twisting ramp

[squirrelboy71]

O.k., here's one for the pros out there. I wasted a day trying to do this.

I have a ramp that is curving in plan (in various directions, like a winding path) as well as increasing in height at various rates along it's length.

I've tried to extrude along a carefully mapped path, but evidently you can't extrude to a nurbs curve that is nonplanar. Using the 3d reshaping tool is just not accurrate enough. I even tried turning my nonplanar path into a helix-spiral, which at least let me extrude. But the path took a sharp turn and twisted under (not good for those who need to walk on the ramp!).

I'd be so grateful for the help. Evidently this project is just going to get worse with twisting shapes. I'd love to find a way to do this so that I stop feeling like an idiot.

Thanks!

[lamberto previati]

Can you post front and top/plan views of your project?

Lamberto

[tom kyler_dup1]

You've certainly picked a good challenging problem. Here's how I would attack it. The technique I would use it to draw both edges of the ramp with nurbs curves, in 3D, and then connect the two with the loft tool. To ensure the best model, you should try to have the same number of verticies on each nurbs curve and make sure the curves have the same direction...then you should have no problem.

The challenge lies in creating the 3D edges, I can't think of a "non-time consuming" way to do that, but you said you have already created a nurbs path. I'll guess it's for one edge only. I would create an equally careful edge for the other edge of the ramp and loft them together. If you have nurbs curves that represent each edge of the ramp and they're placed to your satisfaction, you should have no problem.

In addition, you should try to keep vertices on each edge "opposite" from each other and each "opposing" verticies should have the same Z value (assuming you want a ramp whose cross section is parallel with the ground. In the ramp below, I used the shell tool after creating the intitial ramp to give my ramp some thickness, this is optional. Good luck

[ 08-14-2004, 11:49 AM: Message edited by: tom kyler ]

[squirrelboy71]

Tom!

I think you might be on to something! (Plus your example is remarkably close to what we're designing.)

Thanks for the idea. I'll see if it works for us.