Changes between Version 2 and Version 3 of Ticket #5705
- Timestamp:
- Oct 22, 2014, 3:22:25 AM (9 years ago)
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Ticket #5705 – Description
v2 v3 6 6 The result I obtain is wrong (attached file "sampleb_output.dxf"), as can be verified in AutoCAD. Basically, one of the ellipses in the output has a wrong angle and its X coordinates are wrong. I would expect the same visual result as the input. The issue can also be seen when converting to a format other than DXF (for example SHP). 7 7 8 Doing some investigation inside the input DXF using a text editor, I saw that the ellipse that converts correctly has a Z extrusion axis value (group code 230) of 1.0, whereas the ellipse that was not converted correctly has a Z extrusion axis value of -1.0. I have then done a test when I reversed its Z extrusion axis (from -1.0 to 1.0) and switched+reversed the start and end angles (group codes 41 and 42) in attached file "sampleb_input-mod.dxf". Then the conversion of the previously incorrect ellipse is done correctly (attached file "sampleb_output-mod.dxf"). Visually, the input and ouput are the same .8 Doing some investigation inside the input DXF using a text editor, I saw that the ellipse that converts correctly has a Z extrusion axis value (group code 230) of 1.0, whereas the ellipse that was not converted correctly has a Z extrusion axis value of -1.0. I have then done a test when I reversed its Z extrusion axis (from -1.0 to 1.0) and switched+reversed the start and end angles (group codes 41 and 42) in attached file "sampleb_input-mod.dxf". Then the conversion of the previously incorrect ellipse is done correctly (attached file "sampleb_output-mod.dxf"). Visually, the input and ouput are the same, as well as identical to the original input DXF file. 9 9 10 So it seems that, when the Z direction is -1, on top of having to rotate the points of the ellipse to align with the direction of major axis, the Y axis is alsoreversed. Maybe a transformation to the new coordinate system :10 So it seems that, when the Z direction is -1, on top of having to rotate the points of the ellipse to align with the direction of major axis, the Y axis must also be reversed. Maybe a transformation to the new coordinate system : 11 11 12 12 Direction of new X axis = endpoint of major axis