Hello fellow DIYers,
I have been using the 3DR x8 coupled with a GoPro 4 Black and Pix4D to do topographic surveys for over a year now. While I have had great success with this platform, I have been having one issue that I just can't seem to find an answer for. I was hoping that someone out there might be able to help.
I believe that this is a fantastic platform for aerial surveys. It is common to see resolution of 2cm/pixel while using ground control targets. I will be upgrading the camera to a Sony a600 in the near future and hope to be running an Aerial RTK system soon. I have had no problem with the X8 or the PIX4D software, my problem is with the massive point cloud that you get after processing. I'm sure some of you have dealt with your computer crashing while loading these point clouds into AutoCad. And while having all those data points are nice, sometimes we only need a small amount to do the job efficiently. So, my question, do any of you know of a companion program to do planimetric mapping before uploading the point cloud to AutoCad? I would like to be able to extract the linework and upload only that file to AutoCad. Many thanks in advance!
Respectfully
Scott Eveld
Replies
First of all, you have to decimate the point cloud. More info you can find here
Thank you very much! I will try both to see which works best for our data set.
You can't beat Global Mapper. It only needs a few more functions to be just about complete. If you really want to deal with the point clouds in Autcad, you might try Carlson Software at carlsonsw.com. They have a point cloud module that is gaining some ground.
Hi Scott,
I use Global Mapper. It's a relatively cheap GIS/Mapping software package that comes with numerous tools for point clouds. The most effective for slimming down the point cloud are classification and DTM gridding. The software is about $400 and you'll need the LiDAR module for about $250. You can then export into CAD.
Hi Scott, could you explain what a planimetric mapping tool would do? I'm familiar with GIS but less with CAD. From a GIS perspective I would use this toolset: http://www.cs.unc.edu/~isenburg/lastools/
In looking through the options, there are a few ways to skin the cat, but two that come to my mind are thinning the points so you are only dealing with a percentage of them, or using polygons to clip out the areas you specifically want. I haven't used it, but one of the tools tiles a point cloud, which I assume breaks it into manageable chunks which can be brought into the CAD seperately. Good luck.