How to change border of Tin Surface

[ammTJB47]

I have a surface in Civil that i made from the 3d lines that are in white in the picture. I used those points to create a Tin surface around them. Civil then automatically created a border around them (Yellow line). The border is not correct and does not follow the surface at all. I have tried to add boundaries in the surface prospector tab, but I keep getting error message (shown in picture).

Can anyone help me to get the right border around my surface?

[Pointdump]

Hi Alex,
"The border is not correct and does not follow the surface at all."
More details please. It would help if you could post your drawing. Have you tried using Maximum Triangle Length?
Dave

[ammTJB47]

I can post my Civil file.  no idea what triangle length is.

[Joe-Bouza]

you have some options. In the surface build properties you can limit the length of triangles. this can be tricky but both understanding your data and or trial and error will get you better.

you can also draw a poly lint boundary to the determined limits and add as outer boundary

[ammTJB47]

Polyline doesnt work, it still bugs out.

[Joe-Bouza]

don't be so detailed you don't need arcs or gnats-a$$ it. a general pline that crosses the triangles you do not need.

super important: never collapse pline vertices on itself EVER

[ammTJB47]

The surface the way it is, is how I need it to be. All the triangles aren't triangles they are polylines from the surface giving the surface its geometry and point elevations.  Without those lines I don't have a correct surface.

[neilyj666 · Accepted solution]

@ammTJB47 the red polyline boundary is horrendous - self intersecting and with bulges etc.

I ran OVERKILL on it, converted to a 3D polyline, converted back to a 2D polyline and added as an outer boundary and it worked with no problems

[brian.strandberg]

Were I often see issues with new users on this is they connect the last point back to the start point of the polyline, then input C to close the line.  This duplicates the last point and will make it illegal for the surface boundary.

Thanks.