can't open igs file in MOI

 From:  Michael Gibson
635.14 In reply to 635.13 
Hi Speed, I can understand that you don't like hearing "update your drivers" all the time, but the fact is that buggy video drivers are a constant problem.

When I worked at Microsoft, I learned that the single biggest cause of Blue Screens of Death were buggy video drivers.

Normally it isn't feasible for a regular "user-mode" program like MoI to crash the entire operating system. For the whole operating system to crash requires a driver to do something bad since they run at a privileged level and can access protected kernel memory that a regular user-mode program cannot.

Your full system crash is a very big indicator that something is going wrong at the driver level. It may be due to MoI poking the driver in some improper way that it doesn't expect, or it may be due to bugs in the driver itself.


> Can't buy that absolute conclusion.

Certainly nothing is absolute in debugging. Until you know the problem, you don't know it...

But the clues are very strong that you've got a driver problem, particularly because this is an unusual problem, you are the first person to describe these particular symptoms. If I was constantly getting reports like this (or even just more than one), I would be less likely to blame the driver at first.

One of the best approaches for successfully debugging is to rule out different problems to narrow down the issue. That's why updating your drivers would be helpful because it would help to either validate that it was a driver issue, or rule out that it was a driver issue. As it stands right now it is completely possible that it is a driver issue.

If you can send me the data, or at least try it on a different machine with a different video card that would also be helpful. If the same problem can be reproduced under 2 different hardware environments, that really helps to narrow it down to a MoI issue instead of a driver issue. Crossing things off the list of potential problems is progress in debugging!


> The latest video drivers can't fix all things all of the time and
> some definitely go in the other direction.

Well, here's the thing - if you don't think that buggy drivers are the problem, then why are you worried about updating to new drivers that might be buggy? I mean this itself is a sign that you know that drivers have problems in them!

I've never seen a driver update that is permanent and irrevocable, you should be able to roll back to your current driver (or just re-install the older one) if the newest ones cause new problems.


> Rhino2 opens and translates the file just fine with these drivers, as do a couple
> of other apps, so I'm more suspicous of MoI.

If I remember right, Rhino2 in wireframe mode does not by default use hardware acceleration, I think it draws your wireframe with my old rendering code which avoids talking to the video driver (one thing that is nice about that is that it avoids driver issues, but it does not leverage the power of modern video cards though). And even if you have it set to use hardware acceleration, it and probably your other apps are using the OpenGL system which is a completely different driver system from the Direct3D one that MoI uses...


Don't get me wrong, I really appreciate your bug report and your good description of the symptoms.... But I'm not sure what you expect for me to do about it right now. It is very difficult for me to make progress without any narrowing down or any way to reproduce the problem over here, or even any additional similar reports to look for common factors..

Did you find out if you can send me the data or not?

What about crash dump files (moi_report1.zip), if you can find those and e-mail them to me it would be something I could look at.

- Michael