create a polyline from extents of points

[aluko0719]

is there a command to automatically draw a polyline around the outer limits of points. usually i manually draw a polyline around the points and then add that polyline to the surface as a outer boundary, but i have a huge survey.

[bryan]

If you have created a surface from your points you can use the SurfaceExtractObjects command to create a 3D poly from the boundary.

[vonfife]

Did you ever find a solution to this? I am having the same issue

[vonfife]

This doesn't work so well when their interior parts to the border.

[aluko0719]

I have not

Sent from my iPhone

[vonfife]

Thanks for the reply, it's not a big deal for my current project but would be nice if the method existed.

[Neilw_05]

Does aecshrinkwrap work with COGO points? I don't remember. If not, maybe explode the points down to generic Autocad objects and try the aecshrinkwrap command on those.

[BrianHailey]

I think the command is LINEWORKSHRINKWRAP (at least that's the only "shrinkwrap" type command I could find) and it doesn't seem to work on points.

As far as Civil 3D creating a polyline at the extents of the points, what's the extent?

In the following example, which polyline should Civil 3D use as the extents of the points?

Or something else all together?

Currently, Civil 3D doesn't do any of these automatically (I drew those all by hand) but, if you add the points to a surface, there are options available that will help you get a boundary that might be close to what you want.

[antoniovinci]

Not tried by myself, but this sounds good, gentlemen...

[Pointdump]

I hate to barge in and ask a stupid question, but since creating a Surface automatically creates an outer boundary, why do you want another boundary?

As @BrianHailey said:
"...if you add the points to a surface, there are options available that will help you get a boundary that might be close to what you want."

Choosing different Maximum Triangle Lengths removes "spiderwebbing" and tightens up the outer boundary.

Dave

[vonfife]

Tightening down the max triangle lengths like Pointdump and others pointed out worked good. Tried the shrinkwrap command out quickly on a point cloud but didnt have much luck. Thanks all for the input!

[Neilw_05]

Lineworkshrinkwrap is the command. I think it was renamed sometime in the distant past. Too, as you noted, it does not work on points of any kind. Obviously I haven't used it. I just knew it was there. As a workaround I tried using a block consisting of a triangle as points and exploding them down to plain lines. The shrinkwrap command just creates polylines around each of the triangles instead of enveloping the entire cloud. So the shrinkwrap tool really isn't much use for this scenario, though I think it was originally created for this purpose.

So as Brian suggested, the best solution is to adjust the triangle parameters in the surface properties to get it close. Then extract the boundary and refine it from there. Or look into a custom tool per Antonio.