Monitoring surveys

[wizzawozza]

Hi there,
First time user so apologies in advance!

I have point cloud surveys of a room of building which I have scanned a year apart and want to detect any movement in the ceilings.

First question - does the e57 data need to be unified?
Second question - the scans are on the same control grid and doesn't need further registration, how do I jump straight in and compare the two datasets?

Thanks

Warren

[daniel]

So if the 2 scans/clouds have the same coordinate system / reference, then you don't need to merge them. Just highlight both of them and then use 'Tools > Distances > Cloud/Cloud dist.' for simple unsigned distances (see https://www.cloudcompare.org/doc/wiki/i ... d_Distance) or the M3C2 plugin for more robust and signed distances (see https://www.cloudcompare.org/doc/wiki/i ... 2_(plugin)).

[wizzawozza]

Thanks for that.
And the data has to be unified, ie only compare 2 scans?

[daniel]

Ah yes, if you have more than one scan to act as reference or compared entities, yes.