CloudCompare forum

Hi there!

First of all i need a command line solution for this. I have an e57 which cannot be exported with the default las/laz precision some kind of very small precision... Like 10^-9. My cloud is in the 40-70m range.

How can i set las/laz export precision with command line to a normal precision like 0.1-1 mm

Or why is it calculating wrong precision in the first place? I have not came across with this problem before, maybe because previosly i merged several clouds? It changes something?

By default, CC has always used the maximum theoretical precision for LAS files since:

• we don't have any information about the scale and nature of the cloud (not all users use the LAS format to save real life clouds in millimeters...)
• it has no impact on the file size if you save the cloud in the LAS format (however it has a big impact on the file size if you save as LAZ...)

To overcome this issue, for some time now CC will remember the 'LAS scale' and 'LAS shift' associated to the cloud if it was loaded from a LAS file. And it will try to reuse this information at export time. And even if you merge several clouds, as long as one of them came from a LAS file, this information should be preserved and used at export time.

And you can also set this information manually with the graphical version.

But sadly for now there's no way to set the output precision via the command line...

That is the whole point of command line which i don't have to open manually...
I have like 500-800 scan position per project each with 10-20 million point.

I don't really care about the file sizes.. I already use laz, which is way more compact my problem is that gdal throw an overflow issue during write time...

For now i changed my script to use laszip, and lasoptimize... But the subsampling is way more better in cc.

I'm confused. You don't care about the file size, then why don't you keep the best precision (i.e. CC's default behavior) and use LAS format?

Otherwise, it would definitely be possible to add a suboption to the command line. But as usual in an open source project... someone has to do it ;)

Sorry you misunderstood i care about the file size to use laz but don't care if its 25 mb or 24mb which is not that much of a difference (structured e57 is 250m with images). This is the difference with different laz precision i would do that extension but not right now i don't have time to do that.