Let’s assume that we have no technical limitations - infinite memory, infinite CPU and GPU cycles. We can run as many viewports as we could possibly want. What else could be holding us back? Here are a few game design considerations that make split screen a non-trivial task, even in a scenario where technical limitations don’t exist.
When we are designing a game, screen visibility and aspect ratio are important. Look at this screenshot from God of War Ragnarok:
The framing of the cinematic is absolutely focused on showing the characters and their difference in size on screen, with the point of focus being Mjolnir in the very center. You can see at a glance how much bigger Thor is than Kratos. That’s completely intentional. Now let’s see it in split screen. First, let’s split the screen vertically:
I tried to retain the “gist” of the original shot. We’re still centered on Kratos vs Thor with Mjolnir in the center of the frame. I tried to keep as of both characters in frame as I could. Clearly, this shot doesn’t have anywhere near the visual impact of the original. You just can’t see much of either character. We retain the struggle in the center of the screen for Mjolnir, but we lose the visual representation of the characters’ sizes. Now let’s try splitting the screen horizontally instead:
Once again, I tried to fit as much into the frame as I could. Now we can’t see enough of either body, it’s so squashed down. We can’t see the relative size of Mjolnir either. We can’t even see how tall Thor is because his head is getting cut out of the frame.
It’s pretty obvious that this shot is meant to be viewed at a specific aspect ratio. Halving either dimension simply won’t work, significant rework must be done in order to do this. But what if we retain the original aspect ratio by dividing into fourths?
It’s better - we can at least see all of relative sizes of each other. But the characters themselves are much smaller, especially because we don’t sit close enough to the television in order to get the same effect. But let’s move on. There are other issues.
User Interface and Screen Size
Things get worse when we have to put UI on the screen too, because we can’t shrink our UI or text to ¼ of its original size in order to maintain the screen aspect ratio. Here’s another screenshot from God of War Ragnarok, this time with combat UI:
Let’s try splitting this screen vertically:
I’ve done a quick and dirty copy/paste job for the UI elements and maintained their relative size on screen. We’re already losing out on a lot of peripheral vision in combat. Since we can’t scale the UI, observe how it is taking up significantly more screen space too. We have to show two of every UI element, not one… and they can’t really be scaled down or they’ll be too small to see. Now let’s see it in horizontal split screen:
Now we have the peripheral vision… kind of… but the UI is still eating a lot of that screen space and we’re losing significant amounts of vertical screen space. This might be ok in a game where enemies show up to the left and right, but not if there are often enemies coming from above or below. The UI screen space problem gets significantly worse when we run it in four viewports while maintaining UI screen size:
Everything feels so much more squished and tiny, even when running at the same aspect ratio as the original. It’s a fundamentally different experience, because you’re seeing so much less of the world in the various split screen modes. God forbid we try to have any kind of subtitle display in four-way split screen.
These are two specific constraints with splitting the screen. There are more problems I haven’t gotten into, like directional audio no longer working because we’ve got multiple simultaneous player locations or handling menu navigation gracefully in split screen. This is not to say that it is impossible to make split screen work - it is absolutely not impossible. What I am saying is that it is not trivial to make it work - we can’t just turn on two/three/four viewports and call it a day, not without inadvertently causing a significantly worse player experience in many regards. These kind of challenges must be identified, designed for, and fit into the development budget.
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