Mid-ordinate Distance?

[vsheehan]

We recently updated to Civil 3D 2009. When adding Feature Lines to a surface, I usually set the Mid-ordinate Distance to 0.1 to generate smooth contours. In C3D 2008, this work great but not so great in C3D 2009. I’ve also adjusted the Distance in the Supplementing factors along with the Mid-ordinate Distance. Is there another setting I need to adjust to generate smooth contours without adding elevation points along the Feature Lines? I’ve attached tow photos showing the settings and results.

Thanks!
Vince

[jpaulsen]

I just tried this in 2009 and it works as expected. If I set the mid ordinate distance to 1.0 the horizontal distance between the mid point of the surface line and the feature line is 1.0; if I set it to 0.1 it's 0.1

What is the actual horizontal distance from the mid point of surface line to the featyre line in your drawing? By the looks of the contours it's greater than 0.1'.

I recommend trying this in a new drawing using a different template. I used the acad.dwt (oops) for my test.

[vsheehan]

I tried using a new drawing with the Standard style. I'm still getting the same result. It actually works the first time I add Feature Lines or 3D Polylines to the surface and gets choppy when I add additional Feature Lines or 3D Polylines or update the surface.

[jpaulsen]

I added breaklines several times to an existing surface and every time it used the mid-ordinate value I typed in.

You probably know this already, but every time you add breaklines to the surface the weeding and supplementing factors go back to their default values. You have to set them every time.

[awhaley]

All the descriptions here, get you closer to what you need, here is another tool that you can use to generate smoother contours. If you go into the Surface style dialog, and click on the contours tab. (See picture) There is a slide that allows you to increase or decrease contour smoothing. I have had issues in the past with mid-ordinate distance being small (.5 or smaller), but with a distance of 1.0 and the style set to increased contour smoothing, it works pretty well. This is a feature in 2009 and 2008.

[brian.hailey933139]

In the name of the Allmighty Civil Engineer, I cast thee out, vile smooth contours! Begon back to the dark reaches of hell whence thou camest and touch not another C3D drawing henceforth!

Can you tell I'm not a big fan of smooth contours?

[jpaulsen]

Update.

Civil 3D 2010 allows you to set the default weeding and supplementing values in the settings.

[awhaley]

In the name of the Allmighty Civil Engineer, I cast thee out, vile smooth contours! Begon back to the dark reaches of hell whence thou camest and touch not another C3D drawing henceforth!

Can you tell I'm not a big fan of smooth contours?

I am impartial to smooth or sharp contours, but myproject manager wants them, so I oblidge. It does work prettywell though, especially in the context of this thread.

[brian.hailey933139]

I just had a tech support call yesterday, "Why won't my proposed contours tie into my existing? I did it exactly the way you said and they should tie in perfectly!" I turned the smoothing off on the existing ground and what do you know? They did tie in perfectly.

[awhaley]

Thanks for the info on that one. I have never had that issue, but when it happens, I will know the answer.