2160p/4k?

[OrsonDeWitt]

Hello everyone,
I was wondering if there is any reason not to use the biggest possible resolution as default (apart from bigger assets)? I assume that no matter the size, renpy will resize it neatly for all the smaller screens, right? Or is there anything to keep in mind here? Thank you!

[Imperf3kt]

Several reasons.
Performance, compatibility, battery life for mobile devices, output file size of the build, scaling (as large images are scaled smaller, a lot of the detail is crushed out of the image or blurred beyond recognition)

Larger images don't always mean higher quality artwork either. A lot of the time you can achieve an amazingly detailed looking game, with less than HD resolution artwork.
Everyone thinks bigger is better, but that's a misconception. Bigger can be better, but it doesn't automatically make things better just because it's bigger.

You can change this for your project if you want, but I think the defaults are suitable for the majority of users.

[OrsonDeWitt]

Several reasons.
Performance, compatibility, battery life for mobile devices, output file size of the build, scaling (as large images are scaled smaller, a lot of the detail is crushed out of the image or blurred beyond recognition)

Larger images don't always mean higher quality artwork either. A lot of the time you can achieve an amazingly detailed looking game, with less than HD resolution artwork.
Everyone thinks bigger is better, but that's a misconception. Bigger can be better, but it doesn't automatically make things better just because it's bigger.

You can change this for your project if you want, but I think the defaults are suitable for the majority of users.

I'm not sure I understand why you are mentioning performance — if I don't have a 4k monitor the game will be played in 1080p, so that will not affect performance as the assets won't be rendered in 4k either, or?
Compatibility — what do you mean by that?
Re: battery life, I am not releasing my game on mobile phones. Output file size is not a concern either.
Now about scaling. Usually when things are scaled down they look exactly as they'd do on a bigger screen, it's the scaling up that is the problem, isn't it? Are you saying that renpy is bad at scaling down, too? Is there any way to make different assets for different screens, like it's possible in CSS?

[Ocelot]

I'm not sure I understand why you are mentioning performance — if I don't have a 4k monitor the game will be played in 1080p, so that will not affect performance as the assets won't be rendered in 4k either, or?

Screen will be rendered in original resolution and scaled down before displaying. There is no other way, since you can access screen pixel-by-pixel from within game.

Now about scaling. Usually when things are scaled down they look exactly as they'd do on a bigger screen, it's the scaling up that is the problem, isn't it? Are you saying that renpy is bad at scaling down, too? Is there any way to make different assets for different screens, like it's possible in CSS?

Scaling down often introduces moire patterns: https://en.wikipedia.org/wiki/Aliasing (check images on the right)

[OrsonDeWitt]

Scaling down often introduces moire patterns: https://en.wikipedia.org/wiki/Aliasing (check images on the right)

Surely I'm not the only one who has pondered about screen sizes. I want it to look perfect both on 1440p and 720p. How do I achieve that? Is there some kind of CSS-style definition for different screen sizes?

[Zetsubou]

Surely I'm not the only one who has pondered about screen sizes. I want it to look perfect both on 1440p and 720p. How do I achieve that? Is there some kind of CSS-style definition for different screen sizes?

Renpy's Patreon article for October 2022 mentions the addition of image oversampling, which would let you do this.
You'd make your game in 720p, then also provide 1440p images to be used if the person is playing at a higher resolution, and Renpy would use whichever is appropriate.
But I don't believe that's been released or documented yet. I can only find mention of it in that patreon article.

Another option would be creating your own screen resolution preference and defining your images and screens based on that preference.
That's not automatic though. The player would be changing the config themself manually, and you'd need to do a bunch of extra coding.