Combining surfaces

[Anonymous]

I am combining surfaces in civil 3d for a landfill site. I have a ground line and another surface I want to use as the liner. How do I create a combined surface only of the points which are at the top as this will be my new surface. This will be my finish ground line.

[Jeew-m]

Dear Friend,

Usually combining surfaces can be achieved by paste surface option in Civil 3D. Refer this video and see if it works for you.

Thanks

[Anonymous]

Hi, Please see attached. I need to model a surface highlighted in blue. How would this be done? Its a combination of the NGL and the surface of a liner.

[Mike.M.Carlson]

No attachment?

[BushW]

Hello @Anonymous

No file posted but, here are the steps to merge surfaces.

1. On the Civil 3D Toolspace, click on "Prospector" tab.
2. Right mouse click on "Surfaces" and create a new surface.
3. Expand the "Definition" subfeature for that new surface and right click on "Edits".
4. Click "Paste Surface" and chose the original surface.
5. Change the new surfaces style to display.

I hope this helps!

Please select the ‘Accept as Solution’ button if my post solves your issue or answers your question so, other Community members may benefit and thank you for doing so.

Best Regards,

Wendell

[Anonymous]

Oops sorry

[Anonymous]

Hi,

But that option shows the last added displayed at the top. I practically want the cut and fill surface.

Thanks.

[Mike.M.Carlson]

Hi-

It sounds like you just need to create a TIN volume surface then.  If so, go to the Analyze Ribbon and choose Volume Dashboard.  From there create a new TIN Volume Surface.  The CUT / FILL / NET will be shown in the Volume Dashboard Panorama.

I hope this helps.

[BushW]

Hello @Anonymous

Did @Mike.M.Carlson resolve your issue with his suggestions? If so, please reward the post that worked with an ‘Accepted as Solution’ or Kudos, and please also mark a post or posts as Accepted Solution(s) that resolved the issue or answered your question so, other Community members may benefit and thank you for doing so.

Best Regards,

Wendell

[Anonymous]

Hi,

When you create a volume TIN surface, it adds the new surface at a zero elevation, due to the difference in the surface elevations from the surfaces which are compared. However, i need this surface to be at the difference in elevations which these two surfaces are. I have tried using the minimum distance between surfaces command under the Ground data panel found in the Analyze tab and created a surface using this boundary made out of the polyline generated.

Hope this makes sense.

[Wojtek_Garczewski · Accepted solution]

Hi all, 

It might not be your case, but recently I've written this sample steps to follow:

1. To avoid comparing and analyzing too much data, consider clipping a larger surface with a boundary exported from the smaller one. Thanks to that we are comparing the same area.
2. Select both surfaces and change surface style to display Points.
3. Select "A" surface. In the Ribbon, go to Surface Tools -> Extract from Surface -> Extract Objects from Surface. In the Extract Objects from Surface select Points only and OK.
4. Repeat step 3 with the "B" surface.
5. Once all points are extracted from both surfaces, go to the Home tab -> Points -> Convert AutoCAD Points. Select all extracted points (from steps 3 and 4), and press enter as long as the command finishes converting points to COGO Points. This is the most time-consuming exercise, and it may take some time depending on a number of points.
6. Once done, in the Toolspace, go to Point Groups -> _All Points, then click on the list and select all points with combination CTRL+A
7. Right-click and "Elevation from Surface..." select "A" surface.
8. Right-click again and "Export...". Save file as csv file.
9. Repeat steps from 6 to 8 for "B" surface. 
10. Once both data sets for both surface are exported, within Excel, you can just use MIN/MAX function to take the lowest/highest elevation from the two surfaces and then write out an x,y,z or csv file, and import back into Civil 3D.
11. Delete old COGO Points from Civil 3D and import new ones with MIN/MAX values. Creating a new surface based on imported points should give expected results. To increase accuracy I suggest to use MINIMUMDISTBETWEENSURFACES command. This command will extract 3D Polylines in places where "A" and "B" surfaces are intersecting. Add generated Polylines as a breaklines.

Additionally, please see screencast that shows the steps. Some moments were fast-forwarded. Here: 

• Marge surfaces with lower levels in Civil 3D

Please see this forum thread as well: Sort points in relationship to 3D surface, which contains some nice solutions too. 

Thanks,
Wojtek

[JamesMaeding]

@Wojtek_Garczewski 

I'm a year late to this discussion, but clever approach.

My thought on this is to go ahead and make a tin volume surface, and use its points to form the final "upper" or "lower" surface. That tin vol surface will naturally have tris forming the areas the surfaces intersect, and then a whole lot more. So reassigning elevations to them by min or max would give a better result, though heavier.

All this is essentially ways of draping one surface over another, or min/max of two or three or four....

Ideally we would just find the cut/fill boundaries between the surfaces and splice together using those.

I bet Carlson has that...