AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Active Member
cman24
Posts: 10
Registered: ‎01-25-2013
Message 1 of 6 (447 Views)

Datum Surface not Consistent

447 Views, 5 Replies
01-29-2013 06:13 AM

Anyone know why a Datum Surface will correctly follow the bottom links of a corridor at 1 location but not another?

 

Please see attached.  The 2 stations shown use the same assembly and are in the same region. Some locations appear to be correct, while a few other locations "skip" points they are supposed to hit.

*Expert Elite*
jmayo
Posts: 3,001
Registered: ‎11-13-2006
Message 2 of 6 (428 Views)

Re: Datum Surface not Consistent

01-29-2013 08:19 AM in reply to: cman24

Did you toggle the overhang correction to 'bottom links'?

John Mayo, PE
IDSP 2014
Win 7 64, Xeon ES165@3.2Ghz,
64 GB RAM, Quadro K4000 (x2)
Active Member
cman24
Posts: 10
Registered: ‎01-25-2013
Message 3 of 6 (425 Views)

Re: Datum Surface not Consistent

01-29-2013 08:22 AM in reply to: cman24

Yep. 

 

I am hoping I am just missing something simple like that, but I just can't figure out what it is.  It wouldn't be so frustrating if the error occured at every location, but the fact that it works at some and not others is just confusing.

Valued Mentor
david.zavislan
Posts: 279
Registered: ‎10-31-2006
Message 4 of 6 (393 Views)

Re: Datum Surface not Consistent

01-30-2013 07:46 AM in reply to: cman24

If you look at the surface triangulation in plan view you will probably see that the tin lines are not created correctly along the vertical portion of the datum.   Two ways to fix this:

 

1. Reduce the frequency distance.  This will output more link data to the surface, which should cause the triangles to form correctly between the adjacent corridor sections.

 

2. Or, add feature lines from the top and toe point codes.

AddCorridorFeaturelinesToSurface.jpg

David Zavislan, P.E. | Wood Rodgers, Inc.
Employee
peterfunkautodesk
Posts: 720
Registered: ‎08-25-2009
Message 5 of 6 (384 Views)

Re: Datum Surface not Consistent

01-30-2013 08:46 AM in reply to: david.zavislan

What subassembly was used to create the curb? It looks like you have three points at the same place vertically and this is causing the TIN "issues". We've tried to make our internal subassemblies have a very slight offset (moving to away from the centerline) to avoid these conditions.

 

Regards,

 

Peter Funk

Autodesk, Inc.



Peter Funk
Autodesk, Inc.

Active Member
cman24
Posts: 10
Registered: ‎01-25-2013
Message 6 of 6 (372 Views)

Re: Datum Surface not Consistent

01-30-2013 02:33 PM in reply to: cman24

This is a subassembly from our Client (WisDOT).  I've experienced issues before related to the vertical stacking of points.  There is a slight offset with this subassembly, but maybe it's not enough of an offset.  I just found it odd that it worked in some locations and not others.  I think I will just have to apply a work-around like what David suggested until I can get an update to this subassembly.

 

Thanks for the help.

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