We have a lot of Mac users on Blender, we rarely have a report like this come in.

Such problems are typically for opengl windows... driver issues. It seems 10.6.6 is the latest upgrade from Apple? Did this run fine before?

When you say "We rarely have a report like this come in", are you referring to the nature of the problem or the detail in the report? :)

I can't comment on 2.56a-beta prior to 10.6.6 - I d/led 2.56a-beta about 3 days ago.

But prior to Mac OS 10.6.6 I used 2.49. No trouble.

FYI: Total noob at Blender here - I use it for model building at the moment. I'm tentatively exploring particle physics and I thought any number of complex things could go wrong, but... but... window resizing??? That one came out of the blue.

"Resizing Blender window hangs system" is very rare, it happened when we were totally recoding parts only.
What I do know is that occasionally Apple messes up drivers on upgrades... the iMacs were not really meant for serious 3D work I guess.

I'd be prepared to agree it might be a driver problem due to an upgrade oversight, but I'd disagree about iMacs not really meant for serious 3D work.

The current iMac line has the power and functionality to do all the 3D work done in big budget movies 5-7 years ago. My point is, "serious" 3D work is a matter of speed and capacity, not whether the computer has the IC architecture to do it or not. iMacs are more to the domestic end of the PC market, that's a fact. But a crash is a crash: either Blender is not able to be run on an iMac at all (and it does - I rendered out a simple 10s particle emission movie out of 2.56a-beta a day or so ago, and I can still use 2.56a-beta just fine), or there's something wrong in the software, which ANY Intel Mac can run.

As window resizing uses a bunch of standard APIs the buggy culprit can't be too hard to spot: either Blender is doing something wacky or, as you say, something in the latest OS update is screwy. I've been caught out before with a screwy Apple update: Then again, Blender 2.56 is not out of beta. All I can do is submit error reports and hope something comes right soon.

On my PPC G5 system this works fine, so is on my macpro with ATI. Also testers I've asked couldn't redo this.
There's always a chance our code fails to do something that's being forgiven on other systems. However, we can't do anything until it's reproducable :)

I can't reproduce it either on my MBP (C2D 2.8GHz, 9400M, 10.6.6 64bit)...

Damn. OK, here's what I did: I obviously can't screen-capture a hung computer, but I did a few things, maybe this will help.

I rebooted the comp and ran through the same procedure as detailed in the first post. On resizing the window: if I shrunk the window down the interface cropped-to-size, rather than resized the various palettes on-the-fly. Also, while keeping the mouse down, if I kept the mouse down while dragging, the cropped interface didn't re-draw - there was just white screen drawn between the small-cropped interface and the rectangle drawn from the top-left corner and wherever the mouse was positioned. There were also corner or mouse-trails drawn wherever the mouse was dragged. On mouse-release, the computer hung.

I rebooted in <a href="http://support.apple.com/kb/HT1564?viewlocale=en_US">Safe Boot mode.</a> (Hold shift key down on Mac restart). This turns off a lot of non-essential services in the OS, including Quartz Extreme, which might be significant.

After opening, Blender worked fine, but notable differences were that the pop-up Start window wasn't visible, blender operation was at a very low frame rate and the interface looked flat. However, resizing the window, while strobing, worked fine. I could resize and move the window around the screen with no problem.

I took handheld photographs of the screen for both tests, and submitted a(nother) bug report to Apple via their auto-generated Problem Report. If you guys would like a copy of the report, which is basically a whole bunch of colon-separated hex values for arcane system calls, I can repost it here. Let me know if you want the photos.

We have a bug in our tracker, you have to write text first, then attach files and submit.

I would recommend you to test blender on another system too, when you have it available.
On macs, the UI only redraws when you release the mouse button after making it smaller. That has been done to prevent crashing too, redraws of opengl while you size windows was not stable.

Thanks for all the testing though!

Submitting attachments.

http://dl.dropbox.com/u/13900881/blenderProblemReport.rtf

http://dl.dropbox.com/u/13900881/TotalSystemCrash.jpg

Interesting... this looks like as if the Mac Cocoa system doesn't register the resizing at all.

Damien: could this be related to the (maybe non-standard) option we have to not redraw while resizing?

Not redraw while resizing leads to the blank that appears when the mouse button is down changing the window size. The reason for not redrawing is due to a rounding issue with Blender WM that'll make some regions shrink badly.
It is not linked to the crash.
Reading the logs, the crash happens inside the ATI kernel driver. Thus explaining the total crash.
But that doesn't explain why a window resize makes this driver crash.
Can you try with an older version (you may get on graphicall.org) ?
Can you try with other openGL programs ?

Ton, do you know if the other testers who have not experienced the crash also have ATI HD 2600 ?

I'm not a programmer - what version of Blender would you suggest I try on graphicall.org?

I'm not sure what programs use OpenGL or not - If you could suggest a finished application that tests this, let me know. I do know that this computer has been running fine for two years using many 3D games, 3D design tools and services that probably use OpenGL, but the only crashes I recall involve faulty third party peripherals.

(I have tested 2.56a-beta with no peripherals plugged in. The crash still occurs on mouse-release after interface resizing.)

It looks like this issue is not happening only with Blender, see this thread about CS5 crashes on ATI upon window resize : http://discussions.apple.com/thread.jspa?messageID=12998667

On graphicall, you'll find some older versions (select OSX Intel, and download the oldest).
For other OpenGL programs, the ones I have in mind are the examples given with the XCode package (on your Snow Leopard DVD).

Tested Blender 2.5 beta
Rev. 2.53.1
Build r30140:31142M

General operation fine; fatal crash on window resizing.

OK, Here's something interesting: An iMac user, same specs as mine, tried running the latest version of Messiah Studio and reported exactly the same problem.

http://setuptab.com/index.php?topic=3165.0

It can't be a coincidence.

Where to go from here? Do you guys hassle Apple to find out if they've changed anything with their graphics drivers?

Hi,

It's usually best if someone who has encountered the issue reports to Apple him/herself.
I'll move this ticket to our graphics (opengl) tracker, and will add a note in our wiki about the issue.
As soon as we find a developer who can reproduce the crash, we can work with that person if there's a bypass possible.

Thanks!

Moved from Blender 2.5 Bug Tracker to OpenGL errors