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Detention Pond Contours Not Correct

13 REPLIES 13
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Message 1 of 14
ToddRogers-WPM
1229 Views, 13 Replies

Detention Pond Contours Not Correct

I have 2 feature lines, one is at elevation 132 (TOB), and the other at 123 (TOE).  I inserted elevation points at an increment of every 3 ft., which should make a smooth arc of contours around the pond.  Not the case.  How do I fix the issue I am having?  See pic below...

 

4-4-2012 8-46-10 AM.png 



Todd Rogers
BIM Manager
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13 REPLIES 13
Message 2 of 14

Is your surface set to use a maximum triangle length?



Lisa Pohlmeyer
Civil 3D User
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Message 3 of 14
sboon
in reply to: ToddRogers-WPM

Switch your surface style to display the TIN lines.  The rules of Delauney triangulation generally force the surface to connect surface points to their nearest neighbours, so in this case you likely have lines running across the inside of your curves, instead of from the inside to the outside featureline.

Steve
Expert Elite Alumnus
Message 4 of 14
ToddRogers-WPM
in reply to: sboon

4-4-2012 8-46-10 AM.png



Todd Rogers
BIM Manager
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Message 5 of 14
jmayo-EE
in reply to: ToddRogers-WPM

The quick way to fix this is to add them to the surface definition as contours making sure to minimize the flat areas. If you add them as breaklines you will be flippin' all those edges.

John Mayo

EESignature

Message 6 of 14
jmayo-EE
in reply to: jmayo-EE

... you will have fewer triangles to flip and a better performing surface if you remove all those elev points.

John Mayo

EESignature

Message 7 of 14
ToddRogers-WPM
in reply to: jmayo-EE

It's not allowing me to add the feature lines as contours...



Todd Rogers
BIM Manager
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Message 8 of 14
jmayo-EE
in reply to: ToddRogers-WPM

Oh that's a bit of a bummer. I do use simple plines for basin & bld pad surfaces quite often. Not the greatest solution but if the basin was disconnected from the rest of the design it may not be a big deal losing the dynamic capabilities.

 

The other option is flipping the edges. In both cases I would remove the elv pnts.

John Mayo

EESignature

Message 9 of 14
jmayo-EE
in reply to: ToddRogers-WPM

A grading (I don't like these) or corridor are other options but it does not look like the top and bottom outer curves have the same radius as the offset. The lack of symmetry makes these options tough.

John Mayo

EESignature

Message 10 of 14
ToddRogers-WPM
in reply to: jmayo-EE

I did remove the elevation points.  I exploded the feature lines and added the poly's as contours.  MUCH more control this way.  I will have to remember this workaround.  Thanks for the info!!



Todd Rogers
BIM Manager
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Message 11 of 14
sboon
in reply to: ToddRogers-WPM

Another solution would be to add breaklines at the corners from the inside to the outside curve, similar to what the software does with grading objects.  This should force the surface to triangulate better.

 

Clipboard01.png

 

Steve
Expert Elite Alumnus
Message 12 of 14
ToddRogers-WPM
in reply to: sboon

Interesting.  I will try this as well.  Thanks Steve.



Todd Rogers
BIM Manager
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Message 13 of 14

make the boundary which is the TOB and BOB 3D polyline and then add them as contours and select the swaping edges and unselect the filling gaps in contour data....make the distance .1, angle .001.00000, distance 1 and mid-ordinate .5 and that should work perfect

Message 14 of 14

That worked like a charm!!



Todd Rogers
BIM Manager
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