This is a continuation of an earlier post wherein I described problems with converting a large LIDAR dataset to DTM in Power Civil. I have the points file clipped to the area of interest and have sucessfully built a DTM. Now I want to thin the data to improve performance. The clipped data file contains almost 5 million points and is about 166 MB in size. When I run the Filter XYZ tool in LIDAR tools I get a memory allocation error. I have tried both the TILE and TIN filter options and have used the recommended settings in the help system.
I have 2 GB of memory on my Dual Core 1.6 GHZ XEON machine. Any suggestions on alternatives or troubleshooting techniques?
Power Civil XM ver. 08.09.06.30
Neil Wilson (aka Neilw)
Power Civil v8i 08.11.07.245
AutoCAD Civil 3D 2018
Neil - 2.5 million points is a fairly huge DTM. Not sure who advised you that you should be able to do 30 million. WIll PowerCivil do 30 milliion? Maybe, but probably not on a 2GB machine. Don't forget that your operating system and other processes will take a huge chunk out of the available memory. Looking right now at my computer, I have eaten up over 3/4GB and I haven't even opened PowerCivil yet.
Your memory allocation errors are telling you what the problem is. Your machine is, quite simply, choking on the huge amount of data in the TIN processing. This is why we built the LIDAR tools in the first place. LIDAR tools are so huge that they tend to choke everybodies computer.
I would advise trying a little more agressive settings in the thinning and compare the results to insure that you don't go too far.
Robert GarrettSenior Product EngineerBentley Systems Inc.
I did thin the data as far as I dared to. Z filter was 1.0 which gave marginal results. Actually Power Civil is handling it pretty well considering the size. The 30 million points info came from various inside sources. Not to say that is an official claim, but I believe it is in a blog or forum somewhere as well.
I managed to get the data into my other applications by using the same thinned XYZ file so the XML export is no longer necessary at this time.
It looks like we are going to need to move to a 64 bit OS soon with data like this becoming more and more common.
Good Morning Neil
The 30 million number apprently comes from our help file. (Thanks Mike). My experience still indicates that your computer is choking on the size of the data. But I am investigating. I have a LIDAR test set, but if you can send me a link to your your LIDAR file then I will look at yours. Or post it at ftp://ftp.bentley.com/pub/incoming and send me an email when it arrives.