Autodesk / Autodesk/revit-ifc

Revit fails to handle indexed poly curve with ifc arc index

Open
#359 4 comments 0 reactions 0 assignees View on GitHub
geometry problem
Dominant language
C#
Stars
637
Forks
225
PR merge metrics
No merged PRs in 30d

Description

A little digging in the arcs seem that Revit seems to glitch out when parsing geometry from arcs like this:

```
#16374=IFCCARTESIANPOINTLIST2D(((1010.,60.),(730.286976033,735.286976033),(55.,1015.)));
#16376=IFCINDEXEDPOLYCURVE(#16374,(IFCARCINDEX((1,2,3))),$);
```

I expect a quarter arc like that of a door swing, but I get funny arcs like shown below:

![image](https://user-images.githubusercontent.com/88302/136883054-3e89409e-6927-46e4-93b8-722996b5cfcc.png)

Contributor guide

Open the contributing guide

Research direction

Start by reproducing the supplied IFC Cartesian point list and IFCINDEXEDPOLYCURVE with IFCARCINDEX in Revit, then trace the geometry parsing path for indexed poly curves and arcs. Compare the result with the expected quarter arc shown in the report; done means the example renders as the intended door-swing quarter arc without introducing incorrect curves.

Written by the indexing model from the issue text.

Assessment

Tech stack
csharp
Domain
computer-graphics, desktop-dev
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
45/100

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