2D Polyline with 3D Verticies

[Anonymous]

I have a polyline in the attached file that does not show any z vertex in the properties box, but when you ID ther verticies, each vertex has a different Z value

The polyline has an elevation, but the z value at the verticies don't match that.

Can someone shed some light on this?

Cheers,

Brent

[3wood]

When you inquire the entity information with LIST command, you will see all different Z value of vertexes.

It is a LWPOLYLINE, not a 2D Polylines, definitely every vertex can has its own Z value.

[Kent1Cooper]

It's not drawn in [or parallel to] the World Coordinate System.  You can tell by the last entry in the entity data list, which is the extrusion direction, meaning the direction [in unit-vector form] of the Z axis of the object in relation to the WCS:

(210 0.000325872 0.000500258 1.0)

For something drawn in the WCS, or in a User Coordinate System parallel to it, that would be:

(210 0.0 0.0 1.0)

so it's pretty close to lying parallel to the WCS.  You can also tell that it's close by the fact that the Z coordinates span a small range in relation to its length.

The elevation of it:

(38 . 168.526)

is in relation to the origin under which it was drawn and its extrusion direction.  For a LWPOLYLINE drawn in or parallel to the WCS, if you List it when you are in the WCS, that number will be the same as all the Z coordinates in the List results.  Or if you set the UCS to match it {UCS command, OBject option], List will show all Z coordinates as 0.

[Ajilal.Vijayan]

Try to convert this pline to 3D POLYLINE

Have found a lisp routine for the conversion