#198 rendering bug in revolved solid

unexpected behavior
closed-fixed
Raytrace (49)
5
2009-01-19
2008-12-22
Dan Falck
No

I ran into a shape that didn't render very well, while trying out the 'revolve' command. The sketch was generated in QCAD as a dxf and converted to *.g file with dxf-g. I am attaching the *.g file and a screen shot (not sure if I can do 2 files at once). Other, simpler shapes (rectangles) do render fine. This is using a recent svn of brlcad (7.14.2) built on Ubuntu 8.04 32 bit on Intel dual processor with Nvidia Fx700 (I think) card.

Discussion

  • Dan Falck

    Dan Falck - 2008-12-22
     
  • John Anderson

    John Anderson - 2009-01-18

    The problem is that the sketch that is the basis for the revolve has each line segment appearing twice, i.e., there is a line segment from vertex #1 to vertex #2 and another from vertex#2 to vertex#1. Since the revolve intersect routine counts line segment crossings to determine the interior/exterior of the primitive, the duplicate line segments confuse it. The error that is causing this might be either in the dxf-g converter or in the revolve command (or perhaps QCAD is producing an odd sketch with duplicate line segments). If you could provide the dxf file, I could investigate a bit further.

     
  • Dan Falck

    Dan Falck - 2009-01-18

    offending qcad generated file

     
  • Dan Falck

    Dan Falck - 2009-01-18

    Hi,

    I am attaching the file-generated by Qcad 2.0.5.0 Community edition

    Thanks for looking into this.
    Dan
    File Added: prof1.dxf

     
  • Dan Falck

    Dan Falck - 2009-01-18
     
  • Dan Falck

    Dan Falck - 2009-01-18

    I attached the wrong drawing last time (prof1.dxf is in the wrong orientation). I am attaching prof2.dxf that I think was the one that I converted to a brlcad sketch.
    File Added: prof2.dxf

     
  • John Anderson

    John Anderson - 2009-01-19

    This issue has been resolved in the latest (unreleased) version of the source code. Thank you for bringing the issue to our attention! You're welcome and encouraged to test and make sure this issue is resolved after the next source release of BRL-CAD.

     
  • John Anderson

    John Anderson - 2009-01-19

    The dxf-g converter was creating two line segments for each line segment in the dxf file. This is corrected in the latest sources

     
  • John Anderson

    John Anderson - 2009-01-19
    • assigned_to: nobody --> johnranderson
    • status: open --> closed-fixed
     

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