Contour lines jagged, not smooth

Re: Contour lines jagged, not smooth

Rousenator — Fri, 02 Aug 2013 08:40:15 GMT

Hi everyone,

i use Geopak for my DTM construction and have found that the best way of achieving a 'smooth' DTM is by creating a LATTICE as opposed to a TIN. Its the best way of removing 'sharps' that are created by the contour data used, without having to smooth out the contour linestrings.

Re: Contour lines jagged, not smooth

neilw — Sat, 05 Sep 2009 03:29:56 GMT

Typically the jagged contour behavior occurs when there is a breakline with only a few points that is triangulating to another breakline with lots of points. A classic example is at a curb return on a roadway where the crown of the roadway has a large stroking interval while the curb return has high density interval. Try inspecting your data for this situation where you see the jagged contours and densify the data by some means to correct it.

Re: Contour lines jagged, not smooth

MichaelGilham — Fri, 04 Sep 2009 21:41:30 GMT

Hi David,

can you post some sample data - so we can take a look?

Thanks,

Re: Contour lines jagged, not smooth

Dan Calistrat — Fri, 04 Sep 2009 21:03:52 GMT

It sounds as if the breaklines weren't picked up at all. Maybe post a before and after pic? Also in the DTM Toolbar, select Reports>Triangle Statistics which gives you a breakout of the exact # and type of features created in the TIN file. Make sure the report matches the existing graphics; uou can use MicroStation's powerselector to easily isolate the various feature types.

Re: Contour lines jagged, not smooth

David Conner — Fri, 04 Sep 2009 20:48:03 GMT

I think I just may have my expectations too high. I have tried ALL of the options available. My goal is to have the contours follow along as the break lines do. My break lines are all "clean" line segments and arcs. When the contours are created by GeoPak they are "jagged" b-splines. I don't mind that they are b-splines but they don't run straight nor are the curves smooth.

Re: Contour lines jagged, not smooth

MichaelGilham — Thu, 03 Sep 2009 01:19:18 GMT

Hi,

did you try drawing the contours with B-Spline smoothing enabled?

Its a smoothing option on the Load Features>Contours dialog.

It may help...