Can UI layout or input offset issues occur in a 16:9-only Unity PC game?

[supple notch]

Can UI layout or input offset issues occur in a 16:9-only Unity PC game?
I am developing a PC-only indie game in Unity.

-The game will support only a 16:9 aspect ratio
-All UI uses Canvas Scaler (Scale With Screen Size)
-Canvases are a mix of Screen Space – Overlay and Screen Space – Camera
-The game supports Windowed, Exclusive Fullscreen, and Borderless Windowed modes

Given this setup, can UI layout issues, input offset issues, or screen stretching problems occur on different PCs or monitor setups?
Or is this configuration generally safe if the reference resolution and aspect ratio are fixed to 16:9?

[maiden maple]

Not really
But it seems like a bigger issue that your game only supports 16:9 than potential UI issues in other aspect ratios

It depends on how you plan to enforce the aspect ratio
If by stretching, then stretching will ensue

[supple notch]

Thank you for your reply.

Any part that exceeds 16:9 will be displayed in black.
I understand what it means, but I decided to make it this way.
Considering my current development capacity and workload, supporting other resolutions is not feasible for me right now.
If I have more development capacity in the future, I will revisit and revise it then.

[maiden maple]

To support other resolutions you only really need to define anchor points for UI objects and configure UI scaling
Unity itself adapts to any user's screen resolution unless you do extra work to prevent it

[supple notch]

The Canvas Scaler is currently set to 16:9.
If we want to support other resolutions, we would probably need to use different options.
In that case, wouldn’t pixel-level adjustments cause significant differences?

I also assume there are many other issues that could arise—things I’m not fully aware of yet.

And honestly, in many cases, isn’t 16:9 sufficient? (In Indie game)
Monitors with ratios that don’t fit 16:9 would mainly be 4:3 or ultrawide screens, and I believe those users are relatively few.
As for 16:10, the difference is small enough that I think it can be reasonably accommodated.

[maiden maple]

What would "pixel-level adjustments" practically be?

[supple notch]

I haven't tested it in detail, but wouldn't the distance vary depending on the pixel situation even within the same resolution? I'd rather maintain a full screen at least within a 16:9 resolution. I don't have the capacity to support all resolutions and screen sizes.

[maiden maple]

What "pixel situation"?

[supple notch]

The English translator is bad.
What I want is for the UI elements and text sizes to be the same across the entire screen.
It's difficult to support all monitor sizes and resolutions.

We plan to support only 1280x720, 1920x1080, and 2560x1440.

[maiden maple]

"Supporting" resolutions is not hard, you just need to configure how to scale the Canvas, and where UI objects are anchored to

Canvas Scaler has options whether UI is scaled relative to screen, physical size or pixels

Depending on your definition of sizes to "be the same"

Probably you want scale with screen size though
Then define matching width or height

Then set Anchors for UI objects
https://docs.unity3d.com/Packages/com.unity.ugui@1.0/manual/UIBasicLayout.html#anchors

Generally simply anchoring them to nearest corner of screen

This will require an hour or two of learning what scaling and anchors mean and how to use them
But it's worth the effort
Beats restricting your players out of their native screen resolution

If you don't want to bother with anchors, you can set the whole UI to just stretch to fit any screen size or shape
It will not look pretty, but it will not cause input issues or other issues really

Also, you don't need to support every screen resolution fully with your UI scaling

[supple notch]

Well, I'll use anchors. But before I even talk about the "ratio change" issue, I want all text to be positioned perfectly the same across various 16:9 screen sizes. Are there any examples of this? I think Scale With Screen Size provides that (but it doesn't support other resolutions).

[maiden maple]

It depends what you mean by positioned "perfectly same"
Positioned relative to what?

[supple notch]

ok wait a s

[maiden maple]

As long as your UI scales okay to typical landscape screens which are very similar in proportions and optionally 4:3, you'll be fine
If it doesn't work well with phones or monitors in portrait mode I don't think anyone will blame you

[supple notch]

As I mentioned earlier, I'd like to address the resolution change first, not the aspect ratio change. For example, 19201080 -> 1280720.

I want something like this image.

[maiden maple]

Canvas Scaler in Scale With Screen Size mode automatically handles that case

[supple notch]

Hmm, ok. I've found that the current settings work fine for most situations without any modifications. However, I'll eventually need to test the results at multiple resolutions. What resolutions are most commonly used and what would be best to prepare?

4:3 16:10 16:9 21:9 Should we just test this much?

[maiden maple]

Sure

21:9 is so wide I might not expect it to work perfectly without also implementing user-customizable UI
But as long as the game can be played on it, I would not worry

[supple notch]

Hmm, the 4:3 ratio actually feels like a significant change.
There's a lot to consider here.

Anyway, I'll try to support multiple resolutions as you suggested.