Longitudinal section with broken intersection line

Question

Hello together! 
 In my projects I have to do with laser scanning in tunnels. From the measured point clouds I have to create horizontal ground views as well as vertical longitudinal sections and cross sections. I can generate the ground views and cross sections very easily by creating sections within the toolbox "Point cloud extended" - "Sections". This also works with longitudinal sections as long as the section line is a straight line, because then it is only a parallel projection of the point cloud in the XZ- or YZ-plane. 
 But now my question: for the creation of a longitudinal section along a broken intersection line I actually need to wind off the point cloud along this broken path. A simple parallel projection is not sufficient, otherwise the longitudinal section will be shortened. Is there a workflow for this? An additional problem is that the tunnel profiles are very irregular, as they are historical mining. This means that there is no horizontal ceiling and floor or no vertical walls. 
 I am looking forward to any hints! Thank you very much.

vincent · Accepted Answer

Hi, 
 There are no way now to project the actual point cloud, but you can pretty quickly get a line that will represent the point cloud intersection for your alignment. 
 For profiles, you can use the "Snap to element" tool from point cloud dialog to generate a 3D line that matches the desired (top of bottom) elevation of point cloud. Then projecting this line to profile, you shall get a pretty good approximation of the top and bottom of your point cloud. when using snap to element, play with circle tolerance depending on point cloud density,... 
 
 on the print screen, red line in profile is projected profile with top point cloud level, 
 On the left I overlaid the point cloud (white) with the projection of the line, you can adjust results with Snap parameters. 
 Workflow: 
 
 Create horizontal alignment with civil geometry 
 Create Profile at elevation higher than highest point cloud point 
 from 3D model,select the 3D alignment, and then from point cloud dialog take edit > Snap element Adjust settings, add vertices to create more computations steps 
 you get a new 3D element, 
 Take project profile to element, to project the 3D element onto your alignment.

Longitudinal section with broken intersection line

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