Cities: Skylines (Steam) - Mac Apple M1: Graphics Issues - Screen freezing on camera angle change

[lrstzk]

Describe your issue: Graphics Issues - Screen freezing on camera angle change

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What is your game version? 1.13.1-f1

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What expansions do you have installed? None.

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What mods are you using? None.

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Please explain your issue is in as much detail as possible.

Problem 1:

While playing Cities Skylines (no mods, no expansion, freshly installed 2 hours ago) the screen is flickering. Black frames appear now and then. I'd guess about every 4 to 20 seconds at irregular intervals. That's the smaller problem.

Problem 2:

Occasionally, while changing the camera-angle by clicking the scroll-wheel or using keyboard, the graphic output freezes. Not just the game's but of the whole computer's graphic output is frozen. In the background everything is running fine. The monitor itself seems not to be the issue as I can access the monitor's menu without any problems. If I restart the monitor or un- and replug the HDMI-cable, the graphic output is no more frozen.

What I tried (and it didn't work):

- restarting the computer
- running game in windowed mode
- changing all the graphics settings (from low to high, trying different resolutions)
- disable steam overlay
- forcing the game to use Metal Engine (-force-gfx-metal in steam launch-options)
- changed screen resolution (scaling the ui) in macOS settings

Hard- and Software used:

- Computer: Mac mini (M1, 2020) with Apple M1 chip + 16gb ram
- OS: macOS Big Sur 11.0.1
- Monitor: LG 4k 32UK550/UL500; Resolution 3840x2160/60Hz connected with HDMI

Background info:

The screen freezing problem never appeared yet and seems to be only appearing in Cities: Skylines while changing the camera-angle. Apart from that, the Mac + the monitor are running fine for weeks now.

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Can you replicate the issue? If yes, please explain how you did it.

Black frames appear all the time.

Changing the camera-angle forces the graphic output freezing occasionally. If I do not change the camera-angle the game runs without freezing the screen.

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Attachments (DID NOT ANSWER QUESTION)

 

[AndrewT]

I have other reports of graphical irregularities on M1 machines with our games, in fact our other main Unity game Battletech is one such. I don't think there's any possible fix except Apple updates, or the game gets re-written in native M1 code.

@co_avanya I will guess that's not something CO would countenance at this late stage in the game's life, would that be right?

 

[lrstzk]

Thanks @AndrewT

In the meantime, I was able to find a solution! So I'm posting it here in case others are running into the same problem.

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How to fix graphic output freezing / screen freezing on Mac mini M1 when changing the camera angle in Cities: Skylines​

1. In steam launcher, I changed the graphics mode to -force-opengl like described in the "Mac Troubleshooting Guide - Cities Skylines" in a steam forum (can't post a link here; just google it).
2. Then, I enabled v-sync (I disabled it before when troubleshooting)

Only the combination of both was stoping the screen freeze as well as the black frame flickering.

Other graphic modes with our without v-sync didn't help.

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Maybe interesting for any developers like @co_avanya​

Others using Apple M1 Macs don't seem to have this problem. Online in many sources it is reported the game would rune smoothly. Neither have I changed any graphics options on my Mac nor have I changed anything in the game as the problem occurred. Vanilla Cities: Skylines, current version, basic settings, no mods, expansions etc. The problem occurred right from the first start within the first 2 hours of playing.

 

[co_avanya]

@co_avanya I will guess that's not something CO would countenance at this late stage in the game's life, would that be right?

Correct. It's simply not something that's feasible at this point.

Thank you @lrstzk for sharing your finds! I'm sure they will be useful for other players encountering similar problems, and I'm grateful for the tag as well. ^^

 

[AndrewT]

In steam launcher, I changed the graphics mode to -force-opengl like described in the "Mac Troubleshooting Guide - Cities Skylines" in a steam forum (can't post a link here; just google it).

The game already runs in openGL on Mac ... ?!? Are you sure that shouldn't be -force-glcore ?

 

[ManicMoov]

Thanks @AndrewT

In the meantime, I was able to find a solution! So I'm posting it here in case others are running into the same problem.
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Thanks, this solution worked perfectly for me. I can now run CS on my M1 Mac in full resolution without any freezes - and it runs as smooth as butter