What is happening to Dear Open CASCADE

What is happening to OpenCASCADE. It seems they are not very happy distributing it in a friendly manner. First they cut short the documentation which was once very comprehensive. And now the Linux distribution??? You have to take a lot of pains just to get started. And in-spite of following all their instructions the code did neither compile nor install properly. All libXXX.so files other than TKernel was generated with size 0. And the make install command fails with an error "cannot stat envDraw.sh".

I think as far as usability was concerned Open Cascade 4.0 was best. The library contents may be improving... that too, much with the valuable feedbacks of the community. But as far as ease of use is concerned it is becoming poorer with every release, with new as well as experienced Open Cascade users too.

Linux users were given secondary treatment from the beginning itself. None of the MFC Samples on windows are available in c++ format on Linux. It could have been easily (I insist, very easily) ported to Linux using Qt or GTK+.

I humbly request the Open Cascade team to look into these issues and kindly put OpenCascade users in a more convenient position.

Thanks and Regards
N. Sharjith

Roman Lygin's picture

I am sitting on Windows, so have no issues you are referring to. Moreover, I believe documentation is now way more elaborate than it was in the past. With introduction of Doxygen-style comments in source code you should now be able to easily navigate through entire OCC hierarchy (not just read CDL files). Release Notes of 6.3 state there are new white papers, so these should be helpful as well.

Regarding removal of Linux binaries, I can guess this was done to reduce the download image size and to be more compliant with Linux community conventions. Open Source on Linux is primarily distributed in source code only, and binaries are built on user's machine.
I never tried myself to build OCC on Linux using make files (always used WOK), so won't speculate much on how difficult it is but if you are familiar with OS build tools there should not be significant problems for you. Anyway, build instructions in the doc should help.

I believe in general convenience of installation and user's experience of 6.x is far better than what existed in 4.x or before. Windows install is just seamless - it takes you a flew clicks, some time to install, and there you go. Rebuilding entire code on my machine in Visual Studio was totally painless - just had open each .sln file and press F7 (even after 2 years of my last development on OCC :-)).

As for samples, yes, Windows has a richer set. That's partly due to legacy (MFC was designed first) and because mainstream is still Windows. Qt (and Java) example should be enough to get a clue how to build a framework app to have OCC run on Linux, and having access to Windows samples source code enables you to enrich functionality. Wouldn't you be able to add Boolean ops to your Linux app reading MFC sample ? Of course, you would. But for the company to migrate legacy code from MFC to Qt (or other toolkit) would be a one time effort + regular effort to maintain multiple platforms.
In the end of the day, they run business and have to prioritize their R&D projects, and I believe extension of the docs, new nice features were better investments that would have been porting their MFC samples to Qt.

Just my opinion.
Take care.

Sharjith Naramparambath's picture

Hi Roman Lygin,
I think you are right with most of the points but for some. Imagine a person having only Linux on his machine. How do you expect him to install the Feature Rich windows setup and see all the good examples of MFC (Note there are beginners to OCC too...).
But I still have high regards for the Open CASCADE team.(Remember I said Dear OpenCASCADE). And I frankly appreciate your true opinion.

N. Sharjith

Roman Lygin's picture

Hi Nair,

Glad to see my opinion has met your understanding (at least in major points).
Regarding Linux-only environment. Frankly, I would hardly believe there is someone using OCC at his home in a fully isolated environment. Even if there is such a freak (no harassment :-)), he/she can certainly find friends around to install Windows version and grab the source code. Any other use implies some group environment (lab, corporate, etc) where at least one Windows box will be found. So probability is extremely low.

Take care.

P Dolbey's picture

I think it would be quite a nice idea to develop Qt (or GTK) versions of the MFC demos. If anyone is interested in Qt4 versions, I'd be happy to host them at the qtocc Sourceforge site.


Sharjith Naramparambath's picture

In the intrest of the community I have already ported the ImportExport demo to Gtk and Pete has hosted it on his website. I think this can also serve as a platform for all the other MFC Examples. I will also try to port some as and when I find some time.

To all the forum members I request to please look into the GTK code hosted on Pete's site
and possibly contribute to the development of MFC Samples for Linux.

N. Sharjith

Stephen Leary's picture

As a person who has recently had to start using OpenCascade I have to say I find the whole package to be extremely incoherent. Particularly with regard to finding examples and the distibution formats/searchablity of the documentation and the literally hundreds of bugs i have come across.

I also have found that the very very simple things I would expect to be able to do in any geometry system are painful, have very few examples, and many of the examples given dont work!

I think there are wonderful things under the hood of these libraries but I find it frustrating how much time i waste finding out how to do simple things.



Roman Lygin's picture

Hi Stephen,

Welcome on board! Well, nothing is perfect in this world ;-).
To judge on something you have to compare it with something similar. Apple to apples, pear to pears. You can't expect a huge complex 3D modeling library as easy to use out of the box, as for instance a GUI library. I bet other 3D kernels (with licenses worth dozens K$) will not offer you perfect user experience. Well, I tried some. And keep in mind entry costs - which are actually your time only, unless you require a commercial support or paid add-ons.

Take your time, look around, make little steps, try small things and you will feel better.
Don't panic and don't get frustrated.
Good luck.

Divya's picture

fatal error LNK1149: output filename matches input filename
how can I fix this?