AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Accepted Solution

LiDar Surface

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10-30-2013 01:41 PM

I was supplied with LiDar data in XYZ format.  I import the blocks via point clouds, each seperate block in a seperate point cloud.  The point cloud details show that the cloud contains about 2.5 million points.  When I create a surface from the point cloud it will only use 48 000 points from the 2.5 million.  I combined all my point clouds (27) to create a large surface, and it only contains 77 516 points.  By my calculations it should contain 2.5 million x 27 = 67.5 million.  Is there any way to have my surface contain all the points from the point cloud?

 

Thanks, 

Regardless, your Civil 3D surface will use no more than 1.5M points no matter how large your lidat survey. Big reason I don't use point clouds in C3D.

You're better off to use the Point Files option when making your surface.
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Re: LiDar Surface

10-30-2013 02:10 PM in reply to: awall

Try changing the Point Cloud density to a higher number.  I think by default it is only set to 15 out of 100.

If the issue was resolved by this method, please click on "Accept As Solution"
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Todd Rogers

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Re: LiDar Surface

10-30-2013 02:12 PM in reply to: awall
Regardless, your Civil 3D surface will use no more than 1.5M points no matter how large your lidat survey. Big reason I don't use point clouds in C3D.

You're better off to use the Point Files option when making your surface.
Matt Kolberg
Cansel - Autodesk Division
http://www.cansel.ca/
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Re: LiDar Surface

10-30-2013 02:21 PM in reply to: mathewk

I have had a very difficult time when importing the lidar data as point files.  Extremely slow and most times Civl 3D will sotp responding.  I open the task manager and it shows its only using 10% of the CPU and 10% of the Ram.

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Re: LiDar Surface

10-30-2013 02:21 PM in reply to: awall

Matt's right.  You are better off "attaching" the point file.

If the issue was resolved by this method, please click on "Accept As Solution"
*Civil 3DJ*
Todd Rogers

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Re: LiDar Surface

10-30-2013 02:22 PM in reply to: mathewk

In any event, using every single point of a 60M +/- point scan wouldn't produce much of a difference, except for a horrifically unmanageable file size.  For the most part, the intermediate points will lie on a the surfaces formed from the other points.  They may be a little higher or lower, but shouldn't be signficantly so.

 

Kind of like modeling every nuance of a thread and rounded bolt head on a screw for a 1:50 drawing.

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Re: LiDar Surface

10-30-2013 02:23 PM in reply to: TRogers

When I increased the point cloud density from the default 15% to 100%, it still only included the same 48 000 points when I would create a surface per point cloud.

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Re: LiDar Surface

10-30-2013 02:24 PM in reply to: awall

Probably more like 15%, where you are showing combined activity in a hex-core processor.  If you switched to individual core monitoring, you would see one of the cores pegged at or near 100%.

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Post 9 of 12

Re: LiDar Surface

10-30-2013 02:35 PM in reply to: awall
Awall, when I say poit fikes, I don't mean importing COGO points, just to be sure you're not attempting to import 2.5M points. This will fail every time.

I can attach 2.5M points to my surface in minutes with no trouble at all.
Matt Kolberg
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Post 10 of 12

Re: LiDar Surface

10-30-2013 03:09 PM in reply to: mathewk

Matt, it took me a little bit to figure out what you meant, but I understand.  Create a surface and just attach the point files instead of importing the points and creating point groups and attaching them.  It sounds like a much better method than what I had orginally attempted.  I will give it a shot and let you know how it works.  Thanks for the help!

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