How to generate a deep topographic surface from combined xyz DTM point cloud and cutting planes?

Dear all, I have to generate the depth topography of a sliding mass. I have the point cloud (xyz data set) resulting from the actual topography and I know the orientation of the intersecting planes (4 planes) that define the deep rupture surface. How can I generate a single solid surface formed by the conjunction of the intersecting planes with the topography outside of the sliding source area?

Pascal Golay probably has the best answer. My answer is:
SrfPtGrid command draws a surface from a grid of points that lie on the surface.
CreateSolid command creates a closed polysurface from selected surfaces that bound regions in space. The surfaces must overlap and intersect.

Hi Alberto - can you post a file or send to It’s hard to picture without the file but I can imagine possibly several intersecting patch surfaces from subsets of the points might work.


Thank you Andrew for your valuable suggestion! I’ll try those commands.

Thank you Pascal for your response! I sent you the file at