This sounds awfully similar to T39504…

Jens, thoughts?

Hi
Watched the example video and must say i have no clue whats causing this atm..
T39505 was more the changed nicing prio issue afaik.

This one looks much uglier.

It looks we may have a problem limited to certain machines here and i saw something
like this in the intet, where Adobe claims they identified a bug with newest Apple build
env causing wrong instructions. The root problem is new stricter clang bringing up
a longstanding system lib issue more prominent.

Thats all speculative but i have a testbuild done with former 2.69 build env ( gcc-4.8.1 )
that could give us insight if we are affected here.
So please test this 2.70a done with alternative compiler pls.: http://www.jensverwiebe.de/Blender/blender_2.70a_gcc_physical_threads.zip

Don't worry about the odd name of the zip, it was intentionally made to check another issue.

Enthymeme, would be nice if you report back soon ....

Jens

Hey Jens,

Downloaded the version you provided, and the bug seems to be re-occurring in that build. The jitter is just as bad.

Also, quick note: I realize that the video I uploaded doesn't really give an accurate depiction of the jitter, since that video is at 30FPS. The jitter is actually occurring at the rate of my screen refresh, which is 60hz (I think!). I can record a higher frame-rate video if you would like.

Let me know if there's anything else you need... if it only affects certain machines, that definitely makes fixing it difficult for you.

~Enthymeme

Hi Enthymeme

Thats in a way good news, cause i feared there would be something fishy in my actual build environment.
There is a lot of information around regarding compiler/OS issues, which leaded me to check this assumption
first.

The bad is we must still find out the root reason for your jitter.
Next area to check is the drawing now, pwerhaps something affected by bad video drivers.
I dunno how much technical background you have. It would be interesting if you have the same problem
on another OSX version or on same OSX when switching to software rendering or disable native-pixels etc..

Tell me if you can check:

• starting blender from terminal with the --no-native-pixels option
• try set other screen refreshrate ( if possible )
• try setting other buffer types in prefs ( full, triple, etc. .. )

A bit hazzle i know, but don't have comparable machine to test here.

Jens

haha, not much luck here I'm afraid.

• Starting blender from terminal:

I used:

open /Applications/Blender/bugtest.app/Contents/MacOS/blender --no-native-pixels

bugtest.app being the blender version you attached above, renamed and put in my applications folder.

I got this error: http://i.imgur.com/C2zWLie.png
Not sure of the protocols for starting blender from terminal... any tips?

• try set other screen refreshrate ( if possible )

Unfortunately not possible. I have a macbook pro, and you can't change the refresh rate of the screen for the monitor. I might be able to try plugging into another monitor if that might help.

• try setting other buffer types in prefs ( full, triple, etc. .. )

Done, but to no avail. It was set to automatic by default, and changing it to full, triple buffer, overlap, or any of the others did nothing to change the problem.

Damn :)

.... lemme think ....

And start Blender from terminal without leading "open" just.
Aka: /Applications/Blender/blender.app/Contents/MacOS/blender --no-native-pixels
Other way could be open Blender finder Info and uncheck "start in low res" or how thats called in engl. .

Jens

Ok. So, no luck on the --no-native-pixels. Didn't change anything, the bug persisted.

I don't have a retina display, if that helps at all.

However, Mont29's comment above led me to: https://developer.blender.org/T39094, which seems to be the same issue. The reporter of that bug noted that it is related to the continuous grab checkbox. I can confirm that: When continuous grab is checked, the jittering happens. When it is unchecked, the jitter does not happen.

Additionally, when checking continuous grab in blender 2.69, the jittering happens there as well. Nothing is sacred. ;P

Even more testing led me to discover that it's not just the middle mouse button. It happens when I press [G] to move an object... the transformation starts jittering.

That made me wonder if it happened with any mouse movement at all. I then checked the sliders on the menu, in the render settings. They were not effected by the jitter.

But when I opened up the graph editor and tried to transform a point on an animation curve, it started jittering there as well.

So there's some more info! Does that help?

Aaaaah .... the continous grab was a hazzle for some since ever.
We once fixed it for AMD gpu, but i don't remeber exact where the problem has it's root.
Okay, not a biggie then, will invesigate further.

My hint in between: you must guess ;P

Jens

I see. That's unfortunate!

Can I propose, in the meantime, that Continuos Grab shouldn't be turned on by default? Obviously a bit of a pain, if the user doesn't know what's going on. I imagine new users would be turned off entirely... I've been using blender for 7 years and I was pretty frustrated, haha.

Thanks for your help with the issue!