road modelling

[tica]

I need to model a road with great accuracy. I have a 3d spline that defines the middle axis of that road, and I know how large the road should be in the end. I am not very experienced in LW, and all the commands I've tried have not given good results. Does anyone have any experience with road modelling?

[meshmaster]

in theory all you should have to do is grab all the points on that spline, and use point extender... then use move tool with numeric pad to move the new points out x meters along one of the axis and then do the same for the other side... making sure to get them exactly same size.

[Baloney Pony]

Originally posted by tica
I need to model a road with great accuracy. I have a 3d spline that defines the middle axis of that road, and I know how large the road should be in the end. I am not very experienced in LW, and all the commands I've tried have not given good results. Does anyone have any experience with road modelling?

To clarify; you have a spline running down the middle of the road, where the lane line would be? And you know the width of the road? Correct?

If so, you could build a profile of the road and use Rail Extrude. If there are variations in the road width there is a more complex method of doing this -

[tica]

I can't offset this center profile, because this is a closed track, and offsetting it in any given direction will be wrong at several other points of the track. I've also tried rail extrude, but the results I've obtained are not good enough (I read the manual, and I have experimented with that command for a few hours, adjusting the settings, but it still gave me some problematic results at several points of the track). Basically, I was wondering if I did miss something, of if there might be a plug-in out there that could be useful for the task I have to do. Thanks for your help so far, and thanks in advance for any further suggestions!

[tica]

And yes, I have a spline that defines the center axis of my road (track), and I know how large my track is supposed to become. You are correct

[Baloney Pony]

Originally posted by tica
And yes, I have a spline that defines the center axis of my road (track), and I know how large my track is supposed to become. You are correct

I am kind of working blind here on what you need, and what results you have gotten so far - and what part of those results are undesireable. But I will take a stab at it, and when you get a chance if you care to post a few pics of what it is you are experiencing then I may be able to help some more.

So you have a closed track.

Running down the center of the track is the spline which defines the shape of the track.

Let us assume that the track has areas that are narrower than others, and also areas that are banked. Doing a simple Rail Extrude will not accomplish what you want because you have a sinlge curve and that does not provide the tool the needed information to make the track as you like.

So, try this.

Instead of using Rail Extrude - use Rail Clone. Hopefully the curve will have "knots" at the areas where the track narrows and banks. If you do a Rail Clone, and choose the number of segments to match up with your Rail Clone (set to Uniform Knots) you will get a cross section at each of the knots.

With each of the individual sections selected, you can scale - for narrowing the track, or rotate - for banking the track, to give you what the track should look like at the particular spot.

After that, start selecting points on each of the cross sections around the track. Start at the same spot as the original curve. Select the same point on each of the cross sections as you work your way around the track. Then make a curve. You may need to make a number of curves to control how things work.

When you are done - cut all but the original cross section and place them on a temp layer in case you mess up. Then do the Rail Extrude again - only this time it is a Multiple Rail Extrude. Hopefully the extra curves will give you want you want.

The Rail Clone provides you the ability to define how the track will look at that particular cross section when you do your rail extrude. The more curves, the chances are the better the result will be. Be patient. Take your time and I am sure you will get the results you are after.

Good luck!