I’ve had students ask me how to correctly tie in their contour lines when they’re creating a corridor. The main problem that they’re having with the software is the fact that it daylights very well – it grades based off of your criteria, and when it hits daylight, it stops. In theory, this sounds very good – hey, the software is doing what we want it to do, right? But in the real world, engineers will try to drag that contour out so it doesn’t create an angle, but it creates a very nicely rounded daylighting. Until a few weeks ago, I wasn’t even sure you could do this automatically. To be honest, I’m still not.

What I’ve got is a very nice corridor model with very ugly contours (at least where they daylight, or tie in.) You can see below:

Now, where those contours daylighted, I’d likely make some “swoops” (as a previous project manager used to say…) to make the contours tie in more naturally. I thought that there was no good way to do this using the subassembly properties, until Peter Funk mentioned something in the Autodesk discussion group about rounding. And once I looked into it, I was convinced. I just haven’t had time to play with it enough to perfect it.

First, we have to look at where to set these options. Rounding is set in the Advanced Properties of the subassembly. You can see the various options here in the DaylightMultiIntercept subassembly:

You can see here that I can select a few options here. I can select how to round the tie – by radius or by length. Also, I can specify the rounding option – Parabolic, Circular, or None (none turns off rounding). Next, I need to specify the rounding tesselation. Higher numbers make for more vertices, which (in theory) makes for a more smooth rounding. The last option to set is the rounding parameter – this is a number that will serve as either the length or the radius of the rounding, depending on what Rounding By and Rounding Option that I pick.

Well, in playing with it, I first tried a bit of parabolic rounding. I figured that would look good, so here is the same area that was shown above, only with a parabolic rounding applied:

Well, that looks terrible. There’s some little jaggies in there that I don’t like, and it just doesn’t look good in general. Let’s try a radius –

Better, but still not perfect. One thing that seems to be throwing a kink into the works is the surface boundary that I specified in the corridor properties. However, this is a bit of a necessity in the case of my road here…

It’s still not up to my specs, but your mileage may vary. I’d suggest playing with the settings to get your desired results. If you get it working correctly, feel free to email me a screen grab – I’ll be glad to post it here, along with some publicity for you and your firm. Let me know the settings that you used to get the desired results.

Have Fun!