CloudCompare forum

Hello to everyone,

at first I would to thank Daniel for CloudCompare and Thomas for qFacet plugins.
I'm writing here because I'm wondering about extraction of data using the tools export facet data as CSV of qFacet plugin.
I'm a geologist and I need to extract the extact dimesion of the plane and/or facet that CC fits, I report an example to show you what I mean:

(1) when CC fits a plane, it shows the local dimesion of the plane (that I need) in the plane properties window (X: 17.8864, Y: 3.27921, Z: 0) (fig.1);

(2) then fitting a facet to the plane and extracting its parameters the CSV shows Horizontal extent :18.0424, Vertical extent: 8.52167 and Surface 52.6532 (fig.2);

(3) whereas I can undestand the value of surface, that seems to be the product of the local dimension of the plane, I cannot understand the value of Horizonal and Vertical extents, that seem to be also different from the dimension of the bounding box of the fitted entity (fig.3)

It is also possible to modify the qFacets code of the export CSV adding the information of dimension of the plane (e.g. local box dimesion in fig.1)?

I hope to be clear.
Waiting to recive some replies from you.
Your sincerely

Niccolò Menegoni

Hi,

Actually what is disturbing is probably how these 'Horizonal' and 'Vertical extents' are defined in the qFacets plugin.

You have to consider that the 'normal' (the one you must define when you export the set of facets) is the vertical direction. Then the Vertical extent is something the extent along this direction (lowest to highest point). And the 'horizontal' extent is the same but in the plane orthogonal to this normal. So depending on this normal it can have very different significations.

And if you consider the other metrics:
- the plane width and height are really the length and width of the rectangle
- the bounding-box extents are always expressed along the main directions of the current coordinate system (X, Y and Z)

Hope this helps.