surface area calculation

[doaa]

Hello
Im researcher how can i measure the surface area of a selected part in cloud compare

[daniel]

You can try to segment the part with the scissors tool and then use the 'Tools > Fit > Facet' tool. It will fit a 'facet' element to the cloud, from which you can read the surface in its properties.

[doaa]

thank you for your answer
i want to measure the surface area of only visible traingles of stl mesh generated from ct scan images without thickness

[daniel]

Hum, if it's for a mesh, then you may have more luck with Meshlab or Blender?

[doaa]

many thank for your answer، please could you help me
i have two modeling of hand generated from ct data and photogrammetry
i want to procedure comparison between the surface area of the two modeling
what is the best way to do that

[daniel]

I would use the C2C (cloud-to-cloud) or C2M (cloud-to-mesh) tools? (see http://www.cloudcompare.org/doc/wiki/in ... #Distances)

[doaa]

thank you daniel
please could you tell me how can i export signed distances of cloud to mesh comparison to test the normality assumption in minitab software

[daniel]

Well you can test it directly by using the 'Edit > Scalar field > Fit Stat. Distrib' function (and choose the Gauss distribution). It will fit a Normal model, and you can even get the Chi2 distance in the console.

Otherwise, to export any scalar field, simply save the cloud as a text (ASCII) file. It will create a text file with X, Y Z, the scalar field values, etc. on each line. You can even choose the separator, etc.

[doaa]

Hi Daniel,
how CC calculates the surface area of mesh and point cloud?
what is the algorithm that used to calculate the surface area?

[daniel]

For a mesh it's easy, it's simply the sum of the areas of all triangles.

For the cloud, what do you mean? CC doesn't compute areas of point clouds, is it?