M3C2 distance_Core points

[GranitB]

Hi,

I've been working on CloudCompare for my internship to compare the distance result M3C2. The purpose is to compare 2 points clouds of a cave at 2 different dates.
My question is: If Cloud 1 is reference cloud and Cloud 2 the compared cloud. For compiling the core points, which cloud should I use Cloud 1 or 2?
The other question is: From outputs of M3C2 you get STD cloud 1 and STD cloud 2, what does STD mean?

Thanks

[daniel]

1) M3C2 seaches for each point of cloud#1 their correspondance in cloud #2 along cloud#1 normals (and inside a cylinder). Therefore it's hard to say which one is the reference and which one is the compared cloud. It would be more to say that we track the changes of cloud #1 in cloud #2 (therefore could #1 is generally the oldest one? Therefore it might be considered as the reference? Not sure ;).

2) STD = standard deviation

[GranitB]

Thanks for your reply! :)