How do I get an exact spline from a 3d polyline

[Anonymous]

Hi,

I have some alignments that I have converted into 3d polyline objects

I would like to use these 3d polylines as path for placing families in Revit. Those must be also correctly georeferenced.

Since Revit does not recognize 3d polylines as path for Sweep or Blend (the path must be a spline in revit!!), I have to consider an another workaround.

So in order to achieve that goal, I tried to convert my 3d polylines into splines in AutoCAD using controlled vertices.

The final result seems to be ok but it is not exact or accurate.

I would like pretty much to have an exact spline from the 3d polyline that is georeferenced. 

I am open to any ideas that can serve as a workflow or as a universal approach to solve such problems.

[Kent1Cooper]

I would suggest you try this:   Draw a temporary Spline, starting at an end of the 3DPolyline and going anywhere, JOIN the two together [which will result in a Spline, and I think quite accurate to the shape of the 3DPolyline], and then BREAK the resulting overall Spline from that joint location to remove the part that was originally the temporary Spline.

[leeminardi]

If you want a spline with straight line segments between user specified points use the CV (Control Vertex) method and degree =1 and then input the vertices of the 3dpoly using osnap.  

For example:

Command: SPLINE
Current settings: Method=Fit   Knots=Chord
Specify first point or [Method/Knots/Object]: m
Enter spline creation method [Fit/CV] <Fit>: cv
Current settings: Method=CV   Degree=3
Specify first point or [Method/Degree/Object]: d
Enter degree of spline <3>: 1
Current settings: Method=CV   Degree=1
Specify first point or [Method/Degree/Object]:
Enter next point:
Enter next point or [Undo]:
Enter next point or [Close/Undo]:
Enter next point or [Close/Undo]:
Enter next point or [Close/Undo]:
Enter next point or [Close/Undo]:
Command: