Point segmentation based on primitives

[Ingsayyad]

How can I segment my points based on geometric primitives.

1.All points lying above or below or on the plane
2: All points inside or outside or on the cylinder surface etc.

Any tip/trick.

[daniel]

Well, if the primtive is already in place, you can simply compute the distances between the point cloud and the primitive (with Tools > Distances > Cloud/Mesh distances - as a primitive is a particular mesh in fact).

Then use the 'Edit > Scalar values > Filter by value' method to remove the points with distance below or above a certain threshold (depending on what you want). The convention is that a point 'inside' a mesh will have a negative distance.

[Ingsayyad]

I do use this option but problem is that I lose color information of point cloud and end up only with scalar factor. I know I can do color interpolation fro original point cloud but It took so much time. Is there any way that I do not lose color info.

[orinn]

Cloud Compare retains the color information. Either it switching the display off of RGB and onto Scalar Fields or under scalar fields you can select your intensity values and choose the original values instead of the cloud to mesh computed results.