CloudCompare forum

Hello
Thank you for this excellent program.
I have been studying this CloudCompare recently.

First, I have been trying to understand the result of C2C distance.
I did 2 trials with two couple of simple cloud files like below.

About this test file.
1st : Each test file has only one points.
2st : Each test file has only two points.

My question is
1. why the result is different between the below 2 trials.
2. In the below 2st, why the value was calculated like below not distance(x) = 3 like 1st trial.
( Actually, the value of distance(x) = 3 is very reasonable to me. )

Thank you for reading my question.

1st *********************************************************************************************************************************
Each file has only 1 row. and only x value is different( difference is 3 )
compared
X y z schalar
-6.09350348 -1.84549356 93.28673553 93.286736

Reference
-9.09350348 -1.84549356 93.28673553 93.286736

C2C Distance Result is below
X y z schalar distances_(Z) distances C2C distances_(X) distances_(Y)
-6.09350348 -1.84549356 93.28673553 93.286736 0.000000 3.000000 3.000000 0.000000


2st **********************************************************************************************************************************
Each file has only 2 rows. and only x value is different(the difference is 3 )

compared
X y z schalar
-6.09350348 -1.84549356 93.28673553 93.286736
-6.17963266 -1.86526489 93.28673553 93.286736

Reference
-9.09350348 -1.84549356 93.28673553 93.286736
-6.17963266 -1.86526489 93.28673553 93.286736

C2C Distance Result is below
X y z schalar distances_(Z) distances C2C distances_(X) distances_(Y)
-6.09350348 -1.84549356 93.28673553 93.286736 0.000000 0.088369 0.086129 0.019771
-6.17963266 -1.86526489 93.28673553 93.286736 0.000000 0.000000 0.000000 0.000000

I am confused why the result of distance is not "distances_(X) = 3.0" like the above 1st trial.
In the two data, only one "X" value of the first point is different with the difference 3.

Thank you.

This is because C2C will measure to each nearest point pair meaning the two points will both measure against the same 1 point that is near by (as opposed to the one that is 3" away)

Hello WargodHernandez

Thank you for your reply.