move point cloud to 0 0 0

[Tom van der Putte]

Hi!

I'm trying to move a point cloud to 0 0 0 to remove the connection to the original location. So I looked up some other conversations (specifically https://groups.google.com/g/lastools/c/HDwvY5Y_S0Q). First I looked up MIN X,Y,Z using lasinfo 

test_pre_offset.las:
  scale factor x y z:         0.001 0.001 0.001
  offset x y z:               559687 5716451 45
  min x y z:                  559472.577 5715866.052 42.262

  max x y z:                  563562.659 5720416.411 81.871

and then used the following command:

las2las -translate_xyz -559472 -5715866 -42 -reoffset 0 0 0 -i "test_pre_offset.las" -o "test_offset.las"

The output was:

WARNING: reoffsetting from 5.71645e+006 to 0 causes LAS integer overflow for min_y
WARNING: reoffsetting from 5.71645e+006 to 0 causes LAS integer overflow for max_y
WARNING: total of 42588575 overflows caused by '-translate_xyz -559472.000000 -5715866.000000 -42.000000 '

Lasinfo on the output file gave the expected results, but I'm not confident that the data itself is still OK, due to the warnings it gave.

test_offset.las:
  scale factor x y z:         0.001 0.001 0.001
  offset x y z:               0 0 0
  min x y z:                  0.577 0.052 0.262
  max x y z:                  4090.659 4550.411 39.871

Any tips on this one?

[Jochen Rapidlasso]

Hi Tom,

did you check what I wrote at

https://groups.google.com/g/lastools/c/t5rahApgU04

about translation and offset?

If it is still not working may support a sample and I will have a closer look...

Thanks,

Jochen @rapidlasso

[Tom van der Putte]

Hi Jochen,

Thanks for that one, but it only adds to my confusion: I understand that only translating, or only changing offsett will lead to an overflow. But I specifically moved everything to origin 0, and at the same time set the offset to 0. So that would decrease the size of coordinates right?

Or maybe the reoffset also recalculates everything again, thereby "doubling" the effect?

Regards,

Tom 

Op ma 31 okt. 2022 11:40 schreef Jochen Rapidlasso <rapid...@gmail.com>:

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[Jochen Rapidlasso]

Hi Tom,

yes, according to my doings at https://groups.google.com/g/lastools/c/t5rahApgU04: 

-reoffset put an offset into the header and recalculate the points with this offset.

Best regards,

Jochen @rapidlasso

[Tom van der Putte]

Hi Jochen,

But then the instructions from Martin in the first reference I mentioned dot not make sense (at least in my head :) ). I'll have another look at it tomorrow and maybe send a small trial section.

 Regards,

Tom 

Op ma 31 okt. 2022 20:36 schreef Jochen Rapidlasso <rapid...@gmail.com>:

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