topic Re: Surface Contours in Civil 3D Forum

Surface Contours

LarryS23 — Thu, 09 Jul 2020 23:01:43 GMT

I am trying to create a surface with presentable counters. Notice in the picture attached how the minor contour just drops off. I have tried deleting lines and add points and not really getting anywhere. The elevations around the top vary note. Also when I tried to weed the feature line the drawing tends to crash.

Re: Surface Contours

rl_jackson — Thu, 09 Jul 2020 23:22:58 GMT

If the upper portion of you imiage is outside the limits of your survey you should go to the Surface Properties - Definition Tab and set the Use maximum triangle length to Yes and set a comfortable length based on your data spacing. I usually start with 100 and work from there. If your issue is the pull that is happening then I might consider deleting that point from the surface using the Surface Edits with the points and triangles on.

Re: Surface Contours

Joe-Bouza — Thu, 09 Jul 2020 23:48:50 GMT

looks like a bust in elevation from here. is this topo or FG?

Re: Surface Contours

LarryS23 — Fri, 10 Jul 2020 00:05:58 GMT

Supposed to FG. The FL elevations vary from 5 to -2. So this might be causing the issue? Not entirely sure

Re: Surface Contours

Joe-Bouza — Fri, 10 Jul 2020 01:43:49 GMT

the elevation values would not matter it where they are and how they relate to the others. I can see where I circle something is getting fouled up.

possible culprit another feature line under the design that is in the same site. Lets see the elevation editor of the toe..

can you post the file?

Re: Surface Contours

LarryS23 — Fri, 10 Jul 2020 01:53:59 GMT

Could be...I’ll check in the morning about the FL suggestion. Will post the file if that doesn’t solve the issue

Re: Surface Contours

LarryS23 — Fri, 10 Jul 2020 14:00:14 GMT

I attached the layout of the pond. I used grading creation tools and a stepped offset to create this layout. Working on trying to create the surface from this but am running into difficulties as I said before with the contours.

Re: Surface Contours

Joe-Bouza — Fri, 10 Jul 2020 15:33:34 GMT

Hi Larry @LarryS23 the file has some corruption and will not open on my end.

Run recover/ audit purge on your end and repost if possible

Re: Surface Contours

LarryS23 — Fri, 10 Jul 2020 15:50:56 GMT

I attached the dwg. I added some low spots to fix the bottom of the pond contours. The outside contours near the top still do not look as presentable as I want.

Re: Surface Contours

Joe-Bouza — Fri, 10 Jul 2020 16:33:23 GMT

you have something weird going on with your feature line for top of slope

Triangle are PVI circle are elevation point. Green triangles and circles are shared point with other feature lines in the same site. white triangle mean another feature line is crossing . I cannot find these shared feature line points or crossing. did you create the top of slope FL from drawing objects? if yes there may have been overlapping geometry that is internally effecting the feature line

https://knowledge.autodesk.com/support/civil-3d/learn-explore/caas/CloudHelp/cloudhelp/2018/ENU/Civil3D-UserGuide/files/GUID-3DADB332-93E5-499E-9D36-D6EAE264BF16-htm.html

Re: Surface Contours

LarryS23 — Fri, 10 Jul 2020 16:39:31 GMT

I created the top of the FL using the stepped offset command.

Re: Surface Contours

Joe-Bouza — Fri, 10 Jul 2020 16:48:24 GMT

Move it to a different site and you will see the split points and shared point marks go away. this has to be effecting the pond.

The stepped offset was from the Grading FL? That should yields a clean FL with no effects from other FL.. This is puzzling

Re: Surface Contours

Joe-Bouza — Fri, 10 Jul 2020 16:54:24 GMT

Whhat is the top of the grading based on? there are many irregularly space elevation points. Is this line starting at EG?

Re: Surface Contours

LarryS23 — Fri, 10 Jul 2020 16:59:50 GMT

The middle FL is the one that started at EG.

Re: Surface Contours

Joe-Bouza — Fri, 10 Jul 2020 17:21:56 GMT

thats what I figured. I cant put my finger on anything other then the shared and split points in the top of slope feature line.

part of wants to blame the geometry ( please take no offense ) When I see grading projection at inside corner overlap I get worried. I try to get my geometry curved in these area that would project to a smooth inside radius. Also I try to minimize the elevation points. for instance in the lower left of the pond the elevation points are very clustered together . I try to normalize the elevations so the grading isn't make so many different slope projections so close together.

I thing the geometry of this feature line is collapsing on it self when projected and stepped offset.

Re: Surface Contours

LarryS23 — Fri, 10 Jul 2020 17:58:56 GMT

Yeah that's what I am thinking too in regards to the geometry

Re: Surface Contours

Joe-Bouza — Fri, 10 Jul 2020 18:57:40 GMT

you are a little short of EG on the east side

I did a redo geometry of the feature lines and things look pretty good except the tie to existing on the east side

Re: Surface Contours

Joe-Bouza — Fri, 10 Jul 2020 19:06:52 GMT

I guessed what the river bank elevation is and extended EG . now the grading is complete

Re: Surface Contours

LarryS23 — Fri, 10 Jul 2020 19:15:38 GMT

Thank you. I noticed that too in regards to the pond being outside the EG. I changed the top of my pond to elevation +1 all around because that’s what the design I found out today is instead of taking the top of the pond at the EG elevation. Had to change some contours and add some points but it was much easier to work with because the geometry of the FLs were not so complex. Will look at your drawing. Again thank you all for the help

Re: Surface Contours

Joe-Bouza — Fri, 10 Jul 2020 22:45:56 GMT

HTH