topic Large Point Cloud Surface Creation in Civil 3D Forum

Large Point Cloud Surface Creation

Anonymous — Mon, 02 Nov 2015 14:24:59 GMT

I have a massive point cloud created from a drone on a large piece of land, about 100,000,000 points. I ran the LAS files through Recap to make an RCP file. I attach the point cloud and try to process a surface from it, after about an hour it crashes. Is there a way to process a surface from this large point cloud that will work?

Re: Large Point Cloud Surface Creation

Pointdump — Mon, 02 Nov 2015 16:27:11 GMT

Mr. B,

With 100,000,000 points, I'm surprised it took a whole hour to crash. My laptop would have cratered in seconds. Is there any way you can break up the point file?

Dave

Re: Large Point Cloud Surface Creation

Anonymous — Mon, 02 Nov 2015 16:41:51 GMT

Hi David,

I have 48 smaller scans Which is alot of surfaces. Is there a max number of points for an efficient surface to be created? If I break it up in recap into say 4 smaller projects of 40,000,000 points and merge the surfaces will this work? do you have any ideas? also the point cloud surface extraction toll, do you know if this is a seperate add-on, or is it included in a service pack?

Re: Large Point Cloud Surface Creation

Pointdump — Mon, 02 Nov 2015 16:57:43 GMT

Mr. B,

Worst case scenario, you can make 48 drawings, Simplify the Surfaces, and then put 'em together:

http://help.autodesk.com/view/CIV3D/2016/ENU/?guid=GUID-81482A2A-B158-4A2F-88C6-97676CF1AA05

Disclaimer: I've never worked with Point Clouds.

Dave

Re: Large Point Cloud Surface Creation

rl_jackson — Mon, 02 Nov 2015 17:00:23 GMT

You may need to see about reducing the density of the scan, Is this a scan of vacant land, ditches roads etc.. (topo) or something else.

Re: Large Point Cloud Surface Creation

Neilw_05 — Mon, 02 Nov 2015 17:32:53 GMT

I think you'll have problems with any surface that exceeds a couple of million points. You'll have to do a lot of filtering to get your data into a surface. Work for a target of maybe 2 million points per surface.

Re: Large Point Cloud Surface Creation

dblackRQCP8 — Mon, 02 Nov 2015 17:33:46 GMT

Yes, it is vacant land. It's a survey of a river. i have cut out some of the irrelevant survey. I seen a point cloud surface extraction tool for 2015, Is this available for 2016 or already built into it?

Re: Large Point Cloud Surface Creation

Neilw_05 — Mon, 02 Nov 2015 17:41:14 GMT

P.S...before you get too far into the processing, run some tests on a surface to see how it performs. 2 million points may or not be manageable.

Re: Large Point Cloud Surface Creation

dblackRQCP8 — Mon, 02 Nov 2015 17:56:18 GMT

Thanks Neil. I increased the point spacing to 1 and it came in fine. It looks pretty good, Thanks for all the help everyone.

Re: Large Point Cloud Surface Creation

autoMick — Tue, 03 Nov 2015 06:44:41 GMT

Civil3d can only display and utilise 10 million points at any one time at a maximum (and the practical limit is often less). So 90% of your data was going to be redundant anyway.There's two ways I can think of dealing with it

1 - when importing the data to recap using a higher decimation setting, to reduce data density; or

2 - create lots of small surfaces in Civil3d, simplify them, then paste them together.

The other thing is that if there's a lot of water, then look at the LAS classification and filter out all the non-ground return data

Cheers

- Mick