Topic: [C3D] Modeling a cul-de-sac with islands

[Guest]

I've looked at some of the cul-de-sac tutorials and we have the Mastering C3D 2008 book, but this one is giving us a bit of a headache (simply because it's not "perfect" like the examples).

What's the best way to approach modeling this? (see image)  And how should I handle the islands?  I was thinking feature line grading?!?



*sits back and waits for the gurus to chime in*

[mjfarrell]

For the island create your alignments and profiles
One should model the basic part of the culdesac first, and create the surface for it.
Then create your profile views for the island alignments
and be sure to sample the corridor surface such that you can use that as a base design for your island proposed grades (tangents) by snappy to, or using that corridor surface as a reference to guide the island profile design.
Then put a curb assembly around the island.
Add a new baseline to your corridor for each island alignment (note do not let them overlap, 0.01 is close enough for the model to work.

Or you could limp along with feature lines on top of your corridor, but why?

[KW-EGA]

I would suggest just using feature lines for bulb part and islands or the entire model. While it might not be the "flashiest" way to do it, using feature lines will be the quickest and easiest.

[mjfarrell]

I would suggest just using feature lines for bulb part and islands or the entire model. While it might not be the "flashiest" way to do it, using feature lines will be the quickest and easiest.

KW, in the long run the quickest and easiest way will be for the user asking how to do this is to learn to do this as part of the corridor model.

The bulb is really quite easy with an assembly that follows the face of curb, or back of curb alignment, and the pavement section transitioning to the CL alignment and profile. Some users find this easiest to do as one continuous alignment around the bulb. Others use a left and rt alignment with two different assemblies. This allows the user to adjust the profile of the curb and centerline quite rapidly to refine the design later.


"NOTE: Edited to remove ambiguous pronoun, so as not to appear to be casting aspersions on any one."

[Maverick®]

*sits back and waits for the gurus to chime in*

Dood!  That totally looks like a leaf blower.

[Guest]

*sits back and waits for the gurus to chime in*

Dood!  That totally looks like a leaf blower.

You flip it around and it kinda looks like a pe...

It is, after all, a cul-de-sac!

[dfarris75]

 

[dfarris75]

Stand it up and maybe a golf club?

[Maverick®]

  

It's one of those days isn't it? 

[KW-EGA]

I would suggest just using feature lines for bulb part and islands or the entire model. While it might not be the "flashiest" way to do it, using feature lines will be the quickest and easiest.

KW, in the long run the quickest and easiest way will be to learn to do this as part of the corridor model.

The bulb is really quite easy with an assembly that follows the face of curb, or back of curb alignment, and the pavement section transitioning to the CL alignment and profile. Some users find this easiest to do as one continuous alignment around the bulb. Others use a left and rt alignment with two different assemblies. This allows the user to adjust the profile of the curb and centerline quite rapidly to refine the design later.

I still disagree with you. I would have the site modeled with feature lines before you finished building your assembly. You would need nearly as many (if not more) alignments for this particular site as you would feature lines.  I have modeled a sudivision with 5 or 6 cul-de-sacs with only a corridor and I didn't really see the benefit of it. The only time I see using a corridor for a site like this is if you need to model a vertical curve.

[dgreble]

I would suggest just using feature lines for bulb part and islands or the entire model. While it might not be the "flashiest" way to do it, using feature lines will be the quickest and easiest.

KW, in the long run the quickest and easiest way will be to learn to do this as part of the corridor model.

The bulb is really quite easy with an assembly that follows the face of curb, or back of curb alignment, and the pavement section transitioning to the CL alignment and profile. Some users find this easiest to do as one continuous alignment around the bulb. Others use a left and rt alignment with two different assemblies. This allows the user to adjust the profile of the curb and centerline quite rapidly to refine the design later.

And what makes you think he doesn't know how to model this with a corridor?

[mjfarrell]

I would suggest just using feature lines for bulb part and islands or the entire model. While it might not be the "flashiest" way to do it, using feature lines will be the quickest and easiest.

KW, in the long run the quickest and easiest way will be to learn to do this as part of the corridor model.

The bulb is really quite easy with an assembly that follows the face of curb, or back of curb alignment, and the pavement section transitioning to the CL alignment and profile. Some users find this easiest to do as one continuous alignment around the bulb. Others use a left and rt alignment with two different assemblies. This allows the user to adjust the profile of the curb and centerline quite rapidly to refine the design later.

And what makes you think he doesn't know how to model this with a corridor?

If by HE we are referring to the poster asking how to model the cul de sac as part of a corridor, or use feature lines. The HE, I was using the personal pronoun for was the user named Matt W. And from his question it appeared that he could not do this as a corridor. So with the He being MATT W, not the HE being KW-EGA, are WE OK with that assessment?

[mjfarrell]

Can I have a Drawing of the basic geometry?

I'd like to rip a couple of assemblies off of my tool palette and see how they fly.

[Guest]

Can I have a Drawing of the basic geometry?

I'd like to rip a couple of assemblies off of my tool palette and see how they fly.

Yeah... I'll post something in a few....

So, I'm thinking about making an alignment for the oval portion with additional alignments for the curbs/walks around the oval and shooting the corridor out to those alignments so they follow it nicely.  Then for the main drive, make another alignment and do the same for the curbs/walks there as well.  As for the two small islands, I was planning on using feature lines.  Does that sound like the right approach.


Sure, I could fumble my way through it using feature lines, but in the long run I want to do it/learn the better way (in my opinion) using cooridors.  Not only am I creating the contours, but with the corridor and the various rendering materials attached to it I plan to also add the finishing touches to this image...   


I suppose you'll also want some existing grades around the roadway as well?  Let me know.

[Guest]

Here's the basic roadway geometry.



So I'm struggling with 1) creating a surface from 2) alignments that can also be used to build this cul-de-sac/roadway.  Ideally, I'd like to be able to through in one or two alignments that would also double as a site layout/dimensional layout item.  Add a few line/curve tables and have something that someone can stake out and build off of.  Right now I've got two alignments (one for the loop and one for the road) and they don't "line up" and I would have to add more notes/dimensions to the drawing just so they can locate the alignments and build this.  Maybe I'm not thinking clearly because my mind is elsewhere at the moment.   


Here's a piccy!  Maybe I should just wrap the main roadway alignment around the loop and make it one continuous alignment?  That would make it easier to stake out and build off of (I think).