AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

Reply
Member
sdrobs
Posts: 3
Registered: ‎04-10-2012
Message 1 of 8 (262 Views)
Accepted Solution

Invert Contours (Positive Elv to - Elv)

262 Views, 7 Replies
04-10-2012 11:48 AM

I have a contour map that i need to flip all the postive contours to negitive. So the Z cordinate for example is Elv 40 now i need to invert it to -40. I want to do this to the whole large contour map. ????

 

Shawn

*Expert Elite*
Alfred.NESWADBA
Posts: 8,962
Registered: ‎06-29-2007
Message 2 of 8 (260 Views)

Re: Invert Contours (Positive Elv to - Elv)

04-10-2012 11:50 AM in reply to: sdrobs

Hi,

 

set the UCS to look from the right side (or from front) and then mirror your contours.

 

- alfred -

-------------------------------------------------------------------------
Alfred NESWADBA
Ingenieur Studio HOLLAUS ... www.hollaus.at
-------------------------------------------------------------------------
Distinguished Mentor
thepworth
Posts: 525
Registered: ‎03-02-2011
Message 3 of 8 (246 Views)

Re: Invert Contours (Positive Elv to - Elv)

04-10-2012 12:59 PM in reply to: sdrobs

is it contour data or contours representing a TIN/DEM?

 

If its contours as CAD objects, you could use the Map3D side of C3D to perform a drawing query to multiply all contours by a (-1) value and then recreate the surface.  

 

I'm not a fan of surfaces from contours w/o the breaklines.  The software has gotten better, but there's still a loss.

 

The miserable brute-force way would be to export to xml and then replace the elevations with a "-" character.  dunno even where to approach that 


C3D 2011
Intel Xeon E5630@2.53Ghz
NVIDA Quadro NVS420 Dual Monitor
12GB Ram / Win7 Professional 64bit SP1
Member
sdrobs
Posts: 3
Registered: ‎04-10-2012
Message 4 of 8 (227 Views)

Re: Invert Contours (Positive Elv to - Elv)

04-10-2012 03:30 PM in reply to: sdrobs

Thank you, i will give that a try.

*Expert Elite*
BrianHailey
Posts: 2,768
Registered: ‎04-27-2005
Message 5 of 8 (218 Views)

Re: Invert Contours (Positive Elv to - Elv)

04-10-2012 04:11 PM in reply to: sdrobs

Create a surface from the contours (do all the minimizing flat area options, you can read why HERE) if it's not already a surface. Create a flat surface at elevation 0 that's totally encompasses your surface. Create a volume surface that compares your surface as the base surface and the 0 surface as the comparison surface. Have the volume surface display contours. Extract the contours from the surface (if you don't want to have the surface).

Brian Hailey
CAD-1.com
My Blog
Member
sdrobs
Posts: 3
Registered: ‎04-10-2012
Message 6 of 8 (217 Views)

Re: Invert Contours (Positive Elv to - Elv)

04-10-2012 04:14 PM in reply to: sdrobs

Thank you so much, that worked.

 

Shawn

Distinguished Mentor
thepworth
Posts: 525
Registered: ‎03-02-2011
Message 7 of 8 (206 Views)

Re: Invert Contours (Positive Elv to - Elv)

04-10-2012 08:49 PM in reply to: BrianHailey

Guess I was having a "blonde moment" when I didn't think of that one ealier - nice!


C3D 2011
Intel Xeon E5630@2.53Ghz
NVIDA Quadro NVS420 Dual Monitor
12GB Ram / Win7 Professional 64bit SP1
*Expert Elite*
BrianHailey
Posts: 2,768
Registered: ‎04-27-2005
Message 8 of 8 (194 Views)

Re: Invert Contours (Positive Elv to - Elv)

04-11-2012 07:27 AM in reply to: thepworth

It's a technique I used to use in LDT to help delineate watershed boundaries, create an inverted surface and use the water drop tool on it.

Brian Hailey
CAD-1.com
My Blog
Announcements
Are you familiar with the Autodesk Expert Elites? The Expert Elite program is made up of customers that help other customers by sharing knowledge and exemplifying an engaging style of collaboration. To learn more, please visit our Expert Elite website.
Need installation help?

Start with some of our most frequented solutions or visit the Installation and Licensing Forum to get help installing your software.