nov 06, 2017 10:00 pm

Re: Cloud-To-Cloud Issue

Post by AdamB »

daniel wrote:Hum, with the E57 files, I can't reproduce the issue. I get the same result in the GUI and the command line mode.

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CloudCompare.exe -silent -auto_save off -O Compared_201701031_Outside.e57 -O Reference_201701027_Outside.e57 -C2C_DIST -max_dist 0.5 -C_EXPORT_FMT E57 -no_timestamp -save_clouds
I guess the issue do come from the LAS files. Can you send them to me?

Note: regarding your command line, it would be more efficient to use the '-C_EXPORT_FMT E57 -no_timestamp' options before the -C2C_DIST option, and remove the '-auto_save off' and '-save_clouds' options. This way you'll get only one file (the compared cloud). Apart if you want both files as E57 files of course ;)
Hey Daniel, sorry it took so long. I have uploaded the LAS files to that same Dropbox folder. From more testing with 2.9.1 command line, I've learned the following:
  • Any number of uses of Global_shift AUTO breaks the cloud-to-cloud comparison when using LAS files

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    CloudCompare.exe -silent -O -GLOBAL_SHIFT AUTO Compared_201701031_Outside.las -O -GLOBAL_SHIFT AUTO Reference_201701027_Outside.las -C_EXPORT_FMT E57 -no_timestamp -C2C_DIST -max_dist 0.5
    Or

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    CloudCompare.exe -silent -O -GLOBAL_SHIFT AUTO Compared_201701031_Outside.las -O Reference_201701027_Outside.las -C_EXPORT_FMT E57 -no_timestamp -C2C_DIST -max_dist 0.5
    Or

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    CloudCompare.exe -silent -O Compared_201701031_Outside.las -O -GLOBAL_SHIFT AUTO Reference_201701027_Outside.las -C_EXPORT_FMT E57 -no_timestamp -C2C_DIST -max_dist 0.5
  • Using default Global Shift & Scale triggering limits, cloud-to-cloud comparison works fine LAS files

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    CloudCompare.exe -silent -O Compared_201701031_Outside.las -O Reference_201701027_Outside.las -C_EXPORT_FMT E57 -no_timestamp -C2C_DIST -max_dist 0.5
I have used the following Global Shift & Scale triggering limits, which I believe are the default on a clean install:

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Max absolute coordinate: 10^6
Max entity diagonal: 10^4
daniel
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Re: Cloud-To-Cloud Issue

Post by daniel »

Indeed, it seems that when dealing with LAS files, the 'Auto' global scale is not that smart. I'll have to fix this.

Meanwhile, I think an easy solution in your case is to set the global shift manually to (0, 0, 0):

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-GLOBAL_SHIFT 0 0 0
You shouldn't have any accuracy issue as you deal with TLS clouds. And the LAS shift (which is used by CC as a default Global Shift for LAS files) is very small in the examples you sent me.
Daniel, CloudCompare admin
daniel
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Re: Cloud-To-Cloud Issue

Post by daniel »

Ok, it's fixed in the code (it will be available in the next release). Meanwhile a (0, 0, 0) global shift should do the trick.
Daniel, CloudCompare admin
daniel
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Re: Cloud-To-Cloud Issue

Post by daniel »

Ok, it's fixed in the code (it will be available in the next release). Meanwhile a (0, 0, 0) global shift should do the trick.
Daniel, CloudCompare admin
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Re: Cloud-To-Cloud Issue

Post by daniel »

For the records the online 2.10.alpha version has just been updated.
Daniel, CloudCompare admin
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