Sunday, February 11, 2018

Those Ultrawide Monitors

You might have seen ads or reviews for them...ultrawide monitors with an aspect ratio of 21:9.  These are touted as being superior in some ways to a multi-monitor setup.  For one thing, there are no monitor bezels breaking up the scene.  And some of them are curved, to produce a more "immersive" experience.

Dual Monitor Set-up
Ultrawide Curved Monitor
I recently got one of these puppies...a Dell 38" Ultrasharp monitor.  It's big, and it's lovely.  It has about 3/4 of the actual screen real estate of my previous 27" dual monitor set-up, and it's the same screen height and pixel size as the 27" monitors.  I don't miss the small piece of real estate that I gave up, because it was outside my peripheral vision anyway, whereas I can see ALL of the 38" monitor.  The curved screen does not appear to introduce any distortion, and it does make for a bit more of an immersive effect.  Not only that, but I get a lot more effective screen real estate in SL, because I always kept SL on my primary monitor only...both because of the bezels, and because SL can produce some strange glitches when you try to extend it onto a second monitor.

But, I have to tell you, gentle readers, that there is one big gotcha that none of the reviewers seem to mention.  A lot of games, including Second Life, have a built-in edge distortion.  That is, things at the edges of your screen are stretched horizontally, at any aspect ratio other than 1:1, a square image.  You can actually see this on your regular old 16:9 monitor, although I had never been bothered by it before.

But on the ultrawide monitor, it's much more apparent.  Circles become definite ovals if they're off to either side of the screen. as shown by the screenshot below.  All of those prims are identical spheres!
I tried looking at SL using different resolutions and aspect ratios.  While a less-wide image shows less edge distortion, it is still present...and it's present, also, on "regular" monitors.  UI windows and buttons,menu bars and HUD controls on the screen are not affected.  It's only the view of the Second Life world itself that's distorted.  It's not the ultrawide monitor that is to blame, it's the design of the SL viewer itself...and other similar games that exhibit the same distortion.

It's time to write to your viewer developers and tell them it's time they took a...wider view.


  1. What would be a solution, though? Those elongated spheres are the correct projection of a sphere onto a plane from an oblique angle. You'll see the same thing on an ordinary-sized monitor if you turn up the SL camera's view angle. The apparent distortion comes from viewing the screen from further away than the camera was from the scene.

    You could reduce the camera field of view and send the camera correspondingly far back from your avatar, but that would raise other problems, like not being able to have your camera in the same room as you indoors. Moving the near clipping plane close to your avatar might help with that, but I don't see a debug setting to adjust that.

    The curvature for the screen will accentuate the apparent distortion, and in principle the viewer could compensate for that, if it knew the radius of curvature.

    1. Thank you, Tura. Good point about the camera position vs. the actual eye position. This is what the viewer needs to compensate. The monitor curvature has nothing to do with this distortion, though. That can be established simply by noting that nothing else on the screen is distorted...only the view of the Second Life world.