Extend 3D line to an existing surface

[LThomas]

Is there a way to extend a 3d line to meet an existing surface (.tin, grd, etc)? I am trying to draw my cut/fill slopes for a road job from the edge of my typical section to the existing surface.

[R Stillwell]

The only way I have found to do it with out of the box Carlson is to extend the line at the slope I want it to be to a point beyond where I think it will intersect and then SURFBREAK command to have it break it at the surface.

If you are handy with VLisp. You can use their API to create a program that will do it. I've written one but I can't give it to you because it is the property of the company I work for. It can be done though.

I'm hoping that maybe the 2012 Carlson will have a better way of doing this. I can offset a 3D Polyline to intersect a surface in a matter of seconds with Offset3d. My custom program takes longer to find the intersection using their API. So I would think they could come up with something that would be a lot quicker than the options we currently have available.

[Nava Ran]

Define the slopes for cut anf fill in Design Template and get automatically the intersections with the surface.

[LThomas]

Yes I understand how to use the Design Template, but occasionally it is necessary to add some detail in a radius or other special circumstance where it would be much quicker to just be able to project a single line or two to the surface if possible.

[Nava Ran]

Try:
3D Data>3D Polyline Utilities>Break 3D Polyline by Surface

[TerryS]

1. Use Offset 3d Polyline (command: offset3d) and choose the Surface option

2. Use Design Pad Template (command: pad)

[R Stillwell]

1. Use Offset 3d Polyline (command: offset3d) and choose the Surface option

2. Use Design Pad Template (command: pad)

Those commands will not do what the poster wants them to do.

The OP wants to extend a 3DPolyline to a surface. Not offset the 3DPolyline.

I suppose one could draw a 3DPolyline perpendicular to the one to be extended and Offset3D that line. But that's a lot of steps to do something that shouldn't be much more difficult than using the Extend command.