Civil3D - Alignment endpoint affecting surface contours

[david]

For eg - creating a road corridor. create alignment and proile etc.

Make corridor shorter than the alignment...

The position of the endpoint of the alignment causes a massive glitch in the surface contours.

You have to reposition the endpoint away from any design elements to stop it occurring.

Wondering why a totally 2D design element, related to a specific item/corridor, would be interracting with my surfaces and other design elements?

Anyone else having this issue, and is there a solution?

Thanks

[Joe-Bouza]

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I dont think it is the position of the alignment end point. I belive it is the profile is a wee shy of the alignment end point. could be a very very small distance too.

without moving the alignment change the range in the corridor parameter to see if this is in fact the case.

Is the alignment in the same site as the grading?

[tscheevel]

It appears that you have a zero elevation somewhere. If your design profile ends before the alignment and corridor end, the corridor will dive to zero elevation. Check for zero elevation points or gaps in your target surface.

[owenmull]

To elaborate on previous messages:

Also, make sure that the end of your profile ties with the edge of your grading surface (at end station of corridor) and that said profile's elevation matches at this point, as opposed to matching your target at the end of the alignment. If your profile doesnt tie at this point, that could be why there is a difference.

Why not simply end your Alignment right at your tie in spot?

I would take a very close look at your profile and make sure it ties and also that it runs the full length of the corridor and/or alignment, ensuring the corridor has no '0' elevations anywhere.

[david]

Yes it happens when the alignment ends above a grading. SO perhaps the alignment is interracting with the grading? Why it would do this I dont know.

[david]

That surface (on the attached example) is actually the existing ground plus the grading surface combined into 1 surface..

[david]

Thanks tscheevel.. Surface is fine.. Its is only occutrring where I have a grading. No zero elevations.. its coming from teh alignment.. which in theory has no elevations. This happens before you create a profile.. and stays after your profile is created.

[david]

Thanks, It wont do it if I stop the alignment before it reaches the daylight of the grading, or if I run the alignment right across the grading, through to past the other side/daylight. It does it as soon as you create the alignment, even before you've created the profile. Doesn't make much sense to me as to why it would do this. Its just an enpoint of a supposedly purely z dimensionally free line.

[owenmull]

Based on your picture, it looks as though you have merged your grading surface with your existing ground surface. If not, create a merged surface of the two, and tell your corridor to target that surface, once again assuming your profile ties with the edge of your grading surface. Perhaps what is going on is you are targeting the existing ground surface, and of course causing a discrepency right where the corridor and grading surface meet, like in the pic.

Look into your target surfaces.

[david]

Thanks Owen,

The alignment changes/effects the contours, even before the profile, and corridor have been created.

Try it.

Its happens to me on every job. I have to make sure the end of the profile doesnt lie above any gradings or corridors.

It should be a purely 2D element, in my mind anyway.

Perhaps I am just lucky and no one else has this problem?

Only solution is to use gradings instead of corridors.

Or forget about Civil3d and go back to Powercivil.

[Jeff_M]

David, you never responded to Joe (the first response in this thread), and I believe this is the problem you are experiencing. Alignments and Featurelines (and Parcel lines, too) affect each other when in the same site. Here's a short video demonstrating this:

[david]

Hi Jeff_M. Thanks for reply.

I did reply to everyone, however it was with quick reply.. This is my first go on the forum.

Is there a video showing how to stop it happening?

Can we call that a bug?

An alignment is just that, an alignment.. no surfaces are targeted, no corridor or 3D surface, or 3D anything is created.

And yet Civil3D deems it necessary to use your alignment as a 3D featureline set at 0?? elevation.

What if I want to run a corridor over the top of a grading? Or have corridors that cross eachother.. even just for initial modelling / design purposes.

Cant do it without a massive blob of contours appearing. Which in turn appears on the profile view. Its not helpful.

Whats the workaround? Keep creating seperate sites with each iteration of the surface, none of which are linked/dynamic, as otherwise, if they are linked and dynamic your alignment will create this kind of problem anytime its sitting over another design element?

If there's a solution to this I'd love to know what it is.

Thanks

[Jeff_M · Accepted solution]

The solution is to place featurelines, gradings, and alignments in separate sites. Then they will no longer interact with each other.

[Joe-Bouza]

Check again. I think you missed me 🙂

[Joe-Bouza]

Thanks

[owenmull]

Jeff_M has the solution. As he said, objects of the same site will interact. Simply create a new Site for your alignment, rebuild everything and that should solve it.

[david]

Hi Joe,

Apologies for that. Thanks though. All help very much appreciated.

[david]

Hi Owen.

Have done as you suggested. Never occurred to me before to create sites for the various components within the project.

All good and problem solved.

I still think the behaviour for an alignment alone to affect the contours is a bug!

best regards

David

[david]

Hi Jeff,

Thanks for your assistance. Problem solved!

Much appreciated.

regards

David

[Joe-Bouza]

How bout that <G>