Redefining previous post: " 3d model a ramp"

[alykto]

When I posed the question about creating a 3d model of a "complex" ramp ,I wasn't very specific about its' outline .The shape of the ramp is what makes my work difficult. It looks like an "s" created by 2 inverse spirals. The problem appears since the ramp follows a curly upgoing path.
I first created the perimeter of the ramp's shape(polyline), then extruded the polyline. After having divided the solid in many segments in an attempt to reach a level of accuracy that would be satisfactory , I started creating slices all over the 3d solid, following the reclination of the ramp.The attempt seems too complex and takes quite a lot of time to achieve. In addition, the result isn't good enough,smooth enough. since when rendering the model, edges appear along the path.Accuracy is important too, for afterwards mechanics will use the model I will create, in order to construct the ramp...

[craigp]

Do you mean it to be like a spiral ramp???

[aledtaylor]

Draw 2 polylines defining the sides of the ramp.

Join them together with lines at their ends.

Use an 'Edge Surface' to create a surface between them. (Set surftab1 and surftab2 to 255 beforehand for the smoothest curve).

Use the lisp routine 'm2s.lsp' to convert the surface into a solid.

Aled Taylor
Design Engineer

[craigp]

This is difficult to draw up but this is as close as i could get. Sorry i can not help further.

Good Luck

[VERYCIVILDRAFTER]

Accuracy is important too, for afterwards mechanics will use the model I will create, in order to construct the ramp...

Will the ramp have to be wheel chair accessible? I ask because you're looking at tough design criteria if you're in the US. If you are not exceeding your maximum allowed slope then...
break your ramp 'center line' into several even length 2d polylines...
that will let you calc the vertical change over each segment...
then that will let you calc 3dpoints at the 'center line' of the ramp...
then just draw a 3dpolyline, snapping to each of the 3d points...
Then you can do what ever 3d jazz you guys do to make it look per'ty.

If you still need to design the ramps length to meet handicap accessible required slope... call your friendly neighborhood Civil Engineer.