Gordon Freeman Makes Me Nauseous

Black Mesa, Half-Life 2, and Motion Sickness

The first couple of times I tried to play Black Mesa I ended up quitting about 45 minutes into my session. It's not because of a dislike for the game; from what I've seen, the recently-released mod is a fun and relatively faithful remake of the original Half-Life. My main issue with Black Mesa is the fact that I start feeling queasy and need to stop playing after 45 minutes to an hour of gameplay.

A quick Google search reveals that I'm not alone in my plight (Steam forums: link, link). It seems like motion sickness issues are pretty prevalent with Valve's Half-Life 2, as a Google search for "half life 2 motion sickness" turns up 660,000 results.

HL2 is pretty much the only game that has given me trouble in my long and storied gaming career. Throughout the last 15 or so years I've played titles from just about every FPS series imaginable, from Quake and Unreal Tournament to Battlefield and Call of Duty. None of these have caused me to feel even a hint of unease, yet HL2 does me in within an hour. What's odd is that I've never had a problem with other Source games like LFD2, TF2, or Portal. I can play CounterStrike: Source, released within a couple of weeks of HL2 and using the same Source engine, for hours on end with zero discomfort.

Various FOV values in Black Mesa. From top to bottom: 75, 90, 105.

The Fix?

"Change your FOV."

Aside from obvious tweaks like disabling motion blur, head bobbing, and view roll, that's the bit of advice I see the most in regards to this issue. Valve's developer wiki weighs in with the following:

Motion sickness: Smaller FOVs tend to exaggerate camera movement, whilst larger FOVs tend to minimise its effect on the image. Thus setting a wider FOV can sometimes help to reduce motion sickness during gameplay. If you are experiencing such problems in Half-Life 2, try changing the FOV to 90 using the command "sv_cheats 1;fov 90" in the console.

Perspective distortion: Wider FOVs introduce more perspective distortion into a image, whereas small FOVs tend to flatten perspective. The distortion is caused by projecting (spherical) optical geometry onto a flat screen - that's why IMAX Dome screens are curved. Like all optical artifacts, perspective distortion is much more noticeable in still images than in the moving images of FPS gameplay. For making more cinematic screenshots, use a smaller FOV and a larger camera-object distance.

There's a slider in the Black Mesa options that lets you change the FOV (field of view) to any value between 75 and 90 degrees. In addition, by using the in-game console or editing the config.cfg file (located in Steam\steamapps\sourcemods\BMS\cfg), the user can assign values outside of the standard 75-90 range via the "sv_cheats 1" and "fov #" commands, where "#" is the desired field of view. Thus far, an FOV setting of 110-ish seems to work best for me. I haven't put a lot of time into testing exact values, but I did play for 50 minutes without incident using an FOV of 110 degrees earlier today.

Looking around with an FOV value of 105. That's the same door viewed from the same spot.

Unfortunately, any FOV value on the higher end of the scale introduces a pretty funky fisheye effect that heavily distorts the edges of the screen. I've read comments from players who claim that the fisheye distortion actually makes things worse or that things like refresh rate or weapon sway are the real culprits. Whatever the case, this whole experience is pretty frustrating.

Half-Life 2 is universally hailed as one of the best PC games ever (arguably the best), and yet I've never finished the game due to this issue. Assuming I can actually get myself through Black Mesa, I'll definitely be paying another visit to City 17.

Hopefully Dramamine isn't required.