Fill gaps in a point cloud of a cave.

[christian077]

Hi. I've been working of this point cloud of a huge cave, which consists of a great shell, and I've segmented the cloud in slices of approximately 50 cm. The inner part of the cave is completely hollow, so I'm basically handling with its external surface. So, I would like to export some images of these slices, but here comes the problem. There are some gaps in the point cloud due to the acquisition and the magnitude of the cave. Technically, there's no problem for the study, but visually, it's not ideal. So I was wondering if there's a way I can fill these gaps in the "shell". I just need to fill these gaps of the perimeter of the cave, maybe joining the near points, but keeping the inner part as a hollow surface. Does anyone know how can I do that?

[daniel]

Two options would be to:
- mesh the shell (with Poisson Surface reconstruction for instance) and then slice the mesh (you can even sample a lot of points on this mesh if you really need a point cloud as output)
- use the contour/enveloppe extraction algorithm built in the 'Cross section' tool