Steam game rendering issues

My Mac is an M2 Max, 32GB
I've been able to run most Steam games without any issues, however, when I tried running Core Keeper there were issues with the lighting (specifically the torches- they give off no light, making much of the game too dark to see anything) which prevents the game from really being playable.

Is there any way to change the rendering options within Parallels? I'm curious if anyone else has noticed these kinds of issues with other games. Any suggestions?
I've tried reaching out to the CoreKeeper discord but not much help there.

 

I found the solution if anyone else has this same issue. You need to add a line to the boot order in the Parallels settings:

1. Close/Shut down the Virtual machine (you can't change settings while it's running)
2. Click the Parallels icon in the menu bar > click 'Control Center'
3. Click the cog wheel
4. Go to the 'Hardware' menu > then 'Boot Order'
5. Click 'Advanced...'
6. Paste the following line:

video.untrimmed_dynamic_cbuffers=1

Quit the settings and start Windows, the game should now work properly.

 

I had the same issue with Core Keeper on my M2 Max. The lighting was completely off, especially the torches. I tried adding the boot flag video.untrimmed_dynamic_cbuffers=1 as suggested by AlexR35, and it worked like a charm. No more lighting glitches, and the game is now fully playable. Just make sure to shut down the VM completely before making the change. This fix has been a lifesaver for me.

 

I had similar rendering issues running certain games through Parallels on my M2. The lighting bugs usually come down to DirectX translation -- Parallels uses its own graphics layer and some games (especially those using specific shader effects for dynamic lighting like torches) don't play nice with it.

A few things worth trying:

1. In Parallels, go to Configure → Hardware → Graphics and try switching between "Automatic" and dedicated memory allocation. Bump video memory to max (usually 2GB).
2. Enable/disable "Advanced 3D rendering" -- sometimes toggling this fixes shader issues.
3. In Core Keeper itself, try forcing DirectX 11 mode if it's defaulting to DX12 (launch options in Steam: -force-d3d11).
4. Lower the in-game lighting quality first, then bump it back up -- sometimes that resets the shader cache.

Honestly though, Parallels is hit-or-miss for games with custom lighting systems. Whisky (free, uses Apple's Game Porting Toolkit) or CrossOver often handle 2D/pixel games better than Parallels does. Might be worth trying Core Keeper through one of those instead.