Anyone using a program that automatically (more or less) will produce breaklines in a point cloud?
My issue is this: When using LIDAR returns to produce a topo map for a particular parcel I will end up with sometimes upwards of 100k points with the individual points being no more than a foot or less apart. I can create contours from these that represent the ground well but they are very jagged and un-smooth do to the gajillions of tin lines.
One method I have used to reduce this effect is to create a grid from the returns (I use Terramodel 10.3). I will use anywhere from a 10 to 25 foot grid spacing, though anything over 15 foot tends to lose roads.
My feeling is that what is missing here are the break lines that I would normally create to control the Tin and hence the smoothness of the contours. creating them from the returns manually would be possible by inspecting the elevation, but would be very tedious and time consuming. It seems like something a program could easily handle, but I have not found any that are not part of larger, and way too expensive, pointcloud programs.
Any ideas?
Try your grid, plus use filtered and smoothed contours to create the tin.
I think I would want to use the wirefame to cull the surface significant points.
If you could turn your wireframe into a shaded solid you would easily be able to visually identify the anthills, tops of bushes..
If the software you're using allows you to display point nodes, you could create a list of points by selecting them with the mouse and removing these points from a COPY of the original point file.
Plot new point file, create new tin, and contour. From the point density and number of shots it sounds like two acres of area. You may just have too much data for a decent plot of contours.
