Offset Alignment Issue

[davich787]

Hello - I'm having an issue when creating offset alignments for a corridor, the issue being that only one side is being created and the other fails to offset.

I have never encountered this issue before and wondering if anyone had and what I should be doing to correct this?

Thanks very much.

[MMcCall402]

Possibly a small geometry issue with the alignment.

Were there any yellow triangle warning messages along the alignment that were turned off?

You could temporarily break it into smaller pieces to narrow down where the issue is. 

[sboon · Accepted solution]

Try creating an offset alignment that is limited to a simple tangent segment of the master centerline.  If that works then use the grips to extend it until you can identify the problem area.

[fcernst · Accepted solution]

Typically a couple PI’s too close together.. can calculate the convex offset side but not the other concave side.. so start looking in the concave areas on that side. 

Think bowtie issues..

[davich787]

Hi - Thanks very much for these replies, I really appreciate it.

I used a combination of all the above suggestions to locate the problem area, and it was ultimately a couple of PIs on a concave section that was causing the problem. Got rid of those and it was all good.

Thanks again.

[fcernst]

Good.. it would be good for the software to show the bow tie problems during the Offset Alignment workflow.. @TimYarris 

[TimYarris]

Great feedback. Would you folks expect this type of notification to be visible in canvas (as warning glyphs), in editing tables like Panorama and ALP, or all of the above? 

[sboon]

In this case the offset alignment would fail to create, so there would be no panorama or editing table to see.  The issue is that the command fails with no warning or error message.  It would be helpful to see at least a dialog that explained the reason for the failure, and maybe a highlight of the relevant segment on the master centerline.

[fcernst]

Show temporary Glyph vectors demonstrating the bowtie problem(s).