How do you draw a surface from scratch????

[Anonymous]

Hi, I'm trying to draw a surface out of a digitized pdf plan. I have my exisiting contour lines plan in dwg format, the plan is already scaled. My contour lines are 2D polylines. I have no survey data, coordinates, or points.

How can I get a surface from here? how can i transform my 2D polylines into contour lines? can I add a "z" elevation to each of my 2D polylines (contour lines)?

Please advise.

[sboon · Accepted solution]

Ctrl-1 to turn on the Properties palette, select the polylines one at a time and set the elevation for each.

Create a new empty surface.  Expand the Definition group within the new surface and right-click the contours option to add the polylines.

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

[autoMick · Accepted solution]

You basically answered your own question...

As sboon says.. right click Surfaces in the Prospector, create a new surface then open up the surface 'tree' to see the definition items. then add breaklines. 

A curious thing about is that you can actually add 3D polylines (nodes at different elevations) as 'contours' and the surface will still be created correctly.

- Mick

[neilyj666]

There is also a tool in the UKIE country kit that will allow you to specify a starting elevation and interval and the polylines are raised automatically.

There is also a lsp here that does the same thing (untested) http://www.cadstudio.cz/en/download.asp?file=CHELEV.LSP+-+sets+contour+elevations+%28LISP+...

[antoniovinci]

Deserved kudo by me, man!

Another "elevating" tool is embedded in the free Cadtools @ glamsen.se

[jmayo-EE]

On top of the excellent advice already provided please let me add this.

1. In the Modify tab of the Ribbon, click the arrow to drop down the Design Panel and choose Edit Polyline Elevations. This is probable not as nifty as the addons but it is in the program.

2. If you digitize the contours you should also digitize any spot elevations on the plan. Add cogo points at the locations and assign the correct elevation. Put these in a point group and add the point group to the surface definition before the contours. This will help insure a closer match of the surface model to the plan.  

[troma]

In addition again to all this great advice, I'm gonna post the link I always do when someone is building a surface from contours. Have a read:

https://civil3dplus.wordpress.com/2011/08/13/adding-contours-to-a-surface-youre-doing-it-wrong/

[walterlewinski]

Also, remember to set "Copy deleted dependent objects" to "yes"

If you don't do this and erase one of the original polylines, your surface will update and change.

see image attached.