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Featureline editing questions (Rookie level)

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Message 1 of 14
jeff_rivers
1016 Views, 13 Replies

Featureline editing questions (Rookie level)

I'm using featurelines to develop several proposed curb-sidewalk-ADA ramp designs.  I don't have a lot of experience with featurelines but I think I'm getting the hang of them, and it's definitely better than creating multiple alignments and profiles for all the parts of the ramps. 

 

A few questions have come up and I'd appreciate some help here-

 

1.  It appears that if I make a stepped offset from a featureline, then go back and edit the 'parent' featureline the stepped offset featurelines don't also dynamically update.  Is there a way to make the stepped offset FL's update?

 

2.  In the Elevation Editor dialog box, the 'Grade Ahead' and 'Grade Behind' columns seem different from the Profile Editor 'Grade In' and 'Grade Out' columns.  That is, for a profile PI, the columns show the grade of both the segment downstation from the PI, and the grade of the next segment upstation from the PI.  In the FL Elevation Editor, it appears the two columns show the same grade, for just the one segment upstation of the point.  Why are there two columns, or what am I missing?

 

3.  If I am drawing a new featureline and wish it to pass through the endpoints of some other featurelines and I wish the elevations of the new FL to snap to and stick to the endpoints of the other featurelines, is that possible?  Will the featurelines all stay dynamically connected?  That is, I create featurelines for the left & right sides of two adjacent ramps, at a grade of, say, 5.0%.  Now I wish to create a featureline for the landing passing along the tops of the ramps, to get the grade of the landing.  If I adjust the grades of the ramp FL's up or down, will the FL defining the landing stay linked to the ramp FL's and also adjust up or down to match?   

 

Oh yeah- C3D 2012.  Thanks.

 

Jeff Rivers

 

 


Jeffrey Rivers
Win 10 Pro 64-bit, Intel i9 3.7GHz, 64 GB
NVIDIA RTX A4000
C3D 2020 V13.2.89.0
13 REPLIES 13
Message 2 of 14
BrianHailey
in reply to: jeff_rivers


@jeff_rivers wrote:

1.  It appears that if I make a stepped offset from a featureline, then go back and edit the 'parent' featureline the stepped offset featurelines don't also dynamically update.  Is there a way to make the stepped offset FL's update?

  


No, but it's not hard to update the featurelines after editing the original. Look into using the Adjacent Elevations by Reference command.

 


@jeff_rivers wrote:

 

2.  In the Elevation Editor dialog box, the 'Grade Ahead' and 'Grade Behind' columns seem different from the Profile Editor 'Grade In' and 'Grade Out' columns.  That is, for a profile PI, the columns show the grade of both the segment downstation from the PI, and the grade of the next segment upstation from the PI.  In the FL Elevation Editor, it appears the two columns show the same grade, for just the one segment upstation of the point.  Why are there two columns, or what am I missing?

 

 


If you edit the Grade Ahead column, you will edit the elevation of the following PI. If you edit the Grade Back column, you will edit the elevation of the current PI.


@jeff_rivers wrote:

 

3.  If I am drawing a new featureline and wish it to pass through the endpoints of some other featurelines and I wish the elevations of the new FL to snap to and stick to the endpoints of the other featurelines, is that possible?  Will the featurelines all stay dynamically connected?  That is, I create featurelines for the left & right sides of two adjacent ramps, at a grade of, say, 5.0%.  Now I wish to create a featureline for the landing passing along the tops of the ramps, to get the grade of the landing.  If I adjust the grades of the ramp FL's up or down, will the FL defining the landing stay linked to the ramp FL's and also adjust up or down to match?   


When featurelines intersect each other and they are in the same site, it's impossible for them to have different elevations. This is one of the beautiful things about featurelines. Let me repeat, ANY time two featurlines cross each other and they are in the same site, they will have the same elevation at that intersection point.

If you don't want two featurelines to have the same elevation at the point where they cross, they need to be in different sites.

 

I would recommend that you study a bit on sites as it can be a bit confusing. HERE is a blog post I did on them a while back. The majority of the time when people call us for tech support with issues on their parcels, gradings, or featurelines, it's because they didn't understand the site interaction of those objects.

 

Good luck and have fun! I dig featurelines!

Brian J. Hailey, P.E.



GEI Consultants
My Civil 3D Blog

Message 3 of 14
MikeEvansUK
in reply to: jeff_rivers

I would personally go back to profiles jeff.
Offset a feature is not dynamic. The result of a graded feature can't easily be tweaked.

Feature lines and gradings are a bit unstable at times. I tend to use them gingerly or not at all. You have more control with non dynamic or just profiles & marked points.
Sorry.
Mike Evans

Civil3D 2022 English
Windows 7 Professional 64-bit
Intel(R) Core(TM) i7-3820 CPU @ 3.60GHz (8 CPUs), ~4.0GHz With 32768MB RAM, AMD FirePro V4900, Dedicated Memory: 984 MB, Shared Memory: 814 MB

Message 4 of 14
BrianHailey
in reply to: MikeEvansUK


@mikeevans wrote:
Feature lines and gradings are a bit unstable at times. I tend to use them gingerly or not at all. You have more control with non dynamic or just profiles & marked points.
Sorry.

I disagree (partially). I personally have never had any issues with featurelines being unstable as long as the person using them understands the way sites work.

 

Gradings on the other hand...

Brian J. Hailey, P.E.



GEI Consultants
My Civil 3D Blog

Message 5 of 14
troma
in reply to: jeff_rivers

You can use a grading to create a dynamically offset featureline.  Grade to distance at an elevation difference or slope. However, be careful with gradings.  As the others have said, they can be glitchy.

 

As for the Elevation Editor being different from the Profile Editor; that is a pet peeve of mine too.  There are properties of both that I like, and I wish they could both be changed to look the same with the best options of both.  For example, in the profile editor, if you edit the station of a PI, it holds it's elevation (good), but in the elevation editor the PI or elevation point will assume the current elevation of that station (bad). I also prefer the Profile Editor 'Grade In/Grade Out' as you outlined.  But the Elevation Editor includes a column listing the length of the tangent, and I miss that in the Profile Editor.


Mark Green

Working on Civil 3D in Canada

Message 6 of 14
Neilw_05
in reply to: jeff_rivers

As Brian noted, stepped offsets are not tied to the parent feature line. In fact feature lines are incapable of maintaining relationships to other featurelines aside from sharing elevations where they intersect.

 

In simple grading scenarios you might not have much difficulty manually keeping the offsets synchronized, but if the site is large or complex then it can become quite a challenge and there is greater potential for errors if you miss something.

 

Gradings and corridors are the only means we have to keep things tied together. I find corridors don't work well in site grading scenarios for various reasons so I generally can't use them.

 

That leaves gradings. They work well for curbs with adjacent sidewalks for example. Since gradings tie them all together, any edits to the edge of pavement is dynamically propagated to the curb and sidewalk. But gradings cannot produce mitered corners, so if you have mitered curbs and sidewalks you will have to do some manual work to fill in the corners, which is a lot of work and leaves you with the same problem of having to manually update everything when edits are made to the pavement. Too gradings are prone to corruption and crashing so you often end up losing work when working with them.

 

So ultimately no matter which road you take you will face some unpleasant challenges.

Neil Wilson (a.k.a. neilw)
AEC Collection/C3D 2024, LDT 2004, Power Civil v8i SS1
WIN 10 64 PRO

http://www.sec-landmgt.com
Message 7 of 14
jeff_rivers
in reply to: jeff_rivers

Thanks for the answers, everyone!  I am working through the tutorials, and navigating the help files (rather quickly, since, of course, I need to get this done on a deadline). 

 

I see now that one can set the priority of featurelines via their styles, so that the FL with the highest priority within the same site will control the elevations of lower-priority featurelines.  That is going to be very helpful. 

 

 


Jeffrey Rivers
Win 10 Pro 64-bit, Intel i9 3.7GHz, 64 GB
NVIDIA RTX A4000
C3D 2020 V13.2.89.0
Message 8 of 14
troma
in reply to: jeff_rivers

Erm...that's news to me!  I thought any featureline will edit the elevation of any other featureline on the same site at any intersection.  The controlling one is whichever one you edited most recently.


Mark Green

Working on Civil 3D in Canada

Message 9 of 14
jeff_rivers
in reply to: troma


@troma wrote:

Erm...that's news to me!  I thought any featureline will edit the elevation of any other featureline on the same site at any intersection.  The controlling one is whichever one you edited most recently.


Yes- So far I like it, but I can see this feature quickly escaping one's control if one wasn't fully aware of how C3D prioritizes featureline interactions.  The "I changed this, why did that thing change over there?" problem.

I think I'll be miles ahead if I create a couple of new styles to set the priorities of the featurelines. 

 

I see why Brian noted he digs featurelines- I've done more in the last couple hours than I ever could have the old way using alignments and profiles.  I have FG surfaces for all four quadrants of my intersection, with complete and compliant curb ramps. 


Jeffrey Rivers
Win 10 Pro 64-bit, Intel i9 3.7GHz, 64 GB
NVIDIA RTX A4000
C3D 2020 V13.2.89.0
Message 10 of 14
Neilw_05
in reply to: troma

Actually you can control update priority using Featureline Site Priority.

 

You can find info in help under the topic: Grading\Grading Properties\Featurline Site Properties

Neil Wilson (a.k.a. neilw)
AEC Collection/C3D 2024, LDT 2004, Power Civil v8i SS1
WIN 10 64 PRO

http://www.sec-landmgt.com
Message 11 of 14
troma
in reply to: Neilw_05

Well I'll be!  Sometimes I think I post just to get proved wrong.  We generally always always ensure there is an elevation point on both FLs at every crossing, so this wouldn't effect those ones I see.  But even so, it's something I should know.

 

 


Mark Green

Working on Civil 3D in Canada

Message 12 of 14
BrianHailey
in reply to: troma


@troma wrote:

Erm...that's news to me!  I thought any featureline will edit the elevation of any other featureline on the same site at any intersection.  The controlling one is whichever one you edited most recently.


This was added in a few years ago without much fanfair. I usually don't mention it in my classes or here because I recommend that WHENEVER you have two featurelines cross that you place vertices at those intersection points. It will make life SO much easier then trying to figure out that, "Now, if I edit this, will that change too? I don't remember!" situation.

 

I personally will never let two featurelines in the same site cross without a vertex on each featureline exactly at the intersection.

Brian J. Hailey, P.E.



GEI Consultants
My Civil 3D Blog

Message 13 of 14
Neilw_05
in reply to: BrianHailey

I'm with you on that Brian. It also allows you to control the elevation at that point using the Elevation tools vs. relying on interpolation.

 

If you don't want a kink in the alignment you can use elevation points, but they can be a pain if you don't get it located just right or if the alignment shifts slightly. Then you can end up with 2 elevations so close together that you can't see what is causing a bust. As I have mentioned in other posts, sometimes the Site topology rules cause more problems than they solve.

 

If we could start over I'd wish they had used a different approach, perhaps something like Bentley has done with their new civil technology where the user applies the rules as needed.

Neil Wilson (a.k.a. neilw)
AEC Collection/C3D 2024, LDT 2004, Power Civil v8i SS1
WIN 10 64 PRO

http://www.sec-landmgt.com
Message 14 of 14
Joe-Bouza
in reply to: jeff_rivers

1. If you are not queezy about using gradings; I have adopted using a Relative elevation grading off the face of curb .5 ' at a 1:1 slope and my back of urb is dynamic to the parent FL. Also, you can add trnasistion to get the drop curbs where required.

 

2. Ever since I found grade.png   I spend far less time in the elevation editor

 

3. If they are all in the same site, yes ( avoid crossing FL)

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People)

HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

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