NX DXF Export of Smooth Splines Results in 'Choppy' Polylines

2021-10-06T23:27:15Z
NX for Design

Summary


Details

When exporting smooth splines to DXF 2D Polylines, the resultant polylines in the DXF file are not smooth. They appear 'choppy' or 'segmented'.

Solution

In NX12 and earlier, the DXF export algorithm has a hard coded value that breaks each NX spline into 50 segments.  This number is not always enough to create a smooth appearance on the DXF polylines.


The solution is to divide the NX splines into multiple segments, particularly at the the beginning and end of areas containing a lot of curvature.  This can be done using the Menu --> Edit --> Curve  --> Divide.  The options available are as shown:
Equal Segments most often will work, second choice could be At Knots Points.  This is determined by the desired outcome.



Then, the DXF export algorithm with break each of the segments of the divided spline into 50 segments, resulting in a nearly exact representation of the NX spline.


In NX1847 (and newer) this has been enhanced to set "BPLLINE_TO_PLINE_CONV_TOL" (default = 0.08mm).  This is shown in the NX1926 Help.
https://docs.sw.siemens.com/en-US/product/209349590/doc/PL20191127135844554.xid458383/html/xid1396811 




Notes and References


Hardware/Software Configuration

Platform: all
OS: n/a
OS Version: n/a
Product: NX
Application: DESIGN
Version: V1855
Function: CURVE

Ref: 002-7005794

KB Article ID# PL7005794

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