Extending a TIN or DTM Surface

[Paul Mc]

I need to extend a TIN model but dont know if this is even possible. My TIN is a road base which has been created using points. I need to extend (or offset the curb line out another 2' and have the TIN model also extend to that line. The crossfall of the roadway needs to stay consisant. I can extend no problem but the extention becomes flat.

 

Thanks for any help.

[BIGAL]

Generally speaking any road design must be contained fully within a TIN all sorts of problems start when you are calculating batter edges etc in never never land. A simple fix is to add dummy pts outside the full tin say at least 4 at a suitable height for the location. We would normally string an edge forcing the levels to match the edge. We use a 3rd party add on to CIV3d and it will extend the batter even if a TIN does not exist.

[CyberAngel]

If your boundary elevations are only approximate (and they'd have to be I guess), you could draw breaklines along the new boundaries and add them to the surface. That saves adding bunches of points, which would be equally approximate.

[Paul Mc]

I usually use the breakline method. Just looking for a quicker solution.

Thanks for the input.