topic Re: Interpolate 3D polyline with different elevations in Civil 3D Forum

Interpolate 3D polyline with different elevations

Ingrid91 — Tue, 04 Jun 2024 14:11:45 GMT

Hi,

So I've received a file that is a mixture of 2D- and 3D-polylines. My task is to convert these into 3D-polylines with either a) using the elevation from the model or b) using a standard elevation with regards to the surface model.

The problem is that along the 3D-polylines there are vertices with elevation 0. I'm not sure how it was modeled but the end result is very jagged. It'd be easy to draw a 3D-polylines between the vertices with an elevation, but the lines don't go in a straight line in plan view.

Is there a way to get a 3D-polyline or a feature line to snap to the location of a 2D (elevation 0) vertex without gaining its elevation, and make it so that the rest of the height is interpolated?

As it is I've tried to: draw 3D-poly between to points. Made it into a feature line. Added PI to the feature line roughly corresponding in distance to where the vertices are located on the 2D/3D-poly. Turned SNAP on/off to find the vertex but not gain its elevation. It's doable, but it's not exact as I can't snap to the line and it feels time consuming.

See pictures below for clarification.

Re: Interpolate 3D polyline with different elevations

VincentSheehan — Tue, 04 Jun 2024 15:42:10 GMT

If I'm understanding, something like this?

The red line is a feature line at different elevations. The white line is a polyline at 0 elevation. I set the view to ISO. I add PIs to the feature line while snapping to the polyline.

(view in My Videos)

Re: Interpolate 3D polyline with different elevations

Joe-Bouza — Tue, 04 Jun 2024 17:41:22 GMT

.XY in the osnap options may be what you want

Re: Interpolate 3D polyline with different elevations

brian.strandberg — Tue, 04 Jun 2024 18:34:06 GMT

OSNAPZ=1, when you snap to an object with OSNAPZ = 1, you will only get the XY point. The Z will become the current ELEV (usually 0).

Re: Interpolate 3D polyline with different elevations

Ingrid91 — Wed, 05 Jun 2024 07:04:41 GMT

I've googled to try to find what you mean but don't see anything specific regarding .XY

Re: Interpolate 3D polyline with different elevations

Ingrid91 — Wed, 05 Jun 2024 07:06:11 GMT

Unfortunately that won't help, as the elevation that I want the added vertices to receive is the interpolated one. So having it set to =0 means that it would take the 0 elevation, and having it set to =1 means that it would take the current ELEV which is also 0.

Re: Interpolate 3D polyline with different elevations

Ingrid91 — Wed, 05 Jun 2024 07:11:31 GMT

Such a simple solution! Thank you for the clear video 🙂