Site Grading with Corridors in AutoCAD Civil 3D 2018: Everything Has Changed!

BRIAN LEVENDOWSKI: I am Brian Levendowski with CTC out of Minneapolis, Minnesota. This class is site grading with corridors in Civil 3D, everything has changed. Not literally, but a lot of things have changed.

My background, I'm a civil engineer, I worked in aviation design for about 10 years, did a lot of surveying. And I've been with CTC for about the last eight years. I'm a consultant to folks like you guys, and I spend my time figuring out how to make this software work. So hopefully I've got something for everyone here today.

I do want to mention one thing. The handout was not on the website, I apologize for that. I sent a message to everyone, hopefully you got it.

I made some changes to the processes here and I didn't have time to change the handout. So I will have that in the next few days. Might be in the next week, but I'll get it to everyone. It'll be a detailed handout so don't worry about taking rigorous, detailed notes. Just watch what I'm doing, understand it, and the details will come in the form of a handout.

So let's start with why, why corridors for site grading? It's more dynamic than feature lines, right? How many of us do most of our site grading with just feature lines as brake lines on a surface, right? I mean, that's the tried and true way, it's simple enough, but it's not very dynamic.

You're basically managing all these points and these slopes, and it gets to be a lot of stuff. Why corridors? They're more stable than grading objects. Grading objects are kind of cool, they can give me a daylight, they can do these different things. But then if I look at them wrong, they just disappear. So corridors are a little more stable than grading objects.

And this is some of the big stuff here, it's richer model data. I mean, when we grade sites, for the most part, we're grading the finished grade, right? Well, I care about a datum surface, I care about how many materials I have, all sorts of things like this. And so with a corridor, we have assemblies and sub assemblies, we get a lot richer data out of it.

In y corridors now for site grading, why not four years ago, five years ago? Because there's some new features in '17 and '18 that really kind of make this all possible. To me, we've just kind of hit this threshold now, where we can use corridors. And the Autodesk team has really done some work with this aim, us being able to use corridors for site grading.

So some of the old methods here, grading with only feature lines, these are some of the assumptions here, the prerequisites, is that we know how to do at least that. We know how to throw feature lines on a surface and grade in that way. Why don't we want to do that anymore? It's tedious, it's not dynamic, there's no subgrade. Feature lines and gradient objects, really buggy, no subgrade or model.

So let's understand some of these new features here. How many people are using 2018? OK, just a small, small group. How many people are using '17? OK, and '16? OK. So everyone needs to get to '18--

[LAUGHTER]

--if you want to do this stuff. So hopefully I'm your motivation to roll out '18s to your offices.

Here's a couple of the items that I'll showcase here today. Feature lines as corridor baselines. Just like this, your baseline option. And create corridor now has the feature line option. We can link feature lines to surfaces.

So in that wonderful elevation editor that we all know so well, you have a relative to surface option there. The default is absolute, where you're just managing that vertex elevation. But we can make it relative to surface.

And then there is what's called corner cleanup, or bow-tie cleanup, where we can have concentric back of curb to a flow line. Like when you ran a corridor before '18 around a 90 degree corner, it wouldn't make nice, concentric lines. It will now do this magical stuff for us. So that's a big plus.

So corridor site grading, what we're after, what we're going to do today is make this model. Using all corridors, but we're using alignments, profiles, feature lines, a number of assemblies and sub assemblies. And we're after this because, again, of all this data we can get out of it. Surfaces at multiple levels, data we can pull out of it, we can push this into Navisworks, into Revit. And it's not just a finished grade 10, it's an actual model. We can pull solids out, we can pull a variety of different things out of here.

So some of you might look at this and go, yikes, we're going to click through all of this. I'm not going to click through all of it. I've got key steps, stages I'm going to bring you guys through, through nine different drawings, kind of show you the step, the process, here's the key way to do it here. And we're going to leap from one drawing to the next.

Unless-- I mean, we can hang out for five hours if you guys want.

[LAUGHTER]

I can't, in 90 minutes, not pre-bake some things here. But the point is, I'll communicate these strategies, these workflows, and then when you kind of get it, we'll jump to the next drawing and we'll kind of run with it from there.

So the process, the workflow we're going to go through here, we're going to start with grading out our parking lot. Oftentimes that's the most complex part of a site, of a building site. That's our example here.

And what this parking lot drainage surfaces is, is to be creating a simple surface with just feature lines. We all know how to do this, throw feature lines on a surface. This concept, making this surface like this, this isn't new. But I'm using this process, this concept of a drainage surface in conjunction with corridors to give us a much more dynamic model in the end.

So all these steps here, I'm going to walk us through in the software. We're then going to create alignment and surface profiles from the drainage surface. So that surface we just made right here with these yellow feature lines, we're going to then make alignments and surface profiles cut from that surface.

So this concept stems from the idea that-- what is parking lot grading vertically? It's a fairly simple design. I just want sheet drainage this direction, like I've got swales and ridges. And it's not that complex vertically, but it tends to be complex horizontally. I've got all these little curb islands, I've got curves, and all these little things.

But vertically, it's fairly simple. So this concept is where we separate the vertical design from the horizontal design. The vertical design is accomplished through a basic surface of yellow feature lines that you see here. And we can very easily use some of the basic feature line tools to edit this and start to control the drainage pattern of our site.

And then, what is a surface profile? It slices wherever that surface is at any time, that path. So these magenta dash lines here are going to represent our flow line of our curb lines.

How many people does this concept kind of ring a bell, where you make a drainage surface or a drainage scheme surface? OK, so we're still using this. But what's going to be new is, we're going to stack corridors on all this stuff.

So we're not just doing grading objects and feature lines attached to that, we're going to put corridors on them. So with those curb alignments, they're going to attach corridors using fairly simple assemblies like this. And then we're going to target out to a series of feature lines, and we're going to introduce a second set of feature lines here.

So I've got a drainage surface made from those yellow feature lines. And then I'm going to draw other feature lines that are relative, or stuck to, or draped to the drainage surface. And that's going to allow me to basically parcel up my parking lot, my drainage pattern in ways that might vary from the actual drainage surface feature lines themselves.

We're going to use things like relative to surface, and we're going to use a feature that's been here for a long time, which is feature line style hierarchy. How many people know about this? Yeah, it's this hidden thing, it's been here a long time.

So two feature lines cross, I have to assume the same elevations if they're in the same site. And then there's this rule about like, well the last one edited is what controls it. Then you forget how it works, and it does some weird things, right?

If you assign one set of styles to one set of feature lines and another set of styles to the other set, you can control the hierarchy of those styles. Meaning the one you want to always control, put that style at the top. And then every feature line with that style will always control. So we're going to basically drape target feature lines on the drainage surface.

So this little screenshot here, this might look familiar. Maybe some guys have gone through this, graded parking lots with corridors. We could do this years ago, this has been here for a long time. It's those little things that just didn't make it worth it. In my opinion, it's the lack of these features right-- where did I go-- right here. The corners, they look like crap, right?

I couldn't link these feature lines. It became really tedious to manage all this data. And while we'll use alignments and profiles for a lot of the curb lines, we're also going to use feature lines for some things.

All right, so moving along. Next thing we'll grade, we'll have a pond adjacent to our parking lot. And we'll talk about, how do you join those two together? And I don't mean, just draw feature lines and throw them into a surface. We always want things dynamic, I want to be able to move my pond up or down, move it around, change the size of it and have it always stick to or grade to the back of the parking lot.

So we're going to define a common feature line in here that is partially relative to our existing grade, but then also something we can use to just massage the contours and the surface in that area. And we're going to look at some miscellaneous building grading here. This is going to be a separate corridor, just like the pond. And it's just to be grading around our building.

So I know every site has got some unique feature to it. I'm not going to be able to cover how to address every scenario here. But some key ideas I want you guys to take away from this, and then you can run with it from there.

All right, we are starting in this site. I've got a preliminary horizontal design here. I've got some polylines, we've got a building outline, and somewhere over here I'm going to put a pond. We're going to start with grading this parking lot, then we're going to grade the pond, and then around the building. And again, I'm going to step through some of these drawings because you guys don't want to see me click through 1,000 different screens.

So if I'm missing something, please raise your hand, interrupt me. There's a lot of stuff to go through here, so please interrupt. So first things first, we need a drainage surface. I need to dictate how this thing is going to drain. And I've cheated a little bit here, I have some polylines ready to go with this kind of stuff.

What you want to do to make a drainage surface, you want to think about how your site is going to drain overall. And you want to use a set of feature lines that's as simple as you can make it. I'm saying I've got an entrance up here, I need to drain away from here, I need to meet ADA requirements. I've got to tie into existing here, and over here. Existing grade itself falls back this way. I have all these considerations, right?

What we want to do is create feature lines from all of these. And here's where this feature line style starts to come into play. I've got a grid feature line style, and I'm going to throw it in site one. All my feature lines are going to go in that site one.

I'm a big fan of using feature lines styles with layer zero in them and then letting them use the selected entity layer. Oftentimes you might be drawing some geometry, polylines, and you just throw it on a given layer. You can let that layer continue to control, just strip the layers out your feature line styles.

I'm not going to assign elevations right now because I have some elevations on their. We want to then take these and throw them into a surface. I'm going to make a new surface here, we will call it grid.

My add breaklines dialogue box. If you guys don't know what this is, how often does it triangulate along a segment? If I've got two vertices that are 100 feet apart, how often does it 10 along those lines? If I put this at 10, it says triangles are no more than 10 feet apart. It helps you get better triangulation, better contours. This is how it triangulates along curves.

A fairly basic surface here. And what I recommend is to be using-- build some basic line or curve labels that-- let me turn on my layers here-- that label slope and spot elevations. So these are just basic line and curve labels, can build these things.

Then as you work with this, you throw these labels on here, I need to kind of roughly, preliminarily design my site. How is this thing going to drain? Well, I've got all these little callouts on here.

I can use Quick Elevation Editor. If you're not using this tool, you need to start using it. If you're stuck on Elevation Editor, that's great if you're mass editing a whole bunch of points at once. I really recommend using Quick Elevation Edit.

Because I can do things like, well, 816, yup, that's where the entrance is. Let's grade down along the face of the building at a negative 1. Make sure my surface is on rebuild automatic. And it's this really interactive way you can grade your site.

This look familiar to people, doing this kind of thing? Right. This is a really tough place to work. Point by point, don't do it here, do a Quick Elevation Edit.

So I don't want to spend a ton of time on grading this, designing this out. I have some preliminary grades in here. I'm going to move on to the next step.

One thing I want to do though, is point out, we need to tie into existing here too. So we also need to have created a few feature lines-- if I turn them on here-- right along the existing where we match in. Those are thrown into that surface as well. So I have this whole grid, this pattern that basically is the drainage pattern of my parking lot.

What we want to do from here then, is to be-- let me freeze a few of these. We need to start building our corridor. And we need to think about how this thing is going to build. So the standard rule is, we build assemblies where we have the flow line right along the alignment, or along the baseline here.

So if I go-- I've got some assemblies ready to go here and they're fairly simple. And this curb island right here, I want to run a curb around it and I want to target out from that. But I've got curb over here. If I run this and then I target this way, how do I target back?

You have to start thinking of breaking up your parking lot into panels. That's the best term I can come up for it. And this works really well with this whole feature line relative to a surface option we have.

So I've got a polyline here. OK, this would be pretty straightforward. If I take this and then I just target this thing, the lane is just going to shoot out around it. So here's where we introduce these secondary target feature lines.

So let me show how this is going to work. First we'll build-- let's call that left curb island. We're going to make a surface profile and we're going to cut from that grid surface. And I don't even need a profile view, I just need the data to slice from there.

OK, now we know that that elevation is dynamic to this. That's what we're after here. So as I continue to build out my corridor here, everything is still controlled by this. So I'm never editing the profiles in my corridor, I'm only editing these yellow feature lines.

Let's build our corridor. It's like parking lot. I'm going to build it from alignment and profile, the left curb island, and the surface profile I created there. And then the assembly, we want one with pavement on the right and curb on the left, this one right here. OK, fairly straightforward.

There's no target surface and we're going to turn off the baseline options there. Now that builds my corridor fairly simply, but now I need to take this and I need to target out to this thing right here. So let's create a feature line from this.

I'll give it a name. Feature line style hierarchy comes into play now. What if I give this the same style as those yellow ones? Now they're kind of fighting over which one controls.

I don't want to touch this feature line. All I want is for something to be something that I can target with my corridor. But its vertical elevations need to just stick to the gradient surface.

So if I set-- I've got a style in here just called targets-- and assign elevations, and elevations are going to come from the grid surface and they're going to be relative to the grid surface. That's dynamic, it sticks to the surface. So feature line hierarchy, where does that come into play?

Go to your site, you right click on the feature lines category and go to Properties. Right in here is your feature line style hierarchy. If grid is on the top, the grid feature lines will always control. This has been here for years, but to me there's never been a great place for it until some of these other new features came along.

It's got a nice 3D view here. Gonna turn off my existing as well. So all I'm after right here is to have that connect out there, simple targeting. I like to do all of this through the ribbon. Use your corridor region editing up here, edit your targets through here, and I just use the layering option.

So set this stuff up ahead of time. Understand what layers things go on. So I've got curb island left targets, it pulls that feature line in, and I want to target it for both with an offset as well as elevation and slope. OK?

One of things we're after is a dynamic model. Not just a datum surface and a full model, but I want a dynamic model. I want everything to stick to my drainage surface. That's just exactly what we've done. I've got a surface profile right here, and I've a feature line that I'm targeting that sticks to the grading surface.

So let's just make a change of sorts here. Pick this feature line, this one right here. So edit that. If we look over here in 3D, there's my target feature line, I see that just went up with it. Rebuild your corridor and the corridor updates within.

This is the basic concept here. I've got a grid surface, keep it as simple as I can, as detailed as I need for my drainage pattern. I've got target feature lines, and then I have alignments and surface profiles.

Some of you might be asking-- and this is actually why the handout isn't ready-- why don't we make a feature line for this? If I can build corridor baselines from feature lines, why don't we just make the curb island and all the other curb a feature line? Turns out, it gets really unstable when you have a feature line relative to a surface and then a corridor stuck on top of that.

It was really unstable, lots of crashing. And you get a similar thing with alignments and surface profiles, it's dynamic to the grid surface. So we're all good to go.

Can build a basic surface in here. And at this point, I'm going to turn off this surface. So we've got different areas to deal with.

I've got another area I can make a panel out of over here. So the curb islands in the middle, it works to make these panels. The panels don't necessarily have to run on your grid surface feature lines. I can make this shape anything I want.

This rectangle I drew around here for a target, it could have gone wider than this. But what happens when you do that? Well, if I target from here to a line over here, it wouldn't pick up the ridge or the swale here. So you kind of have to follow your grid lines.

But here's the kind of general rule, is draw targets wherever you need them. Make them secondary in terms of the hierarchy and just drape them to the surface. Right in the middle here, this is fairly straightforward. I've got an assembly running along this feature line right here, I target the feature line over there. Easy peasy, right?

Questions so far, is everyone with me? Is this making sense? Yeah?

AUDIENCE: In order to target the feature line that you created, does each feature line that you're targeting have to be [INAUDIBLE]?

BRIAN LEVENDOWSKI: It doesn't. I just like grabbing targets with layers. It seemed a little pointless here, but when we come down here, I'm going to have five, six targets. I don't want to go and pick them all, so I pull them in with layers.

And for some reason, the prompt to go select in drawing-- I don't know if you guys get this. Those of you who are using '18, to go select a feature line target in the drawing, is there this big delay for you?

AUDIENCE: In '17 too.

BRIAN LEVENDOWSKI: '17 too? Yeah. I thought it was just because I had a Mac or something. So for the purpose of this demonstration, I use layers.

So let's move on to one of these regions here. So I've got an alignment up here, same concept. I cut a surface profile for my drainage surface.

And now I'm going to break this up a little bit. Instead of running my lane and then targeting out from there and then having my curb on the other side, that starts to fall apart when we want to take advantage of the corner cleanup, this is the new feature in there. In order for my curb to run around this 90 degree corner, all the sub-assemblies as I understand it need to have constant widths in them in order to get a concentric corner on here.

So it's not a big deal, we'll just make two baselines. On one side I'll build the curb, on the other side I'll build the lane. So let's go ahead and turn on some line work that we're going to use for targets.

So here's my outside, my perimeter curb here. From here I'm going to be targeting this feature line. I'm going to target this. I'm coming all the way around here, targeting right along here.

And then I'm going to get in this situation where the corridor starts overlapping itself. So let's first build this, and you'll kind of see what I mean here. And we're just going to use this basic sub-assembly right here, just a simple lane sub-assembly on it.

So I'm going to pick my corridor, need to add a baseline, and it is going to be my north curb. I get a big delay right here too, just select my profile. And it's going to be that grid surface profile. So I'm adding a baseline.

How many of you guys use the ribbon here for adding baselines, adding regions? I mean, compared to corridor properties and the parameters tab, I mean, when you get a lot of stuff going in your corridor, I think it's a lot easier. Because you work region by region for the most part. This panel right here is really nice.

All right, add a region. It highlights for me. And now I can just say F for fill, which means, go the full length of it.

And I want right pavement. So zero station is here, I want the pavement on the right, hit OK. And if I ignore the targets for a moment, you'll see what we get here. And now I need to run some targets.

And here's where the layering really comes in handy, because I've got a number of feature lines that I haven't made yet. Let's create those. So these are all my target objects. Again, what do we do with these? We make them relative to the grid surface.

And I give them a style so that they're dependent on the grid surface. So assign elevations from the grid surface. You can make it relative, like it could go 1/2 a foot above. There's all kinds of ways we could be doing this.

If we didn't do the corridor, I could make my back a curb and my flow line, they could both be relative to a grid surface. If I just decided no corridors at all, but I want to do the grid surface option. Lots of ways to think about this.

All right, I've got some feature lines, they're draped again, stuck to the grid surface. I simply grab my corridor and I've got a layer setup that will grab all of those targets. You guys use this layering option?

Conditional sub-assemblies, if you guys use those. Like big projects, you could have like 20 targets. You don't want to go pick that stuff. Or maybe you get paid by the hour and you do want to do that.

[LAUGHTER]

Yes. Here's some of these extra feature lines I drew. Because what's going to happen? It's going to start crossing over itself.

The corner cleanup in 2018, kind of sort of handles this. I don't think it does a great job, and that's why I just draw some extra feature lines in here to target this and manage this area in here. You do get one odd thing where it won't target right there. And there's a setting in frequency that says, pick up my offset target geometry points.

Well as much as I can understand it, this station right here, it's closer to that point than this station is. So that functionality only works over here. I don't know, it won't pick it up. I sweared at it all day one day and it just wouldn't do it. So you go and you add the manual thing here. Not a big deal, you can do it after the fact.

So what about the outside now? I've got to put my curb around here, and I want a nice looking curb. I want a concentric corner here. And this is where one of those new features, the corner cleanup come into play.

And so what we're going to do is add a new baseline. I can't run an assembly along the same baseline, along the same station. You can't have regions just overlap each other on the same baseline. Not a big deal, at baseline it's just a reference to an alignment and profile. I still have that one single alignment and profile.

So add a baseline, it's going be the north curb. We'll call the baseline north back curb. And we're going to grab that same surface profile if it lets us.

I get this on my computer. I think it's worse on mine. This is a four-year-old MacBook, a small computer. But do other people get this, that amount of lag? OK, so not many, it's just me.

So adding a baseline-- I really think it is just my computer. I had a baseline and then I do add region. And now my little Tooltip there say, hey, you've got multiple baselines. I'll pick the north back curb, that's the one I just did.

And what I want to do, I want to fill the entire baseline. Zero station is here, I've got curb on the left. There's no targets in there so it just builds.

And here's how this works, everyone knows how to rebuild a corridor, right? It just does it. This is one of the new features that, to me, make it worthwhile to be using corridors for a number of reasons.

I need to stake this. If it doesn't give me my nice back of curb and that's what I'm staking, I've got to do a bunch of manual work for it. It looks weird. I can't sleep at night when that doesn't look like that, it's like all these key requirements.

So the rule with it though, it's a limitation. Autodesk has done some really cool programming to make this happen. You can't have other sub-assemblies in this assembly that have varying widths. So what does that mean? I can't have a daylight sub-assembly, I can't have the lane sub-assembly that I'd be targeting and varying the width. I don't know what the algorithms do. That's the ways way it works though.

But what we do have as well, this is another kind of hidden feature new to Civil 3D, I can extract a dynamic feature line from this, and then I can build a baseline on that dynamic feature line, which means it basically sticks to and it's all connected. All right, so let's do that. Pick this back of curb and I just want the back of curb point code.

Extract, and I get this dynamic feature line. Calls it an auto corridor feature line. And so we'll name this thing North Back. I can add a baseline, it'll be a feature line, and it will be the north back feature line.

One thing to note here, I don't have in a site. This is a new feature as well, you can have feature lines not in a site. I don't want this thing interacting with my grid surfaces at all. This thing is attached to my corridor, I want it to stick at back of curb. It's just along for the ride with my flowline alignment and profile. So leave that outside of a site.

So I've got that baseline, now I do Add a Region. I'm going to fill the whole region, and I've got left daylight. Brings up my corridor mapping, EG, and it daylights.

Does it round the corners really nicely like grading objects? No, it doesn't. You can get crazy with it and do some targeting. But I can sleep at night with this, I'm good with that.

AUDIENCE: I've got a quick question.

BRIAN LEVENDOWSKI: Yeah, go ahead.

AUDIENCE: Is this all part of the same corridor?

BRIAN LEVENDOWSKI: So far it is, yeah.

AUDIENCE: You can have more than one baseline in a corridor?

BRIAN LEVENDOWSKI: Absolutely. You should have more than one baseline in a corridor, yeah. You know, as a general rule, parking lot sites, roadways, whatever, I like to put as much as I can in one corridor until it's too much in one drawing, it just slows down or is too much to manage. A number of reasons, but one of the main reasons is the corridor surface.

Like an intersection, there's so much going on in there. If you have that all in one corridor, your corridor surface, it's just one surface and it just does it for you. When I think of corridor surfaces, I don't really want to be touching those things. If my corridor isn't generating my surface properly, I'm not building my corridor properly.

The focus is on the source object, the corridor. So my rule for when I break a corridor, say there's a gap between my project, and I've got a road project and there's a bridge I'm connecting, an existing bridge, I'd separate those. Because the surface boundary thing falls apart when you have gaps between your regions. And then separate it when it's just too big, there's too much in one drawing, you could put it in another drawing for example. Other questions? Yeah?

AUDIENCE: Is there any advantage to doing the two separate baselines for one for the daylight, one for the curb assembly rather than making daylight the target first?

BRIAN LEVENDOWSKI: Yeah, yeah. So the question is, is there an advantage to doing the two separate baselines? And I assume you're talking about right here at the flowline where on one side we had the pavement and on the other side we had the curb?

AUDIENCE: No, [INAUDIBLE]

BRIAN LEVENDOWSKI: Or right up here?

AUDIENCE: --one for the daylight and one for the curb.

BRIAN LEVENDOWSKI: Yeah. So the same rule applies here. Why did we make a separate baseline here and why didn't we just put the daylight sub-assembly on the curb?

AUDIENCE: Right.

BRIAN LEVENDOWSKI: The curb won't do this. If I have-- so that's the rule, the little limitation, is that it won't do this thing, make a concentric corner if I have a varying width sub-assembly in my corridor region.

AUDIENCE: OK.

AUDIENCE: So you put the same environment in as two baselines--

BRIAN LEVENDOWSKI: Yeah.

AUDIENCE: --and just renamed the baseline?

BRIAN LEVENDOWSKI: I just gave it a different name. It would have given it a different name anyway. But yeah, you can have infinite number of baselines in your corridor with the same alignments and profiles.

It's not a good practice in a conventional corridor. But in this case, we want to take advantage of this corner cleanup thing so I got to jump through the hoops and make the second baseline. It's worth it though, because it's all coming from the same source. I'm not duplicating stuff, I don't have all this redundant stuff. Everything here is still stuck to the gradient surface.

Other questions? We'll move on if there aren't. Yeah?

AUDIENCE: You said that you would [INAUDIBLE] into different drawings if it got to [INAUDIBLE] just driving me nuts. So would you utilize your data shortcuts, and can you connect those two surfaces together?

BRIAN LEVENDOWSKI: Yeah. So the question is, you've got a big site, a big project, how do you break it up into multiple drawings and then bring that stuff back together? You can data shortcut in newer versions of Civil 3D, your corridor. So multiple corridors can go anywhere. If you're after a composite finished grade surface, data shortcut those surfaces and make a composite overall finish grade or datum surfacer, any number of them.

It's not great. Like, I wish we could just put an entire city in a drawing. But it won't handle it. But yeah, corridors, they are in 2018. I think that was '17. Yeah, they came out in '17. You can data shortcut them now.

All right, let's move along. This region down here, this is pretty similar now, right? I can run this along here, I can target along here. So I've got a set of targets along the south end. These green ones right here, these are my target feature lines, they drape to the grid surface, and I just target.

The hardest part of this process is not putting your targets on layers. It's not, remember to build the second baseline. It's, look at your site and come up with a plan. Because everyone's looking at this going, I never did a parking lot like that, mine always have the thing with the deal and the-- right? It's being creative and figuring out how you're going to build this corridor for your parking lot that sticks to your grid surface. That's the challenge, that's the hard part.

So this builds in a similar way. We're going to jump to-- look at that, it's done.

[LAUGHTER]

I built this in the same, same way as this way here. These areas where I've got inside 90s, I put a feature line there and I target. Again, you can do some of this with the bowtie cleanup. Let's actually do it right here. We're going to experiment.

That's what would happen, right? That looks like crap. There's clear corridor bowties. This mostly is great and like a curb return area where the daylight lines are crossing over each other. It can work here and there in this situation.

And so you have to tell it, specify a baseline. Well, I'm looking right here. Specify the starting subentity, that's right there, the ending subentity right there. Where I want to clean this thing up, well, it's basically right in here. Let's see if it does it.

What it does is it makes the sub-assemblies project at non-perpendicular direction.

[LAUGHTER]

See why I say to use the feature lines?

[LAUGHTER]

I shouldn't have done it. OK, it works sometimes. Mondays and Fridays, but nothing in the middle of the week. Luckily we have this feature here, Task Manager.

[LAUGHTER]

It allows us to wake up Civl 3D. You guys know about that one?

[LAUGHTER]

It's new in 2018 and you only get it if you buy the productivity pack add-on.

[LAUGHTER]

I think we left off about here. Any questions while I'm loading some of these drawings again? Yeah?

AUDIENCE: You mentioned earlier, there's only one corridor. So to clarify, the corridor with the little island and the [INAUDIBLE]

BRIAN LEVENDOWSKI: Yeah. The question is, I said, only use one corridor. Yes, only use one corridor so that we can just turn on our surface and it triangulates everywhere. This is all one corridor, it's multiple baselines. That's the distinction here.

A corridor is not a single alignment and profile. In fact, a corridor of any complexity, you've got to be moving to multiple baselines.

AUDIENCE: Quick question.

BRIAN LEVENDOWSKI: Yeah?

AUDIENCE: The only downside of having everything in one corridor is, if you had a dynamic feature line created and it's targeted within another baseline in there, [INAUDIBLE] confused.

BRIAN LEVENDOWSKI: Yeah.

AUDIENCE: And that's the only downside. That's why I try not to. Is that different for 2018?

BRIAN LEVENDOWSKI: Yeah. So the question is, if you have everything in one corridor-- I'm not sure I fully understood it. Like, you can create some continuous loops, right? Depending on what you're targeting, yeah.

I mean, if I targeted those yellow feature lines and those yellow feature lines were making the grid surface, then my alignment and profile were based on the grid surface then I built a corridor on that alignment and profile, that's the circular loop. Yeah. I tried this a lot of different ways where I was targeting these yellow feature lines and it got really unstable, and I think it was for that reason. Is that what you're talking about, or was there something else?

AUDIENCE: It's like when you do a corridor and you create a dynamic feature line into that corridor, and then you have another baseline that comes in that's targeting that dynamic feature line, that's when it doesn't work [INAUDIBLE].

BRIAN LEVENDOWSKI: Right, right, OK. So he was bringing up the situation-- If I had a dynamic feature line like we created here, and then I had another baseline, whatever the project might be, and I targeted that all within the same corridor, yeah, that gets unstable. So that's another reason for a second corridor, you kind of have a primary and a secondary. I do this with a large intersection where it just doesn't make sense to do it all in one corridor.

You've got a primary road, and then along those edges of travel way or something you target that dynamic feature line from the side roads that are coming up to it. All right, let's move along here. We have a similar situation that we've created over here. But I'm not going to do just the daylight here, because I've got ponds, and I've got a building to tie into, and a variety of things here.

So let's look at grading this pond. That's what every pond looks like, right? I'm not going to get into detailed pond grading here. You can do this with all kinds of benches and everything. My point here is to show you how to deal with a corridor and how to have it tie in dynamically to a parking lot next to it.

Let's make a feature line out of this. So alignment and profile, I'm not going to bother with this. This isn't a grid surface scenario. The grid surfaces is-- it's all about parking lots, because we can separate the vertical design from the horizontal design.

A pond, I don't think we need to do that. I can define some baseline or multiple baselines and I can start targeting and building regions and assemblies on those. And that's what I'm going to do here.

I've got an assembly over here I'm going to use. This is going to be my baseline. And this will be the inside of the pond. And I've just got it set so it's just going to meet right in the center there. But we could do all kinds of targeting, and benches, and all kinds of things. That's fairly straightforward corridor modeling.

Then on the outside, what I want to do, I want daylight out here to existing, and then I want it to just magically connect to my parking lot. We're going to introduce some more line work here. I'm going to use that in a second.

First thing, I'm just going to build my corridor. And I'm going to make a second corridor here. It could go in one, this is kind of take your pick. But I'm going to do a second one just because I can.

And we're going to do a feature line, and we're going to do-- let me name this thing. Feature line from base line. There's my pond feature line.

The assembly is going to be this one over here, the pond assembly. The target surfaces is going to be existing grade. I'm not going to bother with my baseline and region parameters, it's just going to go around the whole baseline. So I hit OK and there it is.

Now how do I make this dynamic? I can put a feature line in here and I can just have each corridor targeted, which is what we're going to do, but I want it to be more dynamic. I don't want to have to build one region where it targets this, and another region where it daylights, right? I want it to just know when it's supposed to match in and know when it's supposed to just daylight. So I want to either target this or match into existing.

Enter conditional sub-assemblies. Conditionals work based on targets. How many people know conditional sub-assemblies? So less than half the room, so let me explain them a little bit.

Conditional sub-assemblies don't build anything in your corridor. They're basically used as a pair. They're like an if statement in your corridor. If I find a target, do this thing, meaning what else is connected to me. If I don't find the target, do the other thing.