Modelling complex road networks

[Paul King]

Hi, I want to find a way to put a camber in a complex roading network, with radiused road intersections, variations in road width etc as you move along (i.e. a strictly linear/extruded solution wont work)

Basically I need to start with a slab, that follows the road edge boundaries, and bulge it upwards between the edges

Essentially, imagine a piece of Swiss cheese, with a slab defining the outside edges and holes in the middle, and now attempt to smoothly bulge upwards between the slab edges and holes.

Attempting to do this via contours on a mesh is prohibitively time consuming (and it crashes my machine after a while).

What do others do to emulate lofting or bulging in non linear perforated elements ?

[Paul King]

Nuge wrote:
if you are using octane render why dont you create a displacement map and apply it to the meshes (use a gradient to get the curve looking right)

Nuge

That is a very interesting idea! Could certainly save a lot of memory.
But would I then need a displacement map the size of several city blocks to deal with all the specific irregularities in the road widths ,transitions, radii etc? How big can a texture be in Octane ? i.e am I correct in assuming a single linear segment of gradient as an alpha map would only work for linear roads? Would I have issues with cars etc being embedded in road surface?

Cheers

[Nuge]

Paul,

you would need 1 map to cover the area you are working in (you could have several maps that you change out for each camera if that works), I think octane can handle 31,000x31,000 but some one else may be able to confirm this figure.

The car issue could be a killer as yes your cars would protude into the displaced mesh (you will have to manually match each car the the displaced mesh)

you will need to build the map in photoshop and make the necessary changes to match your road widths etc

[Eduardo Rolon]

With a little effort I was able to do this using complex profiles and morphs. Is it close enough?
• For an intersection you will need to split the road at logical points that you can control. To create the camber on the road on the curve you will need to do some extra steps but they are not that difficult.
• BTW AC is not made to do this…

[Eduardo Rolon]

another shot

[Eduardo Rolon]

Elevation

[Paul King]

ejrolon wrote:
With a little effort I was able to do this using complex profiles and morphs. Is it close enough?
• For an intersection you will need to split the road at logical points that you can control. To create the camber on the road on the curve you will need to do some extra steps but they are not that difficult.
• BTW AC is not made to do this…

Thanks for that Erjrolon.

This far I have got with my own experiments with morphs and complex profiles, but it was the radiused 3 way and 4 way intersections , and the smooth changes in width that stumped me.

Another idea was to make a mesh, apply a single raised contour to a polyline running down the centre (which I easily adjust to deal with changing road shape), and use morph smooth faces command to give curvature - but no luck.

I looked into the sketchup option too, but I note that at least one explicitly says it can only handle parallel sided roads

[Eduardo Rolon]

I know that straight change in width can be accomplished with the Shell tool using the Ruled Surface Option. So you might explore on how to model the two streets But a 4 way curved intersection will require a lot of planning on how to build the individual segments. In one case I did a combination of Morphs and Meshes to achieve some of the transitions.

• So my workflow for this would be:
1. Define specific ridges on the streets and simplify the ridges as much as possible.
2. Draw the Ridge using the Morph tool to have points to snap to.
3. Used ruled surfaces for sections that change width or merge
4. Use Complex Profiles converted to Morphs for simple curves or straight elements that elevate.
5. Use Complex Profiles applied to Beams or Walls for straight sections.
6. For the Big intersections then I would try a mesh.

----
But still AC is not a good tool for this

[Paul King]

ejrolon wrote:
I know that straight change in width can be accomplished with the Shell tool using the Ruled Surface Option. So you might explore on how to model the two streets But a 4 way curved intersection will require a lot of planning on how to build the individual segments. In one case I did a combination of Morphs and Meshes to achieve some of the transitions.

• So my workflow for this would be:
1. Define specific ridges on the streets and simplify the ridges as much as possible.
2. Draw the Ridge using the Morph tool to have points to snap to.
3. Used ruled surfaces for sections that change width or merge
4. Use Complex Profiles converted to Morphs for simple curves or straight elements that elevate.
5. Use Complex Profiles applied to Beams or Walls for straight sections.
6. For the Big intersections then I would try a mesh.

----
But still AC is not a good tool for this

Hi thanks again Ejrolon. - the trick is that there are no straight changes in width - all follow curves.. and trying to join a morph to a mesh without visible seams will be a nightmare...
I was really hoping for a simple lofting technique.
If I am doing the intersections and other complicated parts with mesh anyway, then I might as well do everything with mesh, as the straight parts are just linking straight across between the two complex ends- no nodes in the middle really need extra definition

I know Morph already has a single point bulge tool - I just need a way to consistently extend this bulge along the middle of roads

A couple of examples attached

*** EDIT - the forum wont allow more than one it seems

[Paul King]

... and the second image

[Eduardo Rolon]

Without having all the information, this is an example using Meshes and Morphs. It is not pretty and I am convinced that if we had specific Civil data it could be made smoother since I am sure that those levels will not work.