Don't completely discard mass of physics-insignificant parts

[Jouni]

KSP is a game. Not a realistic simulator. Even games that go as far as being as realistic as they can be tone things down for the sake of gameplay and performance.

The fact that KSP is a game doesn't exclude striving for realism, even at the expense of those unwilling to spend the effort to learn its subtleties.

It's a widespread misconception that games should be fun, interesting, playable, or something similar. Games are a form of art, entertainment, and expression, and they can be used to express everything books, films, and paintings can, and probably much, much more. They can be educational tools, political commentaries, attempts to drive the players to commit suicide, blatant propaganda, means to resolve conflicts, foundations of a religion, and pretty much anything else you can imagine.

"It's a game" is probably one of the worst arguments ever, no matter what you're arguing for.

[xcorps]

If you want to strive for realism then why stop at adding mass to an insignificant part?

We should have to build the turbopumps for the fuel tanks, make sure they can achieve the design RPM and flow rating while maintaining the proper cooling with proper manifolds and valve redundancy, all while making sure that the materials used in the construction of the pumps can withstand the design pressures without causing the rocket to spin off course. No? But it's realistic...

And we should be setting off bombs in the combustion chambers. Which would actually be fun.

[cpast]

The fact that KSP is a game doesn't exclude striving for realism, even at the expense of those unwilling to spend the effort to learn its subtleties.

It's a widespread misconception that games should be fun, interesting, playable, or something similar. Games are a form of art, entertainment, and expression, and they can be used to express everything books, films, and paintings can, and probably much, much more. They can be educational tools, political commentaries, attempts to drive the players to commit suicide, blatant propaganda, means to resolve conflicts, foundations of a religion, and pretty much anything else you can imagine.

"It's a game" is probably one of the worst arguments ever, no matter what you're arguing for.

How's this? "KSP is a game, the primary purpose of which is to permit certain members of Squad (maybe all the devs, maybe some are only considered part-time) to do things like 'pay rent' and 'buy food'. In general, games which are enjoyable to play have been better at this sort of task; a game being realistic does not thus improve its ability to do this, unless it is hyper-realistic in enough aspects to be useful as an actual training simulator, or if the realism makes the game more enjoyable. Within the constraints of 'provide for basic sustenance', Squad has various priorities for the game, but their top priority is making the game enjoyable within the framework of a space simulator which tries to be generally realistic."

[Superfluous J]

If you want to strive for realism then why stop at adding mass to an insignificant part?

Two can reductio ad absurdum. You want massless parts? Why not make them ALL massless? Then you won't need to worry about dV at all.

[xcorps]

Two can reductio ad absurdum. You want massless parts? Why not make them ALL massless? Then you won't need to worry about dV at all.

LOL, but that's not realistic.

[KerrMü]

In my case, I love this game BECAUESE it is challanging. So being forced to deal more with ballancing issues would be a great thing IMO.

Sorry, But if you want to get a whole Spacestation into orbit in one piece, then:

a: you should be penalized (gameplaywise) for it, and it should be really hard and complicated

b: you are robbing yourself the challange, fun and difficulty to assemble it in space properly

For me, "massless" parts are a bit cheap, and at this point probably just a problem with the engine and performance, and will hopefully get fixed in the future.

[Vaporo]

Of course, now that I think about it, the suggestion of adding the mass of massless parts to the center of mass of mass of the parent part has been suggested so many times and is so obvious (to me) that you would think that the devs would have thought of it. Perhaps this whole discussion is moot because doing something like that would require such a deep rewrite of game code that it would be nearly impossible without taking up a whole update (which I'm sure it doesn't, though I'm just making a point).

Or, maybe the devs never planned to have massless parts, but they only thought of the idea at the last moment before the update, so all they gave us in the update was massless parts.

Edited June 21, 2014 by Vaporo

[Vindelle_Sunveam]

Bump from the depth of Hell :

I really think this suggestion should get *again* some visibility. It's been a while since I play KSP, and these last months, I've gotten into lightweight probes and have to say : balancing a goo cannister (0.015 + physics) with an Communotron (0.005t - physics), a thermometer (0.005t - physics) and an accelerometer (0.005t - physics) should be possible.

I think this is a great gameplay issue concerning this design niche.

Feel free to bury that back, as long as it triggers something for the future developpement of the game

[r4pt0r]

bumping again to suggest that OP's idea be called "physics significance=2" in config files.

[Red Iron Crown]

Also worth bumping due to more massive physicsless parts. The O-10 monoprop engine and Vernor LFO RCS thruster each mass close to 100kg but that mass is ignored by the physics engine.

[Artophwar]

Any engine, rcs thruster, fuel tank, solar panel, battery, ect should have mass at least added to the total mass of the ship. We should have to pay the cost and the dV for taking these parts into space as they can provide dV. The small science parts, ladders, some of the structual parts I am fine with being massless for gameplay reasons. As they are more aesthetic in use and less about getting the craft to wear it is going.

[Technical Ben]

I agree too. Massless parts stink! If the phisical model has to be simplified, why not ad the mass of those small attached parts to their "parent's" mass instead of eliminating the mass?

This is a great idea along with the above post too. A simple "fix" for both realism, gameplay and simplicity (easy implementation of the engine and low CPU use).

[Renegrade]

I'm definitely in with the "adding the mass to the massed part(s) of the ship". (I'd really love it if you could put things INSIDE various parts, like make a load out for a capsule, like oh, real life)

However, I'd ALSO like it to be clear regardless of whether or not this idea is picked up or not, that anything that IS massless/assigns it's mass elsewhere should read "Trivial" or "None" in the mass field, instead of "0.015" or whatever.

That way, we can know when massless shenanigans are going on.

[xcorps]

I agree.

Maybe go one step further and have them become a new part type. Say... Adjunct parts. You slap a battery onto a ship and it has no electric charge, mass, or whatever. All it does is add its listed features to the part you added it to.

Obviously some things (docking ports) cannot be adjunct parts. And adjunct parts should always be radially attached and have no ability to attach things to them. And I'm not sure how (or if) you could (or should) make things like solar panels into adjunct parts (the smallest one is currently massless, no?) but it'd simplify the UI a lot for sure. How much battery power do those 32 batteries have? Right click the orange tank you slapped them on.

I really like this. A lot.

[NWM]

I am waiting for the tiny first massless fuel tanks. I'll build a ship of 10000 parts, and it will fly smoothly to everywhere - delta-v: 100 000 m/s?

[pellinor]

I'd vote for adding the mass to the parent part, including a temporary shift of its CoM. The reason is I'd like to use those parts to balance my ships.

[UberFuber]

I'll add my small input.

I like the idea of adding "massless" part's mass to the parent body they're attach to. Shifting CoM can be abstracted out as that whatever added mass they're adding is balanced off by tweaks to the parent body in construction.

[LethalDose]

I am waiting for the tiny first massless fuel tanks. I'll build a ship of 10000 parts, and it will fly smoothly to everywhere - delta-v: 100 000 m/s?

I'm guessing the won't do this for obvious reasons.

I'll add my small input.

I like the idea of adding "massless" part's mass to the parent body they're attach to. Shifting CoM can be abstracted out as that whatever added mass they're adding is balanced off by tweaks to the parent body in construction.

I think this looks like a super-easy fix on the surface, but then I realized you could attach physics-less parts to other physics-less parts... You'd need someway to assign the part's mass to the nearest parent that has physics simulated. This isn't impossible, or even particularly difficult, but it is more complex. That complexity could actually slow down the game beyond what is being saved by making some parts physics-less, and could also increase instances of goofy behavior.

The more I think about this, the more I think I'm okay with some parts just not having physics simulated, as it is currently. It's an known exploit, and some players will abuse it, but its usually pretty obvious when they do.

[M3tal_Warrior]

Another suggestion (don't know if that's been made yet): Create a meta-part out of all massless parts on the CoM without hitbox, so mass is calculated correctly. This meta-part can be updated the moment one of its then sub-assemblies is being separated from the root tree and thus not longer part of the rocket. Should be easy to calculate, and keep the load on the CPU low.

[Superfluous J]

I like the idea of adding "massless" part's mass to the parent body they're attach to. Shifting CoM can be abstracted out as that whatever added mass they're adding is balanced off by tweaks to the parent body in construction.

I think this looks like a super-easy fix on the surface, but then I realized you could attach physics-less parts to other physics-less parts.

Not if you just don't let anything be massless except radially-attachable parts that themselves do not allow any attachments. This means everbody's favorite tiny little strut will have to have mass, but really if you're using enough of them to slow down the physics calculations, you're probably doing so to abuse the fact that they're currently massless

The more I think about this, the more I think I'm okay with some parts just not having physics simulated, as it is currently. It's an known exploit, and some players will abuse it, but its usually pretty obvious when they do.

Agreed. In the end, it doesn't make THAT much of a difference.

[rkman]

In the end, it doesn't make THAT much of a difference.

Massless parts can have a significant effect on delta-v and twr of any small craft, without deliberately trying to exploit.

In order to avoid accidental exploitation the player would need information that the game does not provide.

[Temeter]

Massless parts can have a significant effect on delta-v and twr of any small craft, without deliberately trying to exploit.

In order to avoid accidental exploitation the player would need information that the game does not provide.

But what meaning does accidental exploitation even have? Just see it as getting lucky. Technical advance and lucky developments and stuff.

Edited July 29, 2014 by Temeter

[Red Iron Crown]

At the very least the VAB/SPH should accurately report the masslessness of those parts. I mean, if we're expected to do delta-V and TWR calculations by hand (given the lack of a stock calculator) at least give us the correct values to use.

[EdFred]

u-u-d-d-l-r-l-r-b-a select start

No one is forcing you to use the above code, or any of these parts to build. I've never used a cubic strut in any builds until last night. And that was specifically in response to a Manley video about the new mono prop engine.

[Sky_walker]

But what meaning does accidental exploitation even have?

Using engines with infinite TWR might be a perfect example of that.

You don't know which engines are massless and which are not, so by accident you might get an enormous bonus in performance to your small satellite, one that never should be there if the engines used wouldn't be massless.

I think this looks like a super-easy fix on the surface, but then I realized you could attach physics-less parts to other physics-less parts... You'd need someway to assign the part's mass to the nearest parent that has physics simulated. This isn't impossible, or even particularly difficult, but it is more complex. That complexity could actually slow down the game

Cache data that requires more complex calculations.

But having parts attached to other parts and passing properties along is stupidly-easy, even for Unity.

Edited July 29, 2014 by Sky_walker