Surface Origin Changing

[Kyle Anderson]

I've been having a persistent, intermittent problem. I am using QLab 4 on a MacPro with 5 video outputs. Three of which are a Matrox TripleHead2Go sending three 1280x720 screens, one of which is a 1280x720 screen, and one is the computer's monitor.

Over the last several months, the Origin of some surfaces will change when opening the workspaces. I am running multiple shows, with their own workspace, and this has happened to all of them. The Origin of every surface is 0,0, but when I open a workspace and look at my test cue, it's blank. On investigating the surface, the Origin will now be -1680,1680. I'll have to manually change it, often for multiple surfaces in the workspace. I'll save and re-open, and it will be fine. The next day, -1680,1680 again. Rinse and repeat. 

Open a second workspace, and the Origins are all still 0,0. Open a third, and they are -9520,9520.

Next day, different ones are fine and different ones are wrong. 

Any guesses? 

[Dan]

Hi Kyle,

I have just seen this behaviour on a 6.1 Mac Pro. My setup is two DVI displays connected directly and one Datapath X4 connected via dual link adapter. The staff onsite do not even open the settings of some surfaces. What OS were you running?

I am on High Sierra with v4.4.

Dan

[Gordon Nimmo-Smith]

Bumping this! I just had the same thing happen on Mojave running Qlab 4.5.4 this morning. I'm running through a DisplayPort TripleHeadToGo on a Late 2013 Mac Pro.

Did anyone ever figure this one out?

Thanks! Gordon

[Sam Kusnetz]

Hello all

The "surface origin changing spontaneously” bug is a long-standing and very irritating one, and to make matters worse, it’s not immediately obvious that the bug even exists inside QLab’s code.

Here’s one thing to try which seems to consistently help the issue:

1. Switch on your Mac and all associated hardware like switchers, monitors, projectors, etc.

2. Do not launch QLab.

3. Open System Preferences and choose “Displays”

4. In the “Arrangement” tab, make an adjustment to the layout of the screens. It does not matter what the adjustment is, it just needs to be different than how it was.

5. Reboot the Mac.

After this little game, you’ll probably need to make an adjustment inside QLab to get your surfaces lined up, but after that, it should be smooth sailing.

What going on when the surface origin moves is often that macOS has a little database of connected screens, and this database can become corrupted, which means that when QLab launches, it believes the screens have moved. Adjusting the arrangement of screens in System Preferences causes macOS to throw out and rebuild the database, which removes the source of the trouble.

I can’t promise that this will solve every case, but it doesn’t take long to do so it’s worth a shot.

Best

Sam

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Sam Kusnetz | Figure 53

s...@figure53.com