"Illegal storage access" on STEP file import

[msbentley]

Hi all,

I've just installed FreeCAD 0.7 / 0.8R2237 on ubuntu / jaunty 64-bit. It all runs up OK, however I tried to import a (quite large) STEP file created in another package and FreeCAD crashes with the error:

Illegal storage access

I was wondering if there was anything I could do to get around this?

Regards, Mark

[wmayer]

Hi Mark,

did you build FreeCAD yourself from the sources or did you download & install the .deb package from SF?
Does it work if you load only a small STEP file or crashes it only with big files? If so, you could enter a higher value for "Maximum deviation for tessellated shapes" (under Edit > Preferences > Part Design > Shape view). The higher this value is the less triangles get created but with lesser accuracy.

Anyway it would be interesting to know what gdb does say.

Cheers,
Werner

[msbentley]

Hi Werner,

Thanks for your quick response! I installed from a .deb on SF (freecad_0.8.2237-1jaunty1_amd64.deb).

I have just tried a few small STEP files which load with no problem. A larger file (14 MB) causes FreeCAD to freeze for some time on loading, but works well after that.

Incidentally, the freeze on loading seems to hog window focus (I've tried both compiz and metacity) such that I cannot switch to another window, and effectively takes over the computer for those few minutes.

The problem file in question, saved from another app (not by me, and I don't have access to the source, sadly) is ~75 MB.

I tried increasing the max deviation parameter, and this (subjectively) seemed to get it to run for longer during the import process before crashing, but ultimately it failed with the same result.

Running with gdb, I get a segfault at:

0x00007fff06565145 in StepToTopoDS_TranslateShell::Init () from /usr/lib/libTKSTEP-6.2.so

Cheers, Mark

[wmayer]

Hi Mark,

I have just tried a few small STEP files which load with no problem. A larger file (14 MB) causes FreeCAD to freeze for some time on loading, but works well after that.

This is because the whole loading is done in the GUI thread and thus cannot response as long as the file is loading. I think we should think about doing this in a separate thread to keep the GUI up.

Incidentally, the freeze on loading seems to hog window focus (I've tried both compiz and metacity) such that I cannot switch to another window, and effectively takes over the computer for those few minutes.
[/qupte]

Hmm, when loading a larger file I still can switch to another application...

0x00007fff06565145 in StepToTopoDS_TranslateShell::Init () from /usr/lib/libTKSTEP-6.2.so

Is this the whole output of gdb? It's not much but it seems to be a problem with the OpenCascade library.

Cheers,
Werner