Realistic mode

Topics related to Spacebuild in general should go here!
Realistic mode

Post#1 »Fri Feb 03, 2017 2:12 pm

Unfortunately a session timeout swallowed my very thorough first draft of this post, so my rewrite here will be somewhat more brief.

A few Spacebuilders have independently come to the conclusion that a realistic mode would be pretty cool. There's been a small amount of discussion about what "realistic" actually entails and of course some ideas have been thrown away. KSP and Children Of A Dead Earth collectively cover the hardcore simulator market pretty well, and Spacebuild has had its niche for at least 8 years that I can remember, so nobody should think I'm talking about huge transformative changes to it. Don't get me wrong, Keplerian orbital mechanics would be pretty cool, but that's not what this is about.

Anyway. The way I figure it, the easy things to make more realistic in Spacebuild are thrusters, resource storage, and resource generation. In the real world we've figured out underlying formulae that can describe just about everything a Spacebuilder is likely to want to do, so we can lean on Wikipedia and Project Rho for a lot of the maths.

Resources in Spacebuild are... Well, not entirely consistent with reality. I think densities became somewhat realistic a while ago which is a start, but I don't think 2 units of hydrogen + 1 unit of oxygen produces 1 unit of water with the same mass and using the correct amount of energy.

Converting all Spacebuild units to use SI-standard units based on mass should pretty much instantly make a ton of other stuff suddenly easy as various real world processes can be simulated easily and accurately. The "amount" of a resource in a network would ideally be representative of either the mass or molecule count of that resource with a conversion made between the two where necessary. Conversion processes are easier to implement with numbers of molecules as that's what they act on, while storage caches and engines be easier to implement given mass directly. At a guess I'd say mass is probably easier on players as well, as it's just a more natural unit.

There are pros and cons to each, but whichever ends up being used we end up with pretty much the same effect. Implementing processes like the Sabatier reaction becomes a simple matter of taking CO2 + 4 H2 out of the network and outputting CH4 + 2 H2O + energy. Consistent units = consistent chemistry = happy nerds. It also makes life easier for thrusters. Speaking of which...

GMod thrusters are simply all kinds of wrong. They don't use any sort of resources and are exactly as powerful as you need them to be. This cannot stand. In reality, rockets are subject to conservation of momentum - in order to thrust forward they've got to throw some propellant rearward. At risk of accidentally giving a lecture on space flight, typically that propellant is accelerated by a chemical reaction (such as in a conventional rocket) or an electrical field (such as in an ion engine). Spacebuild thrusters (as a placeholder name I'm just gonna call them engines to distinguish them from GMod thrusters) should therefore need energy and propellant.

Learning how power and propellant mass flow (amount of propellant per second) relate to thrust and exhaust velocity I'll leave as an exercise to the reader, but TL;DR for a given input power, more thrust = less exhaust velocity.

This opens the door to new engine types - engines which don't use propellant but require an atmosphere to push against (a la real world propellors, jets, etc), engines which mirror real-world ion drives with efficient but slow propulsion, and engines which mirror real world chemical rockets, gulping down combustible resources to produce relatively large amounts of inefficient thrust. I can't see a reason there can't also be hybrid motors - along the lines of the Reaction Engines SABRE which can use both onboard resources and atmospheric air as propellant.

Not so much to say about this. We could likely implement a cryogenic tank, offering relatively high density storage of 'gases' by pretending to keep them in a liquid state - it would constantly draw power (to keep cool, though there's no need to actually model that), or vent off contents at a slow rate if unpowered to represent boil off.

Under these changes, players have to start caring more about what resources exist in what areas. Hydrogen is a brilliant fuel (when burned in oxygen it's the most powerful non-fluorine bipropellant available) but it can't simply be scooped out of the atmosphere, it generally has to be generated by cracking water which is a highly energy-intensive process. Stock Spacebuild obviates that problem by making fusion power trivial, but if fusion required fuel which was only easily extracted on the moon...

Anyway I'm 75 minutes over my lunch break at work so I should probably get back to it. Any thoughts or questions or anything, gimme a shout. I am unfortunately not a rocket scientist or aerospace engineer but I do know a lot about the mechanics which would be at work in a more realistic Spacebuild and more importantly I know where to look for things I don't know, so if there are any queries about how physics can answer a particular question I'll do what I can to answer.

I will also need feedback from anyone who understands Spacebuild's internal organs or GMod modding - I don't know what information is really needed to start fleshing these concepts out a bit but I am a developer so given some requirements I can hopefully help figure this out.


Re: Realistic mode

Post#2 »Fri Feb 03, 2017 2:20 pm

Notes for myself - things I need to revisit and describe further as they're useful components for Spacebuild:

Water-gas shift reaction converts CO + H2O ⇌ CO2 + H2

User avatar

Re: Realistic mode

Post#3 »Sat Feb 04, 2017 12:45 am

I believe the SI-system is already being carried out in sb4. Many of these points should be pretty easy to implement and I'm looking forward to see some of these in the vanilla gamemode.


Re: Realistic mode

Post#4 »Sat Mar 18, 2017 1:55 pm

Hello, first of all let me give you a good advice: before posting any post to any forum learn to ALWAYS press ctrl+a, ctrl+c :)
That way you are safe from session timeouts, connection interruptions and bad forum coding.

To address your ideas: that is a really nice dreaming. I totally share many of these ideas, BUT unfortunatelly every time I tried to materialize some spacebuild ideas in Gmod, I was struggling with many unrelated things which often ruined the immersion feeling a lot :( Main thing to make spacebuild more realistic and enjoyable for me would NOT to make some units or chemical reactions be accurate and based on real science, BUT to provide some easy and always working tools to make anything more complex then two props ship fly without constant frustration and stupid problems of all kinds! :( Unfortunatelly it is really unrealistic that you need to change weight of certain props not to have some other props wave around like crazy. That you need to remember to unparent and reweld gyropod, pod controller and chair otherwise it does not fly at all or you end up somewhere in space when you exit the vehicle. That you fly somewhere and suddenly hit the invisible edge of the universe. There is simply always so many problems to overcome before you get to any enjoyment of actual spacebuild that the patience needed is simply too high :-\

Who is online

Users browsing this forum: No registered users and 1 guest