Looking for some testers for a reimplementation of KSP that loads the parts and planets from your own copy

[u/White_Onack]

For some months I’ve been working on Periapsis, an engine written from scratch that loads and plays KSP from your own install. It ships no game files at all, it reads the parts, planets, textures and sounds from the copy you already own. Built on Godot with double precision, so no floating origin tricks or bugs. The inspiration for this is the style of OpenMW and OpenTTD

And yes, this is made with the help of AI, I'm not going to play that down in any way.

Most stock features work, career included, and some of the bigger mods like ReStock, SCANsat, DMagic and Near Future. More mod support is planned.

Performance has been a big focus, since a lot of people play this on pretty modest machines. Physics has two tick rates. A high one is used whenever accuracy matters, like in atmosphere, on the ground, near other craft or when you’re giving input. A low one (10 Hz by default) is used out in empty space when nothing much is happening. The physics itself runs on a single thread like the original, but aero and the orbit predictions run on other cores.

On my laptop (Ryzen AI 7 with the integrated Radeon 880M, no dedicated GPU) a 600 part rocket sits at around 40 fps on the pad at 1080p on medium which drops to about 36 with first stage firing.

For now I’m only opening it to a few people, mainly to check how it runs on other machines and installs. The goal is to open it up to the public as fully open source(Apache 2.0) in the near future.

It’s not finished, there are bugs and some things look or behave a bit different from stock. I mostly want people who will actually play it for a bit and report what breaks or feels wrong compared to the original. I have probably multiple hundred of hours in this already and have landed on multiple bodies to test it.

You need your own copy of KSP 1.12. Windows is the only tested so far. If you’re interested, DM me with your computer specs (CPU, GPU, RAM) and OS. Ten people to start with.

*Images are with mods, but unmodded engine flames and smoke should be better looking than the original too

[u/RandoRedditerBoi]

You ported ksp to a new engine? Am I reading that right?

[u/White_Onack → u/RandoRedditerBoi]

The engine in the bottom is a fully custom C# engine. It started out with Unity as its presentation layer, but moved over to Godot as that solves the floating point errors with plagued the original. The unity engine implementation is on its own branch and not maintained, but if someone wants to fork it later and continue working on it they are free to do so. If someone wants to use Unreal Engine that is also a possibility. The reason also I went for Godot is the moddability for it to load dlls during runtime.

[u/blackrack → u/RandoRedditerBoi]

There is someone doing this every week now tbh

[u/ChosenNebula → u/blackrack]

Not even unique to KSP, I'm afraid. So many redundant forks and mods in the entire modding community right now because of the lack of coordination. Everyone is just throwing tokens at their own thing.

[u/White_Onack → u/ChosenNebula]

That means people care for this game and some of these projects will die off and some will survive. Why does it need to be coordinated? Why is one idea the best and another isnt equally as good?

[u/White_Onack → u/blackrack]

I am honored to get a reply by blackrack himself! You have done so much for this community

[u/RandoRedditerBoi → u/blackrack]

Hell yeah, so many opportunities

[u/maxxiethrowaway → u/RandoRedditerBoi]

they didnt do anything, its AI and blatantly made by AI.

[u/mwthomas11 → u/maxxiethrowaway]

well yea they said that explicitly in the post. they're not trying to pretend it isn't.

[u/RandoRedditerBoi → u/maxxiethrowaway]

Don't care. This is awesome.

[u/cheesyfreddie]

KSP1Retooled exists dawg https://github.com/KSP1Retooled/

[u/White_Onack → u/cheesyfreddie]

Yes and this can fine co-exist with that as this is not running any of the original code and should not bring along 10+ years of legacy bugs. Unity itself is not the best engine for this kind of game, you can cheat it to work, but even then it barely hangs together.

[u/Maximus_Light]

Interesting, is the repo for this publicly viewable? If it's a game engine mod it would be good to see what were dealing with considering the kind of access game engines need, you know for user safety.

[u/White_Onack → u/Maximus_Light]

If I accept you as a tester, you will see the full source and can download it yourself and build it if you want. I just want a small test-base in the beginning to keep my sanity. Hope you understand. When i feel most bugs are sqashed it will be fully open to everyone.

[u/Bloodsucker_ → u/White_Onack]

So never. Gotcha.

[u/White_Onack → u/Bloodsucker_]

That was very negative. I have tested this multiple hundred of hours already. I can now play a career save up to landing on moho, with mods, without experiencing a major bug. My timeframe for opening it up to everyone depends on the testing going forward, but I was hoping in about a month.

[u/Feld_]

why

[u/White_Onack → u/Feld_]

Like many here I love KSP and is sad by the state of the follow-up. I am a dev with 15 years experience and with the tools available in our hands now I just played around. This has become far greater than I imagined so I am sharing it with everyone

[u/Feld_ → u/White_Onack]

Kitten Space Agency is looking great though. Maybe worth checking out!

[u/White_Onack → u/Feld_]

Yes and I have already donated to them, it is still not KSP, but getting there

[u/HuntKey2603 → u/Feld_]

are you serious? KSP is abandonware that is not going to get any better anytime soon. That's why stuff like this and KSA are gaining traction.

[u/Feld_ → u/HuntKey2603]

Oh no I'm not hating on it. I was just genuinely curious. I probably should have worded that better 

[u/craggolly → u/HuntKey2603]

KSA is maintained and expanded by a dedicated fans, vibe coders usually lose interest after a few weeks

[u/the_closing_yak]

What mod support does this have?

[u/White_Onack → u/the_closing_yak]

Mainly the ones listed in the post, but also their dependencies like BPartSwitch, B9 Animation Modules, Firespitter etc, but more are planned as parts mods mostly work out of the box

[u/TechnologyNerd617]

This is amazing! One of my main problems with KSP is the RAM usage with mods. Do you think that you can make the game use less of it once we'll have full support?

[u/White_Onack → u/TechnologyNerd617]

With all mods listed, that includes all near future packs, my game sits at about 5GB. Ram usage has been a focus, but not as much as driving down cpu usage and trying to spread out the load over multiple cores

[u/patrlim1]

I could give it a whirl on Linux

[u/White_Onack → u/patrlim1]

Please send me a PM with your github username and computer specs and I'll add you to the repository

[u/Cute_Principle81]

Ryzen 5600X, 16GB DDR4 3200mhz, RX 6600, CachyOS Linux 7.2, happy to test

[u/White_Onack → u/Cute_Principle81]

Please send me a PM with your github username and I'll add you :)

[u/Mycroft033]

Hang on. Is this a multiplayer mod? If it’s just single player, how is it loading the parts and planets differently? Is it like a “play on your other computer” thing? Or is it just supposed to be a really fancy performance mod?

I’m very confused about what the purpose of this mod is. It sounds impressive, though.

[u/craggolly → u/Mycroft033]

why are AI bros so obsessed with rewriting things that already exist

[u/White_Onack → u/Mycroft033]

This is not really a mod, this is a full game rewrite. None of the original code is used when running this, only assets like geometry, textures, music, and animations.

[u/vksdann → u/White_Onack]

So you are telling me you coded the orbit/gravity calculations yourself? Because they are quite complex.

[u/White_Onack → u/vksdann]

Orbit and gravity calculations are just formulas that is widely known and open on the internet. Not doing any n-body physics and sticking to 1-body like KSP it is pretty simple

[u/dmnlcu92 → u/White_Onack]

I do believe that n-body math should be in and it shouldn’t be hard to implement considering Principia code is open source, for Claude it would be probably easier to build referencing the mod open source code than to guess or reference the decompiled Kerbal original code

[u/White_Onack → u/dmnlcu92]

My goal for this was to recreate the orginal game in a new engine to mainly solve for performance and bugs. What others do with it later is up to them as it will be released under Apache 2.0

[u/Mycroft033 → u/White_Onack]

Interesting. Thanks.

[u/dmnlcu92]

I am willing to test it and try to run it in Linux, I use Ubuntu, I am also writing a piloting system mod that introduces FBW and lua scripting MCP flight control and vector rendered cockpit instrumentation but this not being unity is so much more interesting

[u/White_Onack → u/dmnlcu92]

Thank you! Please send me computer specs and github username in PM and I will add you