AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

Reply
Valued Contributor
tony1978
Posts: 92
Registered: ‎02-01-2007
Message 1 of 8 (466 Views)

Surface Contour Extraction

466 Views, 7 Replies
04-27-2011 08:28 PM

I have a drawing set to UTM83 Zone 14 Meters and my drawing units is set to meters also. I created my surface from my point cloud. When i do the contour extract feature (surface object extract), the contours elevation is in the wrong datum or elevation? The surface contour is 620 but the same extracted contour says 188.97? Curious why this happens. It seems to me that it is back calculate elevation or daturm to a different coodinate system.

 

tony

senior design tech

 

Valued Contributor
Feckit
Posts: 64
Registered: ‎03-19-2009
Message 2 of 8 (457 Views)

Re: Surface Contour Extraction

04-27-2011 09:51 PM in reply to: tony1978

Tony

 

You've got a setting somewhere set to feet.  Your drawing units are probably set to meters however I'm guessing that the elevation setting under ambient settings is set to feet.  Multiplication of 620 by 0.3048 is 188.976, with 0.3048 being the conversion factor from feet to meters.

 

Kind Regards

Feckit

Valued Contributor
tony1978
Posts: 92
Registered: ‎02-01-2007
Message 3 of 8 (439 Views)

Re: Surface Contour Extraction

04-28-2011 06:07 AM in reply to: Feckit

ok I will change my drawing units to feet and my surface units to meters. Hopefully that will work. So when i extract my contours it should be on the right daturm or elevation.Tks Feckit

 

Tony

Senior Design Tech

www.tonyscivil3dworld.blogspot.com

Distinguished Mentor
OMCUSNR
Posts: 506
Registered: ‎04-28-2010
Message 4 of 8 (420 Views)

Re: Surface Contour Extraction

04-28-2011 07:43 AM in reply to: tony1978

Tony,

 

When you started this drawing, what template did you use?  It's REALLY important to start with a METRIC DWT, if you're going to work in metric values.  Just setting units to metric in an imperial template cna hose things up.

 

Reid

Homebuilt box: I5-2500k, MSI P67A-GD65, 12gig DDR3 1600 ram, ASUS ENGTX460 Video card, WD Velociraptor WD4500HLHX HD, Win 7 64 pro.
Valued Contributor
tony1978
Posts: 92
Registered: ‎02-01-2007
Message 5 of 8 (397 Views)

Re: Surface Contour Extraction

04-28-2011 12:16 PM in reply to: tony1978

I'm using the company std template that is imperial. Ok i will definately try this out then.

 

Tony

Senior Design Tech

www.tonyscivil3dworld.blogspot.com

 

Member
lbabic
Posts: 5
Registered: ‎02-21-2012
Message 6 of 8 (224 Views)

Re: Surface Contour Extraction

01-24-2013 04:53 AM in reply to: tony1978

I have a question regarding surface contour extraction in Civil 3d 2012.

 

Based on specifications by our investor we need to deliver contour lines that have intervals like this:

Major 5 m

Minor 1 m

Auxiliary 0.5 m.

 

Defining the first two was easy, auxiliary required some effort (I created user defined contour lines; fortunately there weren't too many otherwise I would have done it differently). In surface style I assigned each type with a different layer to make it easier to select each type.

Anyway, when extracting contours from the surface, using the above mentioned method I discovered that extracted minor contour lines also included my user defined (auxiliary, at each X.5 m) lines, thus overlapping the actual, and also exported, user defined contour lines. Does anyone know why this happens, and if there is any way to resolve the issue other than removing the user contours from surface definition and then exporting the minor contours, or subsequently deleting excessive minor contours by hand (which I would never do)?

 

Best regards

*Expert Elite*
troma
Posts: 2,525
Registered: ‎05-21-2008
Message 7 of 8 (219 Views)

Re: Surface Contour Extraction

01-24-2013 06:04 AM in reply to: lbabic

You would normally be better off starting a new thread rather than resurrecting a two-year-old irrelevant conversation.

 

I don't know why this is happening, but have you tried turning off the user contours, extracting the major and minor, and then turning on only the user contours and extracting them?  If that doesn't work I would simply define the Major as 1.0m and the Minor as 0.5m and extract them like that.  Then go and find the 5.0m contours and put them on a different layer.


Credit where credit is due! Give kudos or accept as solution whenever you can.

Member
lbabic
Posts: 5
Registered: ‎02-21-2012
Message 8 of 8 (204 Views)

Re: Surface Contour Extraction

01-24-2013 10:32 AM in reply to: tony1978

Dear Troma,

 

"You would normally be better off starting a new thread rather than resurrecting a two-year-old irrelevant conversation."

 

First of all: tip dully noted.

 

"I don't know why this is happening, but have you tried turning off the user contours, extracting the major and minor, and then turning on only the user contours and extracting them?  If that doesn't work I would simply define the Major as 1.0m and the Minor as 0.5m and extract them like that.  Then go and find the 5.0m contours and put them on a different layer."

 

Second: I can think of many ways to resolve the problem relatively quickly and efficiently. What I don't understand is why does export minor contours necessarily include user contours (whether they are displayed or not doesn't matter as long as they are created/defined in surface properties as I have already discovered). Since I will need this a lot in my project and will thus encounter the same issue many times during this project I would prefer to have autocad do what it (by all reasoning) should do, and that is why I sought help here. If there is no solution I will be a bit disappointed but at least I will have tried my best to find one.


Maybe if You think of something else or know someone else who could help, You could let me know.

 

Best regards

Post to the Community

Have questions about Autodesk products? Ask the community.

New Post
Announcements
Do you have 60 seconds to spare? The Autodesk Community Team is revamping our site ranking system and we want your feedback! Please click here to launch the 5 question survey. As always your input is greatly appreciated.