Surfaces from LARGE xyz files

[Anonymous]

Is there a way to create s surface from an xyz format file without having to import the points into a drawing file?
My point file is 78MEG from LiDAR output.

[apweng]

Yes,

You can create a surface from points that reside in an external text file. One of the surface data options is Point File. You can set up a point file format that reduces the number of points originating in the LiDAR file (ie sample every nth point).

Andrew

[Anonymous]

gregmoore wrote:
> Is there a way to create s surface from an xyz format file without
> having to import the points into a drawing file? My point file is
> 78MEG from LiDAR output.

As Andrew said, yes, you can add an external point file as surface data.

However, to keep your head from exploding along with your computer, have
you considered weeding those points just a bit? I haven't tried a
point file like that before, but wow - a text file that large? That's
gotta be a lot of points.

--
Jason Hickey
www.civil3d.com

[apweng]

Jason that's what I was referring to with the point file format. Data sets this size are typical of LiDAR. The density of the points is usually far greater than what you need (can vary significantly between planning and detailed design).

Years (decade?) ago I wrote a simple routine to filter through XYZ points (to take every nth point) that were a by-product of the aerial photogrammetry process. In C3D you can do this in the point file format manager.

Andrew

[Anonymous]

Jason,

You are correct in that it is a lot of data in LiDAR files. It's quite a
bit of information indeed, and probably more than is needed. The relief
maps generated from them are quite impressive.


Bryant Quinney
ISD Applications Engineer
Construction Industry Solutions (COINS)
Irving, TX

C3D 2007, SP1A
Pentium M/2.26GHz
2GB RAM
XP Pro, SP2
nVidia Quadro FX Go1400, 256MB

Jason Hickey wrote:
> gregmoore wrote:
>> Is there a way to create s surface from an xyz format file without
>> having to import the points into a drawing file? My point file is
>> 78MEG from LiDAR output.
>
> As Andrew said, yes, you can add an external point file as surface data.
>
> However, to keep your head from exploding along with your computer, have
> you considered weeding those points just a bit? I haven't tried a
> point file like that before, but wow - a text file that large? That's
> gotta be a lot of points.
>
> --
> Jason Hickey
> www.civil3d.com

[Anonymous]

apweng wrote:

> Years (decade?) ago I wrote a simple routine to filter through XYZ
> points (to take every nth point) that were a by-product of the aerial
> photogrammetry process. In C3D you can do this in the point file
> format manager.

You know, I never knew that. To be quite honest, I doubted you until I
went and looked for myself. Thanks for pointing that out - I can
definitely use that one.

--
Jason Hickey

Civil 3D 2007, SP1A
Dell Precision M70
2 GIG RAM, 256 MB nVidia Quadro FX Go1400
Intel Centrino 2 gHz Processor

www.civil3d.com

[apweng]

All in the best interestes of data managment Jason!

Andrew

[Anonymous]

I seem to remember a 10MB DEM XYZ point file turning into an 80MB surface in
Civil3D.........scary to think of 80MB point file.

"Jason Hickey" wrote in message
news:5309933@discussion.autodesk.com...
gregmoore wrote:
> Is there a way to create s surface from an xyz format file without
> having to import the points into a drawing file? My point file is
> 78MEG from LiDAR output.

As Andrew said, yes, you can add an external point file as surface data.

However, to keep your head from exploding along with your computer, have
you considered weeding those points just a bit? I haven't tried a
point file like that before, but wow - a text file that large? That's
gotta be a lot of points.

--
Jason Hickey
www.civil3d.com

[Anonymous]

Andrew,
Thanks for the info but it appears that this methoid still imports the points to the dwg. In settings I created a file format that samples every nth point. Then the only option I can find is to Import the points using this format. In the Edit Command Settings, I can further limit the size by restricting the elevations, max length ect, but I want to avoid placing these points into the dwg.

[apweng]

Don't import the points first. Expand the data tree after you create a surface and select point files from there.

The same mechanism used to import points is used to select points from an external point file for surface modeling.

Andrew

[Anonymous]

Andrew,
I create a surface in Prospector, expand the data tree in prospector to show the Definition- Point Files. I click to add a point file. There are no options to pick a file format. I pick on an
xyz formatted file and get the error " Invalid format specified.
Expected file format Point Number x y z. These files have no Point Numbers. Am I in the wrong menu tree?

[apweng]

Greg well that's strange then. When I right click on the Point Files tree and select Add... the Add Point File dialog box appears - where you can select a format and the source file.

Andrew

[Anonymous]

Andrew,
Thanks for your help. I expected to see a menu pop up that is like the points format in the settings tab but I get the Import point file menu. I have attached a screen capture of what I am getting. Are there config issues? Patch Issues? I have sp2 loaded. I am dead in the water on this.

[nzeeben]

If I had to guess greg is using 2006. Where as andrew has 2007.


wrote in message news:5311040@discussion.autodesk.com...
Greg well that's strange then. When I right click on the Point Files tree
and select Add... the Add Point File dialog box appears - where you can
select a format and the source file.

Andrew

[Anonymous]

Yes I am using 2006

[apweng]

Thanks Nick - I didn't realize that functionality was not there in 2006.

Well if that's the case then I think you'll be hard pressed to work with that much point data in C3D.

The functionality is for sure in Land Desktop which you probably have.

Andrew

[nzeeben]

You can use points->utilities->transfer to convert your current point file
into the approriate format. 2006 requires PENZ . 2007 allows you to
select your own format.
Nick
wrote in message news:5311075@discussion.autodesk.com...
If I had to guess greg is using 2006. Where as andrew has 2007.


wrote in message news:5311040@discussion.autodesk.com...
Greg well that's strange then. When I right click on the Point Files tree
and select Add... the Add Point File dialog box appears - where you can
select a format and the source file.

Andrew

[Anonymous]

Nick, Andrew,
Thanks again. I will try the data transfer route again but I think the last time I tried this My computer choked. FATAL ERROR out of memory. I will also try LDD 2006.
Thanks,
Greg

[Anonymous]

Andrew & Nick,
I have concord the LiDar data files, at least the small ones,78 meg. Here is how I did it. First open LDD 2006,
import the xyz file using a modified xyz format to sample every fourth point. You have to import the points into LDD because this is the only way to assign a point number to each point. Transfer data will not. OK then export the point file from LDD using the PENZ space format, this is what CD3 is looking for. Then in C3D 2006 use the point file in Surface data tree to use these points. Careful not to have the surface style show points, only border. Iwas able to use 526,000 points and then manipulate the model using the surface createsurface comand. Just thought I would pass this info Forward. Thanks again for all your help.
Greg

[nzeeben]

Glad to hear it Greg,

It is possible to work through the larger datasets alot of the time, I have
had a few in the 200,000 point range.

Nick
wrote in message news:5311552@discussion.autodesk.com...
Andrew & Nick,
I have concord the LiDar data files, at least the small ones,78 meg. Here is
how I did it. First open LDD 2006,
import the xyz file using a modified xyz format to sample every fourth
point. You have to import the points into LDD because this is the only way
to assign a point number to each point. Transfer data will not. OK then
export the point file from LDD using the PENZ space format, this is what CD3
is looking for. Then in C3D 2006 use the point file in Surface data tree to
use these points. Careful not to have the surface style show points, only
border. Iwas able to use 526,000 points and then manipulate the model using
the surface createsurface comand. Just thought I would pass this info
Forward. Thanks again for all your help.
Greg