Discussion Groups

Active Member
Posts: 8
Registered: ‎10-28-2011

# Help, need to create a boundary around a mass of scattered points...

575 Views, 17 Replies
10-28-2011 11:14 AM

CIVIL3D 2012

I'm trying to create a boundary (either 2D or 3D polyline) around a group of random scattered cogo points.

The boundary or polyline vertices needs to be "attached" to, or at least sharing the same x,y,z coordinates as the points that create the perimeter of the group of scattered points.

The reason for this is to eliminate the lengthly tedeous process of creating a polyline and having to snap each consecutive vertice to the next point on the perimeter of a mass group of points (like 1000's of points).

I have looked into using the "Shrinkwrap" command, but it's not doing what I need.  It only seems to duplicate an existing polyline that surrounds the group of points, failing to attached to the points on the perimeter.

Thanks for any help that can be provided...

John

*Expert Elite*
Posts: 6,460
Registered: ‎06-29-2007

# Re: Help, need to create a boundary around a mass of scattered points...

10-28-2011 11:21 AM in reply to: coburnj

Hi,

if you create a suface based on these points, set the style to show the border, then extract the border of the surface ==> will result in a polyline (would be a 2min way).

If that's what you look for, ok; if not ... what is the rule to make it better? With "rule" I mean what would be your strategy to get a (for you) better result?

- alfred -

-------------------------------------------------------------------------
Ingenieur Studio HOLLAUS ... www.hollaus.at
-------------------------------------------------------------------------
Active Member
Posts: 8
Registered: ‎10-28-2011

# Re: Help, need to create a boundary around a mass of scattered points...

Basically that's exactly what I would like, without having to create the surface.  Possibly a .lsp routine or something to that effect...

Regards,

John

Active Contributor
Posts: 46
Registered: ‎06-04-2010

# Re: Help, need to create a boundary around a mass of scattered points...

10-28-2011 11:30 AM in reply to: coburnj

Out of curiosity why don't you want to create a surface?  Is it extremely large?

Michael D Smith
Autodesk Application Specialist
Cansel - Autodesk Division

"Improving field to finish productivity"
www.cansel.ca

Increase your productivity with one of our Upcoming Training Events…
Active Member
Posts: 8
Registered: ‎10-28-2011

# Re: Help, need to create a boundary around a mass of scattered points...

10-28-2011 11:34 AM in reply to: mikesmi

I'm looking for the most efficient route possible.  I realize that creating a surface, extracting the boundary and then editing it to fit to my preference is significantly more efficient than tracing the outline perimeter of a mass group of points.  But, I'm reallly just looking to invoke a command that will allow me to select a group of points and have a perimeter boundary created.

*Expert Elite*
Posts: 2,696
Registered: ‎08-01-2008

# Re: Help, need to create a boundary around a mass of scattered points...

10-28-2011 11:57 AM in reply to: coburnj

If you are determined not to use the surface method then the easiest manual method is probably to set OSMODE to Node and OSNAPOVERRIDE to 1, this will only let you select the nodes but it could be a bit tedious.

Another way of approaching the surface method is to create the surface and then add a destructive boundary to delete spurious triangles.

neilyj
(No connection with Autodesk other than using the products in the real world)

IDSP Premium 2014 (mainly Civil 3D 2014 but also 3ds Max Design)
Win 7 Pro x64, 256Gb SSD, 300Gb 15,000 rpm HDD
16Gb Ram Intel Xeon CPU E5-1607 0 @ 3.00GHz (4 CPUs), ~3.0GHz
NVIDIA Quadro 4000, Dual 27" Monitor, Dell T3600
*Expert Elite*
Posts: 2,271
Registered: ‎07-09-2003

# Re: Help, need to create a boundary around a mass of scattered points...

10-28-2011 12:47 PM in reply to: coburnj
Basically there is no built in wlmethod to do what you need. So either you pay someone to create a tool for you (or someone here offers one for free) or you go to the next most efficient method...surface creation. Delete the surface after. Creating that surface is seconds worth of work.
Matt Kolberg
Cansel - Autodesk Division
http://www.cansel.ca/
Active Member
Posts: 8
Registered: ‎10-28-2011

# Re: Help, need to create a boundary around a mass of scattered points...

10-28-2011 12:57 PM in reply to: mathewk

its the editing of the boundary that i'm trying to avoid...the surface boundary works, but there is still plenty editing to do...I agree, it's better than the long manual way...but I need more efficiency...

Thanks to all who have responded, it's much appreciated...

Regards,

John

Valued Mentor
Posts: 389
Registered: ‎06-06-2010

# Re: Help, need to create a boundary around a mass of scattered points...

10-28-2011 01:01 PM in reply to: coburnj

If you were to consider third party software, we've just added Shrinkwrap Points to the MapWorks Points module.  Simply select the Civil3D points and it instantly generates a 3dPoly.

Active Contributor
Posts: 46
Registered: ‎06-04-2010

# Re: Help, need to create a boundary around a mass of scattered points...

10-28-2011 01:02 PM in reply to: coburnj

Do you use the surface "delete line" command in conjuction with the CP (crossing poly window)  makes for very easy boundary editing.  See example pic where I are editing the boudary in one shot.  No selecting points just removing lines

procedure:

select surface

select edit surface

select delete line

type cp at the command line press enter

create funky shape around surface

enter to delete all lines touched

Michael D Smith
Autodesk Application Specialist
Cansel - Autodesk Division

"Improving field to finish productivity"
www.cansel.ca

Increase your productivity with one of our Upcoming Training Events…