Drawing roads

[Clint]

I'm real new at this, but everyone starts somewhere.

I'm using Autocad 2005 and I want to create solid road that winds along a path following terrain. I create the path using a 3DPoly line and can extrude a solid face along the 3DPoly line, but when I chage the 3DPoly line to a SPLine it can't be used as the path anymore.

Is there some way to make this work. I want the roads to flow in arcs, not just go from point to point.

Thanks in advance

[csiarch]

Did you try a 3D polyline w/arcs. A little more work than the spline "quick fix" but as you've already discovered, splines don't work.

Maybe trace over your splined object with a 3D polyline? Eyeball the arcs unless you need to be more precise.

Hope this helps..... :)

[Clint]

I did the 3D Polyline trace. Sometimes it worked, at others it didn't. I'm not sure if there is a constraint on the arcs or if this is an autocad thing. I'll try to do the tracing in small increments to see if that works. I also drew a direct spline and got that to work at times. I'll keep testing. You would think that this wouldn't be a problem. I can't be the only one making roads. I'll let you know what happens.

[VERYCIVILDRAFTER]

Is this road for fun or for profit?

Since you’re using plain old AutoCAD to draw the road... I would draw your road alignment using 2d Polylines/arcs at a Z (elevation) of 0. Once you get a desired 2d alignment hammered out put it on a locked layer. I would then retrace the road in 3d using 3dpolys but...

If you have a terrain "model" (contours or a triangulated surface) you can use the "Point Filter" object snaps to make the 3dpoly in 3d fairly easily.

If you don't have a terrain model after tracing the 2dpoly you'll have to edit the Z geometry on the 3dpolyline one point at a time using the Modify Window.

[Clint]

This is non-profit but also not for fun. I'm designing a city layout and am primarily designing buildings to place in the city. The city requires roads that follow the terrain. The city is approximately 180 acres with around 900 buildings. I then take this layout into 3D Studio Max ver 7 and export to another format which allows me to actually walk around in the city and through the buildings. I've already done this for a smaller version with around 90 buildings which all lays on the same Z axis. AutoCad gives me the accuracy, 3D Studio Max gives me the texturing and ability to export in the proper format.

I know how to make the path which winds around the 180 acres. The problem is making the solid extrude along it. When I create the 3D Polyline the solid won't allow me to pick the Polyline as the path.

I've already made the roads using 2D Polylines and now want them to go in the Z direction. Is there a way to move points on a solid in the Z direction. If there is then all I'll need is to do a point edit on the existing roads. Course that won't make the road flow along the terrain like a 3D Polyline would, which is what I prefer since that is how roads actually are made.

I used AutoCad 2005 and Arch Desktop 2006. Same results. I'll do some testing today and see what happens.

[VERYCIVILDRAFTER]

Well you have pretty much described everything I do (with the help of a survey crew) “for profit” in AutoDesk Land Development Desktop and Civil Design. You’d have a difficult task ahead of you, even if you had those tools.

You might consider going about this task in a totally different way.
If you’re doing this as an exhibit, then all of the information you need is probably already archived somewhere.
Does the city or county have an existing online GIS Map? You most likely won't be able to do a 3d model but you'll be able to provide a ton of realworld information.

Here's an example of what I mean. You'll notice it can display contours and overhead photos. http://gis.co.arapahoe.co.us/arcims/viewer.htm (zoom in really tight near the far left)

If something like that isn't avilable to you, you might consider using a varity of sources (in the USA = USGS, www.nationalatlas.gov, or www.TOPOZONE.com) or global http://www.spaceimaging.com/

[VERYCIVILDRAFTER]

It kind of sounds like your doing a Conceptual Site Plan... I know a lot of planners that just make multiple print outs of the site with existing contours and adjacent roadways/utilities. Then they grab a pencil and a scale and start sketching until they get something the client and the city can agree upon... then they mail it to me to fix it. :wink:

Seriously though thats about the extent the have to go to. They just have to follow the Municiplities requirements and the clients wants and needs. I would call the city planning department and ask what they would expect to see.

[Archimedes]

hey, ive read that u use 3ds max... why not use it and make it there instead of making your road network of your conceptual plan in autocad it would only take more time maybe your building can somehow be made accurate in a flash using autocad but modifying polygons/solids in cad will be a long process or time consuming... u can make the modification in 3ds max since you can change it directly on the polygon/solids itself not unless your also new in 3ds max...



"Practice makes perfect, Perfect is flawless"... ü