Preventing Surface Interpolation Between Triangles/Points

[Jamie_Carroll9SC46]

Hi,

When creating a surface from Topo Survey Triangulation, is there a way to stop surfaces interpolating across locations where no data points have been taken? I.e. Surface isn't generated at locations where no survey points/triangles are.

Example shown below:

Blue = Survey Triangulation

Pink = Civil3D Surface using Survey Triangulation 

I don't want the surface to infill locations without data, so currently I would manually remove these lines. Is there a way to limit the survey data automatically? 

[brian.strandberg]

You have a couple of options.

#1 - Add a boundary to those areas.

#2 - Under the Surface Definition Tab, Set the Maximum Triangle length to a value that works for you.

#3 - I usually don't recommend this, but you can use the surface edit tools such as Delete Line to create a hole in those areas.

[Jamie_Carroll9SC46]

Hi Brian,

Thanks for the reply. 

What boundaries do you use for internal areas you be removed? 

The issue with the maximum triangle length is the distance between some of the survey points is larger than the distance being interpolated so I'd still need to set internal boundaries or delete lines. 

[brian.strandberg]

I would use a hide boundary for each of those areas, it removes that area from the surface.  If you try to get a point elevation in that area it will return ???.

If you check non-destructive breakline, the TIN will follow the boundary exactly, if you don't it will hide the triangles completely within the boundary.  Put the boundary polyline on a non-plotting layer.

Thanks, hope this helps.