Game resolution

[nyaatrap]

Crash issue will be fixed at the next release: https://github.com/renpy/renpy/issues/46
I didn't test it so I can't tell what would be the limit now. So I'm waiting the next release to decide what would be the best. If I get more spare RAM, I can add more animation effects I gave up on my game.

[Tempus]

I hope I'm not violating some necroposting rule by posting a month later, but I have things to add based on the research I've done for the VN I'm working on.

JPEG & PNG
I noticed a few misconceptions about these formats (JPEG, mostly) in this thread. Firstly the compression artifacts in JPEG images. These are unnoticeable provided one doesn't go overboard with compression. In Photoshop, I find the 'Quality 10' setting to be the last level of compression before even small amounts of artifacting can be discerned. As already stated, an image saved in a lossy format (such as JPEG) shouldn't be resaved in a lossy format due to generation loss. There are ways to resave JPEGs that don't cause this, but ideally one's workflow prevents this from being necessary.

Second, JPEG and PNG are good formats which outperform each other on specific types of images. JPEG, again as already noted, is good for photographs. However, that doesn't mean it's not good for other types of computer generated images. JPEG performs best saving images with gradients and smooth transitions between adjacent pixels. While the colours in the image below are still distinct from each other, they transition smoothly.



PNG performs best saving images where there is no bleeding / smoothing occurring between any of the different coloured pixels. In other words, images with mostly abrupt changes and solid colours are best for PNG. Therefore it can sometimes be more efficient (in regards to file size) to save using PNG even when no transparency is required as in the example image below.



Additionally, there's compression tools out there for both formats which can yield a further reduction in file size. Now, this might seem like a bit of a tangent given the thread is "game resolution", not "game file formats", but since some folk seem to have performance concerns regarding higher resolutions, I think this is relevant. Also, while PNG is a lossless format, there is a way to create lossy PNGs (with more options than Photoshop), though I haven't had any luck with it thus far since the programs available are either in Russian and spit errors at me, made for Mac or Linux, or use command lines (i.e., no GUI) which I'm not confident enough with... yet.

Supporting multiple resolutions & aspect ratios
As far as resolution itself goes, here's what I'm doing for the project I'm working on. I'm creating the BGs at 1920 x 1200 (16:10) and supporting any popular enough resolution below that. (I'm still not decided on whether to scale at runtime in Ren'Py [our tests so far seem fine and we already have a multiple resolution option for this] or to create different builds with different resolutions. After reading this thread I'm leaning toward the latter.) The resolution I've chosen covers the most amount of people possible with the best quality possible. On 16:9 screens, the 16:10 BGs are vertically centred with the extra height overflowing offscreen; a few lost pixels at the top and bottom won't be missed . This means if you have a 16:9 *or* a 16:10 display there will be no letterboxing.



We'll likely be supporting 800 x 600, but that resolution and aspect ratio will not be catered to. My position with the art is that it's better to let stuff overflow rather than distort the image by squishing it into an aspect ratio it wasn't made for, which just looks awful. Further, nothing will ever be zoomed past 100% for a similar reason. To those saying that it takes too long to resize assets I think I'd have to disagree. You can batch process a whole lot of images in Photoshop, though I'm sure there's other free programs out there that allow this.