# Thread: Surface boundary causes surface errors

1. ## Surface boundary causes surface errors

Hi,
Can someone give me some work around on the following problem:
I created a surface from a corridor and I created a boundary which needs to run inside the surface in certain areas to outline a proposed headwall.
I noticed that as long as the boundary follows the boundary created by Civil3D the surface acts nicely but if the boundary runs inside the surface, Civil 3d starts to cut out swatches within the surface. see attached JPG files

2. ## Re: Surface boundary causes surface errors

Originally Posted by cblendermann.91943
Hi,
Can someone give me some work around on the following problem:
I created a surface from a corridor and I created a boundary which needs to run inside the surface in certain areas to outline a proposed headwall.
I noticed that as long as the boundary follows the boundary created by Civil3D the surface acts nicely but if the boundary runs inside the surface, Civil 3d starts to cut out swatches within the surface. see attached JPG files
Just a guess since I do not use Civil 3D. The boundary you are using is removing points from your surface. Can you interpolate points around your boundary? This should provide your surface with points to finish the contours you are looking for.

I hope that makes sense. I don't know the Civil 3D terminology to better explain it.

3. ## Re: Surface boundary causes surface errors

When creating the boundary are you using destructive breaklines? It would appear that the breaklines being created by the new boundary are non-destructive, the naming scheme of the breaklines tend to be confusing, making most people think the opposite reaction will take place when making this choice.

4. ## Re: Surface boundary causes surface errors

Originally Posted by Christian Barrett
When creating the boundary are you using destructive breaklines? It would appear that the breaklines being created by the new boundary are non-destructive, the naming scheme of the breaklines tend to be confusing, making most people think the opposite reaction will take place when making this choice.
Christian,
Thank you for the tip. I removed the boundary from my surface and reatached it and checked the box for "non-destructive breakline" which then resulted in a properly bound /cut back surface.
Have a great day
Cord B

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