[1.1.0 (1-30-19)]
After over 5 years since release, NightGFX has finally received an update! This new release brings a major change by decreasing the level of darkness by 15%, making it much more bearable to play with while still giving a night-time feel. I also added the one missing sprite that OpenTTD has been complaining about for the last 4 years or so, making it finally "up-to-date", although I haven't (yet) included the 2x zoom GUI sprites found in standard OpenGFX. Other than that the set is basically still the same, so no big changes to the lighting effects yet, although I still would like to at some point, along with a few other ideas I have.
See below for the comparison pics, and as before the set can only be downloaded via the online content. Enjoy

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Welcome to my latest "just for fun" project.

Inspired by those awesome mock-up screenshots and the decade-old night conversion by Andrex, I decided to breathe new life into the idea of a "night mode" in TTD. It's basically just a night version of OpenGFX, but by utilizing 32bpp capabilities I was able to break away from the restrictions of the TTD palette to get what I feel is a more realistic and 'clean' darkness compared to the old attempt. More importantly, this new implementation allows company colors and other recolor masks to work properly, something the old set simply couldn't do because of the palette.
I've also opted to build this as a base graphics set rather than a NewGRF, which allows you to switch freely between day and night by changing between NightGFX and OpenGFX in the main menu (or, optionally, forcing and unforcing the 8bpp palette by editing the openttd.cfg file, but that's a lot more work

Which brings me to the one major problem with this set; you can't use any NewGRFs if you want to be able to switch from day to night.


So, taking that into consideration, NightGFX is effectively a standalone set, unless someone creates some night grfs and you don't mind always playing in the dark.

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Due to it being 32bpp, NightGFX is only compatible with OpenTTD 1.2.0 or newer. It is too big to upload to the forums so you will have to download it in-game or via the Bananas site. It is of course released under the GPLv2, and you can obtain the source here. There is also a simple guide I wrote up on how to make compatible graphics if you're interested in that. I'll post the guide separately later.
Please playtest it and tell me what you think, particularly about the level of darkness and the lighting effects, or if you encounter any glitches. Enjoy!

P.S. I'm not very good with screenshots, so if you have some better ones, post them!
For those of you who don't have any active NewGRF-less maps to play around with, I've attached one of my own so you can at least see it in action: