What about the FovAngleDegrees=90.000000 setting inside "Default.ini"?
This setting found under [Editor.EditorEngine] is for the Unreal Editor. It is present in all UE-based titles but never affects the game itself.
This is IEEE encoding: 00 00 AA 42 is the hex representation of the 32-bit single-precision float 85.0.
So, if you want to use a FOV larger than 128, you probably need to use the IEEE encoding. For example, for a 150.0-degree FOV, try changing 00 00 AA 42 to 00 00 16 43. For 180.0 degrees, use 00 00 34 43.
(I haven't actually tested this, but in theory it should work...)
Although proper multi-mon gameplay requires way higher values than these, daremo was right! :cheers Huge thanks to him for pointing me to the right direction.
A couple more tips...
Deux Ex Widescreen Utility:
http://forums.anandtech.com/showthread.php?t=2088245
Handy tool to instantly adjust the resolution, gameplay FOV and UI scale - but only supports 16:10 and 16:9.
Resolution constantly reset in user.ini:
First run the game and select a 4x4 digit res from the video options menu, i.e 1600x1200 or 1280x1024. Then you can edit user.ini and your new resolution will stick.
Updated sections of the DR follow.
==Cut-scenes==
Intro & ending FMVs stretch. (The bink files are 4:3 videos including letterboxing; without the black bars the intro is a ~17:9 movie whereas the endings are 16:10.)
4:3 (1280x960)
16:10 (1440x900)
16:9 (1600x900)
Real-time cutscenes and dialog scenes are Vert- in widescreen. This may be fixable by editing the [ConversationCamera] settings of Default.ini, but I'm not sure what changes to make. See Surround section for more details.
4:3 (1280x960)
16:10 (1440x900)
16:9 (1600x900)
==Surround Gaming Support==
Same method. The FOV formula is obviously not the same as for widescreen, though but here are "good enough" values for my native res...
1) Resolution
DocumentsDeus Ex - Invisible Waruser.ini
FullscreenViewportY=1050
FullscreenViewportX=5040
2) FOV
Program FilesDeus Ex Invisible WarSystemEngine.d2u
Replace all 3 instances of 00 00 AA 42 with 00 00 9A 43 (equivalent to decimal FOV 308)
3) UI
Program FilesDeus Ex Invisible WarSystemDefault.ini
fov__d=21 (scale of the "wheel" interface)
AssumedUIScreenWidth__d=1680 (your single-screen width)
AssumedUIScreenHeight__d=480 (default height)
(AssumedUI only affects font sizes and subsequently vertical position of text paragraphs. Dialog choices and incoming messages are always displayed on the left-hand screen, but at least all texts look fine with this setting.)
4:3, default:
FOV 85 (00 00 AA 42), fov__d=67, AssumedUI 640x480
48:10,
FOV 308 (00 00 9A 43), fov__d=21, AssumedUI 1680x480
FMVs stretch. Obviously, cropping them as explained by the OP won't help.
Real-time cut-scenes are Hor+...
...with lots of strange camera angles.
4:3, default ConversationCamera
48:10, default ConversationCamera
You can fix some of these by editing the [ConversationCamera] settings in Default.ini. I don't know exactly how, but dividing all
Angle and
Dist values by two is much better already.
Code:
[ConversationCamera]
SlightAngle=7.5
AboveAngle=30.0
ShoulderAngle=7.5
ShoulderMult=0.7
HeadMult=0.25
FaceScalar=0.38
SideTightDist=1.0
SideMidDist=1.5
SideAboveDist=1.0
SideAbove45Dist=1.0
ShouldersLeftDist=1.0
ShouldersRightDist=1.0
HeadTightDist=1.2
HeadMidDist=2.75
HeadLeftDist=1.2
HeadRightDist=1.2
HeadSlightLeftDist=1.2
HeadSlightRightDist=1.2
StraightAboveDist=1.16
48:10, "fixed" ConversationCamera