3D Polyline from COGO Points?

[cbriana]

i am trying to get 3d polylines of some alignments that i have already defined. I created cogo points from the alignments but i was wondering if there was a way to get a 3d polyline through the points without having to click each point manually. (ie entering a point range and having autocad generate a 3d polyline for you.)

I am using AutoCAD 2008 with Land Desktop Companion

Thanks

[rustysilo]

Do you mean a 3D polyline representing your vertical alignment (profile)?

[cbriana]

no, not a profile. i want a 3d polyline along the alignment in the plan view that has elevations corresponding to the elevations defined in the vertical alignment

[rustysilo]

Yeah that's what I meant. If you have a profile with a vertical alignment defined then yes you can do this. The process is as follows (assuming you have already created cogo points of the vertical alignment):

1. Open the Terrain Model Explorer
2. Create a surface
3. Expand the surface data
4. Right-click on breaklines
5. Define by Point Numbers
6. Key in the first point number, dash, last point number
7. Adore your work

[cbriana]

Thank You. That was exactly what i needed.

[rpduenas]

If i'm following your instructions, you would then have a surface created along your centerline. How would you model the cross slope of the alignment (if it were a roadway) and place an accurate boundary on the surface?

[rustysilo]

Use stepped offsets of the 3d polyline you just created in the previous steps. That's one way to do it anyway. You could also use the roadway design tools available in the Civil Design module if you have it loaded.

Much easier in Civil 3d.