Hi all, Sorry for a somewhat long post, but here we go: I am converting a .dxf having a sequence of simple lines and arcs which form a continuous (poly)line, (correctly) ordered by EntityHandle. The arcs are converted (to shp) as well as displayed (Qgis) in the opposite direction as the simple lines. Checking the codes and docs, this appears wrong. Below the minimal relevant information, I can add the complete .dxf, but I think attached files are frowned upon?
Docs cited: https://help.autodesk.com/view/OARX/2024/ENU/?guid=GUID-0B14D8F1-0EBA-44BF-9108-57D8CE614BC8 ARC (DXF) The following group codes apply to arc entities. Arc group codes Group code Description 100 Subclass marker (AcDbCircle) 39 Thickness (optional; default = 0) 10 Center point (in OCS) DXF: X value; APP: 3D point 20, 30 DXF: Y and Z values of center point (in OCS) 40 Radius 100 Subclass marker (AcDbArc) 50 Start angle 51 End angle 210 Extrusion direction (optional; default = 0, 0, 1) DXF: X value; APP: 3D vector 220, 230 DXF: Y and Z values of extrusion direction (optional) https://ezdxf.readthedocs.io/en/stable/tutorials/dxf_primitives.html The arc goes always in counter-clockwise orientation around the z-axis more precisely the extrusion vector of OCS, but this is beyond the scope of this tutorial. The case (extracted, whole .dxf file available): AcDbEntity 8 0000-001_09_AND1N 6 Continuous 62 18 100 AcDbCircle 10 130974.661837 20 497502.478468 30 0.0 40 7576.094430000001 100 AcDbArc 50 305.5444330000001 51 344.795475 0 LINE 5 2E 330 1A0 100 The arc is converted (.shp) and drawn (qgis) from end angle to start angle, without a 210 code to alter default behavior, which obviously is the other way around, noting counter clock around (positive) Z-axis. The applicability of this convention also follows from the (correct) position of the arc in the conversion and drawing. Only begin- and endpoints are interchanged. Please advice, Thanks in advance, Jan
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