Intersecting roads

bntheman · 24 Sept 2012, 17:00

okay,
so i decided to use the shapebend tool, since it was giving better results. Howver, how can I intersect these 2 roads? also, please ignore the blue line. It's Sketchup's blue axis.

here is example

Dave R · 24 Sept 2012, 17:23

Your image doesn't really give much to go on. And it doesn't show up in the thread, either.

Assuming you've used Shape Bender on both roads they're components. You can use Intersect With Model to cut one to fit the other. Keep in mind that faces that are coplanar won't get intersected so you'll have to manually draw in the lines on the top and bottom. Just remember to open the component for editing before you draw the lines or do the intersect.

bntheman · 25 Sept 2012, 04:18

@dave r said:

Your image doesn't really give much to go on. And it doesn't show up in the thread, either.

Sorry about that.

Also, I will not be able to simply use the the intersect feature, because there is a huge slope difference and my curbs are drawn out as well. I will post better pictures. I hope this clarifies things up. Please let me know...

Dave R · 25 Sept 2012, 09:09

Think about it. If these were real roads, would they meet this way? I doubt it. Something has to happen to at least one of the roads to prevent that valley. Maybe the narrow road levels off for a stretch as it crosses the wide road? How would real curbs make the transition around the corners? Draw that.

If I had to drive down that road and hit the valley you've got drawn I would think ill things about the "rocket scientist" who designed it.

bntheman · 25 Sept 2012, 13:01

Dave, not one thing you said made sense in helping to resolve my issue.

@dave r said:

Think about it. If these were real roads, would they meet this way? I doubt it. Something has to happen to at least one of the roads to prevent that valley.

that is my question. Is there something or some tool that could fix this valley? Or, how could I have prevent it after I had drapped my line over a hilly terrain and before using the shapebend plugin?

Dave R · 25 Sept 2012, 13:19

You've shown nothing but these "roads." Where is the terrain? If it has the same sharp valley, you should smooth that out. If it was real you'd push some fill into it or you'd cut down the surrounding area or both. Draw that.

You could use the Sandbox tools to project or stamp the roads on your terrain. Draw them in 2D above the terrain and drape them onto it. Check out the Help files on the Sandbox Tools for a good start on using them.

TIG · 25 Sept 2012, 14:05

Seems to me the ShapeBender tool isn't [as fine as it is] the tool of choice in this situation.
You want to make two roads at different gradients meet nicely - just like they would if properly engineered and constructed in the real world.
A road doesn't slavishly follow the terrain but has sweetly swept gradients and bends to ensure it works safely...
The Sandbox Drape of a road layout will not get you what you want and it's just lines onto a surface.
The Sandbox Stamp tool, which will make cuttings and embankments, is more like you need...
However you first need to construct a realistic road surface to 'stamp'.
I suggest you might forget about the curbs and add those later - just how realistic does this need to get ?
My ExtrudeEdges... tools and Fredo's CurviLoft tools will probably be best to make swept surface between some curves that you weld up to form road perimeters and cross-sections...
the Sandbox from Contours might also work?

bntheman · 28 Sept 2012, 14:28

@tig said:

Seems to me the ShapeBender tool isn't [as fine as it is] the tool of choice in this situation.
You want to make two roads at different gradients meet nicely - just like they would if properly engineered and constructed in the real world.
A road doesn't slavishly follow the terrain but has sweetly swept gradients and bends to ensure it works safely...
The Sandbox Drape of a road layout will not get you what you want and it's just lines onto a surface.
The Sandbox Stamp tool, which will make cuttings and embankments, is more like you need...
However you first need to construct a realistic road surface to 'stamp'.
I suggest you might forget about the curbs and add those later - just how realistic does this need to get ?
My ExtrudeEdges... tools and Fredo's CurviLoft tools will probably be best to make swept surface between some curves that you weld up to form road perimeters and cross-sections...[attachment=0:38eyhf0e]Capture.PNG[/attachment:38eyhf0e]

Hi Tig,
I am sorry that I took so long to respond back, but I was trying to play with the different tools that you have mentioned. I was a little confused with your explaination, but one thing I do agree on and understand, is that it is much easier to create the road surface on the terrain and worry about the curbs latter. I guess the biggest problem I have is wondering if in real life the left and right sides of the streets are perfectly parallel to each other. If I picture it in my head, this is what I have came upon.

Starting with if the both sides of a road are not parallel to each other, then the road can get severly lopsided in areas. An example of this case would be, one side you see houses sitting on hills and the other side is more flat. This also applies to roads that intersect. On the other hand, if both sides the road are constructed to be parallel, this seems to solve the lopsided issue but then it can cause problems with intersected roads, like the above pictures.

You have drawn an example, but it still does not clearly show how you did it, step by step. If by all means, could you elaberate on this a bit more? I would greatly appreciate it.

bntheman · 2 Oct 2012, 01:30

Tig and others,
did I say something wrong? I do not think it was wrong to ask if it can be explained in a bit easier way. Please remember, although maybe this topic is a bit more advaanced, I am still a newbie to Sketchup. Also, did forget to mention how percise this needs to be. Being this would be for a video game that I would like to develope, my goal is to have enough detail for the player to walk on. Therefore, I need this just enough so that curbs and the street are defined but yet low enough poly for a video game.

TIG · 2 Oct 2012, 09:10

Have you tried drawing the edges of the road as lines/curves in 3d and using any of the tools I suggested?

The native Sandbox from Contours tool might 'skin' a set of edges for you.

You cannot simple draw two straight pieces of road that crash into each other and expect a magic tool to sort out the 'transitions' needed.
Look at some roads in the real world to see how a sloping side-road changes as it approaches the main-road... It will change its gradients etc; as well as the curb-lines sweeping at a radius to allow vehicles to turn easily...

Here's another 'simplistic' way.
Let's assume the main-road is flat and the side-road slopes down onto it.
Draw your road layout 'flat'.
Keep the side-road 'axial' in plan - the main-road's plan-angle is unimportant.
Close the ends so that a single face forms
PushPull it up into a 3d road-block.
Group that.
In 'elevation' draw a long-section though the side-road, with sensible transitions as it meets the main-road.
If you draw it on the side of the PushPulled block its edges will stay coplanar
Draw a straight 'diagonal' to close the loop and make a face.
PushPull that sideways fully through the road-block.
Select-all of its geometry.
Edit>Cut to the clipboard.
Edit the road-block.
Edit>Paste in Place
Select-all.
Context-menu > Intersect with Selection.
Lines appear where the parts intersect.
Erase the unwanted parts.
Tidy up face orientation so all road surfaces are the front material.

bntheman · 2 Oct 2012, 15:35

@tig said:

Have you tried drawing the edges of the road as lines/curves in 3d and using any of the tools I suggested?

The native Sandbox from Contours tool might 'skin' a set of edges for you.

You cannot simple draw two straight pieces of road that crash into each other and expect a magic tool to sort out the 'transitions' needed.

Okay now I see why you did not understand why I could not get jist of it. The sentance: "Have you tried drawing the edges of the road as lines or curves in 3D and using any of the tools I suggested?" shows that I did not clearly specifiy that in my previous post. To think, all of the things you had told me to do with the sandbox tools, I was doing but did not mention that, but instead I was using the sandbox tools by picking one road at a time instead of using the whole map. Therefore when I stamped an intersected road on top of a previous stampped area, it would not come out as a smooth transition between the 2 intersections. Sadly, that it took this many post, when technically I should of just asked how could I make my flat road map follow the contour of my terrain.

I will try this out and get back to you if I have anymore problems, and thanks agian.