Bug: Assimp incorrectly places 3dface inserts

[seanth]

Describe the bug
When viewing a dxf file consisting of two 3d faces--a base rectangle and a small sphere--Sketchup and Autodesk render the image correctly. Assimp exports stls and objs that place the sphere in a very different location

To Reproduce
Steps to reproduce the behavior:

1. Install assimp
2. run the command 'assimp export .dxf .stl
3. open resulting stl
4. see the sphere is not centered on the rectangle

Expected behavior
expected behaviour is that inserts should be inserted at the correct coordinate

Screenshots

Platform (please complete the following information):

• OS: Mac OS 12.6 and 13.5.1
• Browser: not applicable
• Version: Version 5.3 -shared -st (GIT commit 0)

Additional context
example dxf file used in the above screenshots
inputFile.dxf.zip

[seanth]

After doing a lot of experimentation, I'm fairly certain that when scaling is applied to inserts, the scaling is also being applied to the positional arguments. So not only is the scale changing the xyz scale of the inserted block, it is shifting the xyz position of the block.

Edit: I'm very sure this is the issue. If I manually edit the xyz position values by dividing them by their corresponding xyz scaling values, the inserts are placed at the correct locations. This implies that somewhere there is a section of code saying pos*scale. Since the same error in placement shows up regardless of the export format, maybe the bug is in DXFLoader.cpp, but I am not very good with cpp and can't see where it might be.

[seanth]

I think I have resolved the issue

seanth@7c9e1d7

Changing the order of operations so placement of the inserted block happens before scaling seems to fix the problem when the position xyz values are multiplied by the scaling values.

I will test more before submitting a pull request

[seanth]

Fixed by #5426

[seanth]

Fixed by #5426