topic Re: Broken Sample Line View at Station 7.5 in Civil 3D Forum

Broken Sample Line View at Station 7.5

soonhui — Tue, 15 Apr 2025 02:56:32 GMT

Here's a drawing, I wish to draw your attention to Sample Line 7.5 for J1-Left Curb Return Alignments

I've plotted out the section view, and this is what I got:

Out of so many stations, only this station at 7.5 has this distorted sample view. The rest looks OK.

Why this is so? I have carefully constructed the Corridor regions so that they won't overlap in practice. Any ideas will be greatly appreciated. I've also attached the drawing here.

Re: Broken Sample Line View at Station 7.5

nkiakas — Thu, 17 Apr 2025 12:48:14 GMT

Hi @soonhui

You have targeting problems in the junction.

Check the offset + elevation targets of the 2 red highlighted baselines of your corridor

Regards

Re: Broken Sample Line View at Station 7.5

Ragdern — Fri, 18 Apr 2025 00:05:47 GMT

As @nkiakas has said you have targeting issues. There are also overlapping segments. Depending on how you fix these issues using radial sections can give distorted grades in areas.

Re: Broken Sample Line View at Station 7.5

soonhui — Fri, 18 Apr 2025 01:04:50 GMT

@nkiakas , it's not immediately clear from your snapshot exactly what is wrong with the targets at the connected alignment-- the offset and elevation looks alright to me.

@Ragdern , what overlapping segments? It's not immediately clear from the snapshot that @nkiakas attached. Can you be more specific?

Re: Broken Sample Line View at Station 7.5

nkiakas — Fri, 18 Apr 2025 08:43:52 GMT

Hi @soonhui

Your corridor has several Baselines with regions.

At least two of your regions are overlapping (they are one above other).

Take a look in the snapshot. The area with the white question mark is a common (overlapping area) of the yellow and green regions.

This is not correct.

You have two options. First. Keep the green region and change the assembly of the yellow region and use assembly with one only lane. Second. Keep the yellow, adjust the start/end of green region and change the offset + elevation targets of the green region.

After finishing the above, and you see something weird, focus again in the offset + elevation targets.

Regards

Re: Broken Sample Line View at Station 7.5

soonhui — Fri, 18 Apr 2025 09:21:48 GMT

@nkiakas , I'm aware of that but I don't think that's a problem, because even though the region "appears" to be overlapping, but at the overlapping area, there is only one set of assembly being defined (ie: only the assembly from green region is being applied there, and the assembly from yellow region-- the right side of the road1-- is purposefully not defined) and hence, it should have no overlapped at all in practice.

You may look at how I do my Target Region to verify what I say.

Re: Broken Sample Line View at Station 7.5

nkiakas — Fri, 18 Apr 2025 18:29:48 GMT

Hi @soonhui

See the section i created in the station 708.76

You both overlapping and targeting problems.

The red highlighted is the overlapping problem and the red question mark is the targeting problem.

The proper way to fix it, is to start from the redefinition of the involved regions and then check again (and again as @Joe-Bouza says) the offset + elevation targets

Regards

Re: Broken Sample Line View at Station 7.5

Ragdern — Sat, 19 Apr 2025 22:45:46 GMT

@soonhui See attached images. Even though you say you don't have the assembly defined where @nkiakas indicates overlap, it still generates the subassembly and is included in corridor and surface generation. The corridor is simply set up incorrectly. Another issue you have is the offset alignment profiles being used for the curb return profile definition has the incorrect offset slope (positive instead of negative) in areas.

Additional concerns:

The 2.4% offset profile to account for the 0% drainage feature added to the sides throws off the connection where the 2.5% pavement ends (not a huge issue for most things).

Where the radial assemblies meet the intersection of Road1 and Road2 there isn't a radial connection at the intersection point. This is minor but it can throw off the surface if a plan surface label is necessary.

Re: Broken Sample Line View at Station 7.5

teerawat.pSCHYQ — Mon, 21 Apr 2025 02:20:45 GMT

Hi @soonhui , I am surprise that you create sample line along Curb Retune Alignment.

and look like your corridor are overlapping at junction, such as you already apply full section at junction like this

then for right and left curb return, you should set target to these line like this

Re: Broken Sample Line View at Station 7.5

soonhui — Mon, 21 Apr 2025 06:43:19 GMT

I guess I know what's going on now. For the overlapping region ( yellow region below),

I meant to define only the Left Hand Side ( so that the right hand side is empty for the intersection regions to fill in). However the way I did it wasn't correct-- I didn't define the Corridor transition for those stations( 690++ to 721 ++). But that's not the correct way, even if I didn't define the corridor transition, there will still be region defined by having the region taking the default values of the applied assembly(ies).

The correct way of doing it is either like @teerawat.pSCHYQ said, or to have different assembly definition on the left and right hand side. The later option is so that we can still leave a gap at the RHS for the intersection region to take hold.

But keep in mind that once you reach the end of the alignment for a baseline region, you can't define anymore region already. So the way to do it is that we need to really split it into multiple regions ( region(s) with only left assembly applied, region(s) with only right assembly applied, and region(s) with both assembly applied). Doing this will avoid any of the region overlapping.

Currently in my drawing there is only one type of region: assembly with both left and right, which gives rise to the overlapping issue.