1. First you need Notepad++: https://notepad-plus-plus.org/downloads/
   
2. Second once installed you need to go to Plugins > Plugin Manager > select HEX-Editor and install it
   
3. Now navigate to your game files (Right click the game in steam > Properties > Local Files > Browse Local Files)
   
4. Right-click on UnityPlayer.dll > select Copy > Paste this file in the same window to create a backup
   
5. Right-click on the UnityPlayer.dll > open in Notepad++ (or drag it into the notepad++ window)
   
6. Click Plugins > HEX-Editor > View in HEX (if you fail later it is because you aren't in 8-bit mode, you can set this in the options for the plugin)
   
7. This next step is for 3440x1440 (2560x1080 will be at the end)
   
8. CTRL+F and click the Replace Tab
   
9. Paste "39 8E E3 3F" in the Find field and "8E E3 18 40" Replace field (Don't click anything yet, and you obviously do not include the quotation marks)
   
10. There are two values you need to replace, make sure you aren't replacing the one with a line-break.
    
11. Click FIND to find the entry (make sure your cursor is at the top) and replace it.
    
12. Now click Save and close Notepad++
    
13. Launch the game
    
14. Enjoy true 21:9 gameplay with no black bars

Special Thanks: Shout-out to Bodhsativa in the comments for helping update the guide with the new DLC changes. I no longer own an ultrawide so am not maintaining these guides if the game is patched.

NOTE: For 2560x1080 use "26 B4 17 40" as the new value instead.

NOTE: This is just the concept for finding FOV and modifying it. I have no interest in troubleshooting this or determining what works and does not. Use this guide at your own risk. For understanding how to modify the below and what, refer to the other page in this guide.

FOV for games can be found in hex in one of the game's files (probably xgcore.dll like the resolution). Format will most likely be in IEEE 754 which is comprised of four hex pairs (just like resolution in this game and most games).

• Example: An FOV of 60.0 would be "42 70 00 00" in hex.

Typically this is formatted from right to left game files. So "42 70 00 00" becomes "00 00 70 42" in hex.

You can use a IEEE 754 calculator to get your fov value into hex (ex http://babbage.cs.qc.cuny.edu/IEEE-754.old/Decimal.html ). Paste your fov in the decimal field and click the Rounded or Not Rounded button (either works) and look for the hex result under single precision field.

• Example: Instead of hex in this format "ST UV WX YZ" it would be in this format "YZ WX UV ST"

In anticipation of requests for odd/unusual aspect rations I have included a list of common ones below:

Since someone asked and apparently can't use a decimal to HEX calculator I'll add in a simple table for common resolutions: