I ran into a strange issue with DOOM 3’s customizable screen resolution and aspect ratio. It had previously been setup for a resolution of 1440×900 (16:10 ratio) but, somewhere along the way, every time the game started up it switched into 640×480. Strangely, this could be set to 1024×768 from inside the game but the DoomConfig.cfg file didn’t seem to reflect this change – still listing resolution as 1440×900.
After a bit of digging on the web, it turns out the “r_mode” switch needs to be set to -1 for the two custom resolution variables (r_customHeight and r_customWidth) to actually be read – otherwise the settings are ignored. In my config, for example, it was set to 5 (which turned out to be 1024×768) which had the effect of ignoring the custom settings I was entering. Changing it to -1 allowed the custom settings to take effect. An example configuration snippet is given below:
- seta r_customHeight "800"
- seta r_customWidth "1280"
- seta r_aspectratio "2"
- seta r_fullscreen "0"
- seta r_mode "-1"
Note: setting r_fullscreen to 0 will cause the game to start in a window – set it to 1 for fullscreen. The three options available for r_aspectratio are: 0 (4:3), 1 (16:9) and 2 (16:10).
These lines will need to be added to the config file of any mods you use as well – for example, ClassicDoom 3 uses cdoom/DoomConfig.cfg underneath your Doom 3 settings directory.