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IDProjectCategoryView StatusLast Update
0004751ArchBugpublic2021-09-24 13:20
Reporterhlg Assigned To 
Status newResolutionopen 
Product Version0.20 
Summary0004751: Wrong shape generation for ArchStructure with non-normalized node coordinates
DescriptionWhen a beam is created, nodes are normalized to the internal model with second node at (positive length, 0,0) and rotation, hence beam axis aligned to local x-axis and rotation stored in placement. Then subsequently, only length and rotation are used for shape generation. For example, if a beam is entered with node coordinates (0,0,0) and (-4010,0,0), they are normalized to (0,0,0) and (4010,0,0) and the structure rotation will be set to 180° around z-axis (see example file in forum discussion.

With a legacy file, where at one point apparently shapes where generated differently and node coordinates where not normalized, the once properly generated shape may have a wrong orientation after recompute. Also, when node coordinates are edited directly, they are not normalized and length and rotation are not updated, leading to the same discrepancy between node coordinates and shape.

Instead, I believe normalization should be checked and recalculated to the internal model before shape generation and on change of node coordinates, but I cannot oversee the implications on previous behaviour and potential legacy files.
Steps To Reproduce1. Open the file from forum
2. Switch on node display for the structure and observe generated shape.
3. Recompute shape.
4. The shape will be in the wrong place.
TagsNo tags attached.
FreeCAD InformationOS: Windows 10 Version 2009
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24291 (Git)
Build type: Release
Branch: releases/FreeCAD-0-19
Hash: 7b5e18a0759de778b74d3a5c17eba9cb815035ac
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.0
Locale: German/Germany (de_DE)



2021-09-24 13:18


1_before-recompute.PNG (3,471 bytes)   
1_before-recompute.PNG (3,471 bytes)   
2_after-recompute.PNG (3,055 bytes)   
2_after-recompute.PNG (3,055 bytes)   


2022-03-03 13:55

administrator   ~0017095

This ticket has been migrated to GitHub as issue 6264.

Issue History

Date Modified Username Field Change
2021-09-24 13:18 hlg New Issue
2021-09-24 13:18 hlg File Added: 1_before-recompute.PNG
2021-09-24 13:18 hlg File Added: 2_after-recompute.PNG
2021-09-24 13:20 hlg Steps to Reproduce Updated