Cross sections with vertices only on contour intersections

[Anonymous]

Hello everyone,

I just began using Civil 3D 2018 to create surfaces and contour maps. Now I need to create cross sections. I watched some videos on youtube and came up with the procedure I need to follow to create cross sections, but the way they are created does not suit my needs. I specifically need the cross sections vertices to be created only where the sample lines intersect the contours instead of following exactly the 3D surface. Much like when we do this by hand. I searched on Google, but didn't come up with an answer or something close.

Your help will be greatly appreciated!

[jmayo-EE]

That would skip any and all relative highs and lows between the contours....

You could try by defining a suface with nothing but contours...but this is a poor modeling method. Contour data is the least accurate elevation data on a map. +/- half the interval...

Also contours are a result of the elevation data, not the defining source.

This all seems related to old drafting methods and that leads directly to poor CAD/BIM modeling...

[Mike.M.Carlson]

Hi friend-

Civil 3D will not sample a surface that way unfortunately.  The only thing I could suggest is to try to create cogo points via the Create Points - Surface command that coincide with your cross section sample lines and contour increments and build a new surface based on those cogo points.  Then the Cross Section Views should show the surface representing the TIN connecting the COGO points along the sample line the way you want it.  It will require a little more work this way though.

I hope this helps.

[Anonymous]

Actually, I didn't explain correctly what I need. The contours I created have 0.5m interval. In the example shown below, you can see that the horizontal axis' tick marks are placed arbitrarily, whereas I want them to display the values of the intersections between the sample line and the contours, which in this case would be 16.85, 15.50, 16, 16.50 and so on.

[Mike.M.Carlson]

I understand...You would have to follow my approach above to create a new surface from cogo points created along the sample lines at the intersection of each contour increment.  Then you will have to edit your Section View Data Band Details to place labels at "Grade Breaks" (please see below).

  

I hope this helps.

[Anonymous]

But as @jmayo-EE said, if I create x-sections with COGO points, everything between the points will be omitted. I tried setting the grade breaks to Full Band Height Kicks, but nothing changed unfortunately.

[Mike.M.Carlson]

Yes @Anonymous is totally correct.  You could display the full sampled surface, which will have all the data in between the contour increments shown.  However, you will also need a 2nd surface that is based on the point method I described earlier, and have the Section Band point to this second surface, so the contour increments are labeled in the Band the way you want it.  Just assign this second surface a No Plot style, so it doesn't actually show in Section View, but is referenced for Band Labeling.

I hope this helps.

[Anonymous]

It helps, but I have to come up with almost 1000 x-sections in a limited amount of time and this would take a lot of time. I will keep searching and if nothing comes up I'll do it your way. Thank you anyway!

[Mike.M.Carlson]

Ouch!  Sorry to hear that.  Yeah my method is not quick.  Good luck.

[Jeew-m]

Dear Friend,

Select a section.

Go to section view properties.

Identify the band that relates to offset data.

1. Click on the icon on the band

2. Go to edit current style.

3. On the Band Details tab go to Grade Brakes.

4. Click on compose label

5. Make sure you have distance from center line is active in the text contents. Otherwise you need to create it.

6. On the display tab make sure you have turned on the layer for Labels at Grade Breaks.

7. For the surface make sure you have selected the existing ground.

However if you have tiny grade changes in the surface (since this is existing ground) you might get lot of data in the offset band.

Thank you.

[Joe-Bouza]

I’m trying to think this through.
If all the contours were perfectly perpendicular to my sample lines I be golden. But they’re no so I scale out along my sample line until I hit a contour and plot the elevation. I keep doing that until I get to the end of the sample line. Then I connect the dots... kind of like a Civil3d surface plot

[Joe-Bouza]

Pardon my synical post, but how do you justify connecting the dots?

[Joe-Bouza]

If the elevation between contour is no good then you may want to edit the surface