Break a line at a 3D intersection.

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Sam Lemon posted 03-05-2021 10:04

Hello

I'm trying to create some river cross sections in TBC.

To generate the water level I want to create a narrow surface at a set elevation however I don't want this surface to extend beyond the river banks.

This exercise has highlighted in interesting issue, I cannot break the blue line at the 3D intersection with the brown line. Clip, break and trim only work at the lines vertices points, how can I create a vertex at this 3D position?

Any ideas on how this can be achieved?

Many Thanks

Sam

Marian Plucinski posted 03-07-2021 19:55

1) Create Surface for water level
2) Create Surface for river banks
3) Surfaces -> Surface Intersect Lines

Marian Plucinski posted 03-07-2021 20:51

2nd option would be to use Trimble's Slope - Slope macro:

Alan Sharp posted 03-09-2021 12:05

The challenge with this in TBC standard is that the two lines are colinear - ie they occupy the same space and TBC works primarily in 2D to determine when two lines intersect. To create the intersection point of two colinear lines requires a dedicated command to achieve that. What you can do however is the following

1) Select line 1. Right click and open the Profile Viewer for that line.
2) Select line 2 and then hold the shift key down while you select Profile Viewer for Line 2

This will open the second lines profile in the same viewer as line 1. You can clearly see the intersection of the two lines- you can exaggerate the profile view and then you can break the line at the intersection of the two profiles or add a VPI. Note you have to edit the Line used to initiate the Profile view not the second line that is a proxy in the profile view. It will be pretty accurate - you can zoom right in and typically select to a mm or better.

A dedicated command could be created to do this if needed I am sure, however when you start implementing Vertical Curves in the lines it might not be so easy.

Alan