Control Cleaning noise a from a free-shaped cloud

[Rzok]

Hi, i tried to used a noice reduction filter, and set the noise filter with radius 0.010 why it random cleaning a points from the same cloud. I mean i used this many times with the same parameters at orignal cloud and the number and the points was diffrent. How this tool actually works?

[Rzok]

other screen of cloud

[daniel]

Can you detail your exact workflow?

[Rzok]

i imported a original data cloud from CMM and a i used a Noise reduction filter with parameters radius sphere 0.01 mm and thats all.

[Rzok]

The problem is when i import a same cloud not the same points are hidden by the same parameters u understand?

[daniel]

The exact same cloud?

And are you referring to the 'SOR filter' or the more complex 'Noise filter'? (I guess it's the second one, but I prefer to double check)

[Rzok]

yes the exact same cloud and i used a noise filter not sor filter

[daniel]

Ok, so I was able to reproduce this effect on my side... But I still don't know why it's not perfectly reproducible yet... I'll have to investigate more.

[Rzok]

Hi Daniel again, can you help me explaining this noise filter? Since i got my points cloud i need to reduce the noises with the control way, and uhm my cloud have 625 points and my professor says that error of CMM its 5 um and the roughness of surface is 10 um and according to this informations Professor says the number of the points detected as a noises should be like a 30 +/-. But the program deleting about 8 to 10 points. How exactly set the parameters to get a cloud filtered like that? Im doing this to get my master's degree and need help :<

[daniel]

Well, first, this tool is clearly not meant to be used on such a low density cloud.

It's principle is to fit a local plane by considering the neighbors of each point (https://www.cloudcompare.org/doc/wiki/i ... ise_filter). The parameters at the top of the dialog are used to define the 'neighbors'.

Then the distance between the plane and the central point is compared to the distance of the other points to the plane. You can decide to clean the points based on this distance ('Absolute') or based on the average distance plus a given number of times the standard deviation (1 by default).