Trim or Extend line to surface

[Anonymous]

Hi, I am trying to trim or extend a line at the point where it contacts a surface. The surface was created by extruding another line. In the attached image, I want to be able to trim the vertical line right where it touches the surface at the red curve. 

The regular trim command does not work. Thanks

[Pointdump]

Shawna,

Not sure I understand. Is this a Civil 3D Surface?

Dave

[Anonymous]

Yes, it's a 3D surface that was created by extruding a 3D polyline. 

[Pointdump]

Shawna,

The only thing I can think of would be to drape a Feature Line on your Surface and use the FL to Trim/Extend your line to.

Dave

[doni49]

1. Turn on the surface triangles.
2. The triangles will help you identify the vertices of the red line. 
3. Zoom in so that you see the vertex on each side of the line
4. Draw a line beween those two vertices and use that line as your cut line in the trim.  Then delete your cut line.
5. Turn off the surface triangles.

[Anonymous · Accepted solution]

I wasn't able to find a solution in any of the suggested manners. I have found that it is possible to imprint the surface onto the line and then I can break the line at the surface. This is the only solution that has worked well, however tedious. 

[Anonymous]

@ShawnaK,

Try this as a work-around:

1. Extrude (EXTRUDE) your line (vertical in your picture) to some small distance (e.g. 0.1; direction doesn't matter; can't be a feature line - copy/paste and explode if necessary).

2. Use SURFTRIM to trim the newly extruded solid (If your trimming surface is a TIN surface, see supplemental steps below 2a, 2b, etc.).

*You may have to use this command twice as sometimes a small tail is left after the trim. You can check by running inquiry to check if the grip elevation and surface elevation match or by viewing the trimmed solid and surface in the object viewer.

3. Drag the endpoint grip of your line to coincide with the newly trimmed end of the extruded surface.

4. Delete the extruded vertical surface.

For TIN Surfaces:

2a. Identify the approximate crossing point.

2b. Turn on Triangles in the TIN Surface Style.

2c. Use 3DFACE to create a plane that will intersect with your line. If you're not sure exactly which triangle to use, you can repeat the 3DFACE command with the surrounding triangles.

2d. Select your newly create 3D Faces, and use CONVTOSURFACE to convert them to surfaces.

Move on to step 3.

It would be nice if there was a snap for the intersection of a line and a surface, or the ability to use surfaces to trim lines, but this isn't too bad. I use it to find where pipes penetrate the sidewalls of earthen basins.

Grant

[gherrmanRQ549]

Recently, I've been using the following procedure:

1. "SWEEP" a circle along the pipe path.

*Feature lines can't be used for "SWEEP" path. Object used for used sweep path is deleted, so make sure to make a copy if you want to retain the 3D polyline.

2. Turn on Triangles in the TIN Surface Style.

3. Use 3DFACE to create a plane from the TIN triangle that will intersect with your line. If you're not sure exactly which triangle to use, you can repeat the 3DFACE command with the surrounding triangles.

4. "SLICE" the resulting 3D solid. Use the 3points option in the command to define the slicing plane using the corners of the TIN triangle previously identified.

5. Drag your pipe line endpoint grip to the sliced solid.