Convert 2 x 2D spline/pline to 3D

[ssredman]

Hi All,

 

What i am looking for is a way to convert two splines or plines into a 3D spline or pline.

 

So i have two curves, one is on the x,y plane and the other on the x,z plane. I need the 3d x,y,z curve.

 

Extra points if there is a way for both the curves to be displayed in x,y and then you choose which one corresponds to x,y and x,z in the 3D curve (as i usually work in the x,y plane).

 

I am an civil engineer that uses curves in plan and elevation and need to see that curve in 3d.

 

 

 

 

Im using AutoCAD 2014.

 

All help is appreciated.

 

Thanks,

 

Luke

[MSasu]

I will do it like this:

1. Call FLATTEN to convert the splines to polylines.
   
2. Use COPY or OFFSET to build a closed contour for both - will have to add, for sure, two lines to connect the ends; don't forget which was the original edge.
   
3. Extrude the newly created contours - the one in XoY plan to positive Z; for elevation one make sure it fully intersect the first.
   
4. Get the common part by INTERSECT.
   
5. EXPLODE the resulted solid and its faces.
   
6. Retain only the edge resulted from original curves (see point 2).
   

It will not be a single entity, but will be your desired curve.

[SEANT]

The Intersect command can utilize Surfaces, if that makes the process easier.

[MSasu]

Thank you for correction, I wasn't aware of that.

For sure extruding directly the curves to surfaces and intersecting them will simplify a lot the process, although the result will still be a set of curves and not a single one.

[ssredman]

Perfect, that worked very well.

 

I appreciate your speedy reply.

 

Many thanks from Hong Kong!!!

[SEANT]

As an interesting aside, surface formed from splines (Degree 3 splines specifically) seem to do better with intersections than their polyline based counterparts.

SurfIntersect.dwg

[BIGAL]

Are we not talking about profiles here in a CIV3d sense a built in function of basic road design. Outside of CIV3D some of the freeby software that does long section design could also be used. Is this Ssredman what you want ? You say your a Civil engineer.

[ssredman]

Hi Bigal,

 

I am using this for steel cable profiles for a bridge rather than road geometry design. I appreciate the thought though.