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.
Please see attached pictures...
Thanks for any help that can be provided...
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 -
Alfred, thanks for your prompt reply!
Basically that's exactly what I would like, without having to create the surface. Possibly a .lsp routine or something to that effect...
Out of curiosity why don't you want to create a surface? Is it extremely large?
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.
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.
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...
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.
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
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
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