Point Clouds

Its_Alive

Anyone here do point clouds or use LIDAR?

Richard Webb

Peripherally. I recently did the post-processing data extraction, sanity checking, and preliminary visualization for some 3D sonar data (theta, phi, rho) out of some XTF (Triton) formatted files. This was a one-off so I just used my ancient copy of Mathcad for the coordinate conversion and 3D plotting. I'd probably run it up in Scilab if became a regular thing, though.

Its_Alive

Thanks for the reply!
I've created a little routine to import an LIDAR .las files into a custom point cloud entity. At this point (no pun intended)  it's not really that useful except for viewing and doing Delaunay triangles. I was thinking about adding surface reconstruction using cgal.

see
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Surface_reconstruction_points_3/Chapter_main.html

I posted it at theSwamp
http://www.theswamp.org/index.php?topic=34607.0

Jerry Johnson

I use a reflectorless instrument which I have occasionally used to do structure "Portraits". Shooting the floor levels, opening, etc. Because you will often end up with different Z's at the same X,Y location -- I bring them in separately, rotate around X axis to put Z values as Y, then surface. But with digital photos I think I'll use another method next time out. Just for your info.Jerry

Richard Webb

Interesting link, Daniel. Thanks! The 3D sonar imaging isn't my usual area of operations, so I'm not really up to date on the state of the art. Might be fun to go back over some of the data with the Cgal tools.