Making not closed but connected lines ?

is it possible to draw lines which are connected (in some way) but do not form a closed wire ?
I would lile to partion the layout in a set of adjacent polygonal cells. To do that I need to draw set of lines which, when extruded along z, generate the vertical faces shared by adjacent cells.

Comments

  • You can draw a path with zero width. This is a valid feature and is equivalent to a line.

    Such paths however vanish on "area aware" functions such as boolean operations.

    Matthias

  • Hi Matthias. Thanks for the hint.
    But I am wondering if a 0 thickness path segment is exported in the dxf file as a true line segment or as a degenerate rectangle. I mean a rectangle with two coincident edges and two degenerate edges. If the latter is true the vertical extrusion of a polygonal mesh defined by such 0 thickness paths will generate many concident/degenerate faces.

  • @wsteffe A zero-width path is written as a POLYLINE with width 0. It's a special case of a path with non-zero width which is also written as a POLYLINE with constant width.

    I don't know how such an object is extruded though.

    Matthias

  • I think you mean an open polyline. Im sorry for the silyy question.
    My confusion arose by the fact that I didn't know how these planar objects are represented in 2D formats like dxf. I was thinking that a path segment with a finite width had to be represented by a rectangle (a closed polyline). That would be the case if this geometry were described in a step file or in an OpenCascade (brep) file. But now I have seen that in the dxf format a polyline has an associated width. So I imagine that a path with a finite width may just be represented by an open line with the associated width.

  • Oh yes ... DXF does not really have the concept of a polygon (except HATCH which also is not really a polygon or at least not a useful object). DXF represents polygons by their outlines, either as a single closed polyline or multiple segments.

    A finite-width polyline is more or less well defined. But that's not a polygon then :)

    Matthias

Sign In or Register to comment.