AutoCAD Civil 3D General

Posts: 222
Registered: ‎12-19-2006
Message 11 of 14 (101 Views)

Re: Crossing breaklines

09-05-2013 09:23 AM in reply to: gk

you can use the add line functionality without deleting the lines already there. It works like a mass swap edge command. It treats the line yuo want added as if it were a breakline and then swaps all the necessary edges to conform. this will avoid the "black holes" that occur when deleting interior tin lines.

Valued Mentor
Posts: 1,086
Registered: ‎01-07-2011
Message 12 of 14 (98 Views)

Re: Crossing breaklines

09-05-2013 09:31 AM in reply to: gk

From now on I will 'Add Lines' only...


Whoa, step back!  Too extreme....this is kind of subtle now....


That's not what she's saying. She suggests deleting surface points rather than deleting surface lines. Deleting surface lines creates holes.


Deleting surface points causes re-triangulation and does not create holes. 


I like the one person's suggestion of placing a surface point just to get triangulation going over the hole, and the deleting the surface point.





Fred Ernst, PE
C3D 2015
Ernst Engineering
Valued Mentor
Posts: 1,086
Registered: ‎01-07-2011
Message 13 of 14 (94 Views)

Re: Crossing breaklines

09-05-2013 09:44 AM in reply to: jmayo

"you may want to limit the surface definition to the points and contours only."


This approach typically does not allow the new surface to sucessfully emulate the V-shape of the contours in drainages, nor the depict the correct longitudinal slopes of the drainages provided by the breaklines.


Perhaps try adding the points and breakilnes first, then add the contours as breakilnes. Then choose to Allow Crossing Breaklines with the option Last selected.

Fred Ernst, PE
C3D 2015
Ernst Engineering
*Expert Elite*
Posts: 2,696
Registered: ‎11-13-2006
Message 14 of 14 (82 Views)

Re: Crossing breaklines

09-05-2013 11:24 AM in reply to: fcernst

Hey Fred. With field shot data things are different because the data is much more accurate. In these cases I agree the build order and I would never exclude breaklines. When dealing with aerial topo pavement breaklines rarely match contour elevation in my experience (I think that is the issue in this post) and rarely do I see a well defined crown in these contours. We also have bld outlines at roof elevation and other things to deal with like the fact that it will never match the original perfectly and it's most likely not accurate enough to build with (at least in our area). In that case, for my purposes, I want my new contours to be smack on with the source. My map will match their map. I don't want anyone asking why contours are different. So with the points and contour only method I get a great match in less than 5 min almost every time. The last thing I want my staff to do is spend 1/2 a day fixing work that was already completed by others.

John Mayo, PE
IDSP 2014
Win 7 64, Xeon ES165@3.2Ghz,
64 GB RAM, Quadro K4000 (x2)

You are not logged in.

Log into access your profile, ask and answer questions, share ideas and more. Haven't signed up yet? Register

Are you familiar with the Autodesk Expert Elites? The Expert Elite program is made up of customers that help other customers by sharing knowledge and exemplifying an engaging style of collaboration. To learn more, please visit our Expert Elite website.

Need installation help?

Start with some of our most frequented solutions to get help installing your software.

Ask the Community

Civil 3D Exchange Apps

Created by the community for the community, Autodesk Exchange Apps for AutoCAD Civil 3D helps you achieve greater speed, accuracy, and automation from concept to manufacturing.

Connect with Civil 3D