3dpoly arc

[jamesbarnett]

Guys I am trying to draw up a topo, but I don't know how to draw a 3d arc for my curbs. Only the gutter line was shot so I need to be able to offset the arc horizontally and vertically. It seems the consensus is to use the feature line, but I can't get it to even look close with any of the compound cuves. 

[rkmcswain]

You're on the right track using a feature line. What is it about one that you can't get to work?

[jamesbarnett]

When I use a Feature to create complex curves it doesn't work out very good unless I only use 3 points for each arc. If I go over the same points with a spline it looks like it should.

[jamesbarnett]

I also forgot to mention the arc doesn't use the second pnt to calc the elevation on either.

[troma]

Not sure if you may have to go back and add an elevation point at the second point to get the z added to the feature line.

[Neilw_05]

It's not uncommon to find as-built curbs that are not true arcs. When it comes to modeling them your best option is to approximate them with compound curves as you have been doing. Unless there is a need to be very precise you can likely get by without using more than a couple of arcs. Featurelines work better than polylines since they don't need to be segmented along curves as do 3D polylines.

C3D modeling tools do not support splines (except as contours) so avoid using them.