CloudCompare forum

Hi,

I'm tring to extrac some sections from a point cloud using the tool Cross Section-->Slices-->Contours, but I'm noting that the polyline doesn't fit well to the shape of the cloud.

What could be the problem?

I attach two screenshot.

Thank you!

Probably your slices are too thick. As all the points of the slice are projected on the same plane (in the middle of the slice), it can produce this effect when the slice thickness is big.

Hi Daniel, thank you.
I tried to reduce the thickness of the slices to 5 cm but I get the same problem. The same thing happens when I try to extract even only one contour..

I attach two screenshot

Is the gap between your contours the actual slice thickness? Because it's still huge.

Or did you use a non zero gap between the slices?

I'm setting the thickness of the slices and the space between the contours in the way show in the screenshot.

I'm sorry but the correct settings are these, with the gap fixed to zero.

Maybe it's not correct?

What does the result with these parameters look like? Can you try with a much thinner slice (e.g. 1 or 2 if the density of the cloud is sufficient) and the corresponding gap? (i.e. 9 or 8).

HI Daniel, a fundamental question to understand better. If I want extract a series of contours every 10 cm, which parameters should I set?

Thank you

Well, you simply need to set the 'Gap' parameter to the 10 cm minus the thickness of the slice.

Hm. I'm not sure to understand well. If I want extract a serie of slices and contours every 10 cm I guess to set in the "box thikness" a value of 0.10 and in the gap a value of zero? Right?