Don't completely discard mass of physics-insignificant parts

[RidingTheFlow]

There are all these "mass-less" or "physics-insignificant" parts which allow intentional or unintentional balance-breaking behaviour.

I understand that its very beneficial to exclude lot of tiny parts from physics calculation for performance benefits.

However, do we really need them to have "zero real mass"? As I understand, all of these parts actually have mass in their part files - they could, for example, just add this mass to mass of "parent" part (assuming its physics-significant part).

This will ensure that if I add 100 (say) batteries with mass of 0.02, my craft mass will go up 2 tons, while not actually having drawback of adding 100 parts to physics calculation.

Edited June 20, 2014 by RidingTheFlow

[Superfluous J]

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.

[NWM]

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?

[Kasuha]

The main reason (IMO) for introducing more and more massless parts is performance. The engine spends way less time calculating physics simulation if there are less parts on which the simulation is calculated.

I agree that mass of these parts should not be lost but I think it should not be simply added to the nearest massy parent part. Instead, I think, it should be distributed over all "massy" parts of the ship proportionally to their dry mass. That would allow to keep the ship balanced even in case these parts are placed asymmetrically. And with this, I'm meaning planes rather than rockets.

[RidingTheFlow]

It could actually adjust both mass and center of mass (just once, on launch for exampe), this way statical balance will remain the same as if these parts were physics significant.

But balance should be affected by physics-insignificant part, e.g. if you place many massless RCS nozzles or solar panels on one end of the plane it should cause proper balance shift.

Edited June 18, 2014 by RidingTheFlow

[Superfluous J]

I agree that mass of these parts should not be lost but I think it should not be simply added to the nearest massy parent part. Instead, I think, it should be distributed over all "massy" parts of the ship proportionally to their dry mass. That would allow to keep the ship balanced even in case these parts are placed asymmetrically. And with this, I'm meaning planes rather than rockets.

I don't see the benefit to giving the player this free symmetry. We have to balance everything else, why not these "massish" parts?

[Vaporo]

The main reason (IMO) for introducing more and more massless parts is performance. The engine spends way less time calculating physics simulation if there are less parts on which the simulation is calculated.

I agree that mass of these parts should not be lost but I think it should not be simply added to the nearest massy parent part. Instead, I think, it should be distributed over all "massy" parts of the ship proportionally to their dry mass. That would allow to keep the ship balanced even in case these parts are placed asymmetrically. And with this, I'm meaning planes rather than rockets.

But what happens when someone detaches a part? Does detached the part keep the mass added by the adjunct pieces on all of the undetached parts, or does it instantly decrease in mass?

Also, people could make ridiculously unbalanced probes with this model. If you're designing a really tiny probe, you could add a huge number of relatively light but still very significant adjunct parts on only one side without affecting stability, when your center of mass should shift a huge way to one side.

Edited June 19, 2014 by Vaporo

[BudgetHedgehog]

I'm fine with massless parts as a general rule. I don't want to have to add two thermometers to simply balance my lander or whatever because I like to crowd the tiny sensors around my crew hatch because it's super easy to EVA and grab the data then - adding a duplicate of everything on the other side just to make the craft not tip over while thrusting increases part count which is a bad thing. So yes, I'm entirely in favour of massless parts.

However, what I do have a problem with is how they're simply and totally ignored in flight. I would much prefer it if their mass were added to the ship as a whole (if any mod authors are reading this, there's an idea for a plugin right there) - that way, the craft would still be balanced no matter how many small radial batteries I put on one side but I would still have to have enough fuel and thrust to carry them around. It's the best of both worlds, I think - people don't have to worry about bringing duplicates of most small things but they still need to have to account for carrying one.

Also, SQUAD, please dear god make the new large decoupler non-physicsless in 0.24. Most, if not all, players who use it have encountered the bug with it so are changing it anyway.

[Kasuha]

But what happens when someone detaches a part? Does detached the part keep the mass added by the adjunct pieces on all of the undetached parts, or does it instantly decrease in mass?

Each docking/undocking/decoupling/crash already comes with discarding old ship(s) and creating new ship(s). So it can also come with recalculating the mass distribution. And even now massless parts gain their lost mass if they get detached from anything massive, without that we'd have cubic octagonal struts flying at speed of light everywhere.

Also, people could make ridiculously unbalanced probes with this model. If you're designing a really tiny probe, you could add a huge number of relatively light but still very significant adjunct parts on only one side without affecting stability, when your center of mass should shift a huge way to one side.

I don't think it is a bad thing. You don't always need two of everything and you can't always mount everything on central column.

[Sky_walker]

I don't think it is a bad thing. You don't always need two of everything and you can't always mount everything on central column.

It's bad because it wipes out any illusion of realism we have, not because people might want to use it as something good for their designs.

Edited June 19, 2014 by Sky_walker

[Kasuha]

It's bad because it wipes out any illusion of realism we have, not because people might want to use it as something good for their designs.

What I consider bad is trying to impose personal notion of correct gameplay on others.

If you like your rockets looking 'realistic' (in any personal meaning of the word 'realistic'), nobody prevents you doing so and nothing is going to prevent doing so even with that change.

[LethalDose]

I'm okay with keeping, for lack of a better term, "trivial" parts physics-less, as is. Yes, it screws up realism, but I think it's a trade-off that is worth it for the improvements it brings to gameplay.

That being said, i don't think physic-less properties should be exploited. I think limiting the number of parts on a vessel that are physics-less at launch would be a solution. Maybe, no more than half the parts at launch can be physics-insignificant.

But really, IMO it seems a moot point. If you think spamming physics-less parts is exploity, don't use that exploit.

[Duxwing]

What I consider bad is trying to impose personal notion of correct gameplay on others.

We necessarily impose our personal notions of correct gameplay onto others however we influence SQUAD's decisions because whatever they decide, someone will dislike their decision.

If you like your rockets looking 'realistic' (in any personal meaning of the word 'realistic'), nobody prevents you doing so and nothing is going to prevent doing so even with that change.

By your logic, we therefore should allow players to change the mass of ships in flight: if players like their rockets looking "realistic (in any personal meaning of the word 'realistic')" then they can just ignore this option whilst everyone else flies at arbitrary fractions of lightspeed.

-Duxwing

[Kasuha]

By your logic, ...

You're trying to beat up a strawman.

In current game, the ship below is an example of perfectly fine and balanced rocket. Of course, most people don't build such ships because they consider them ridiculous. On the other hand, you can have a lot of fun with them if you can get over your obsession with realism and accept the fact that KSP is a game.

-Duxwing

I wonder what makes people put signatures into their posts if they are obviously aware their nick is already to the left of each their post by default and there's even special part of configurable area below each post which can be set up to hold any kind of constant signature anybody would like to have.

[Justin Kerbice]

[...] you can have a lot of fun with them if you can get over your obsession with realism and accept the fact that KSP is a game.

I wonder what makes people put signatures into their posts if they are obviously aware their nick is already to the left of each their post by default and there's even special part of configurable area below each post which can be set up to hold any kind of constant signature anybody would like to have.

you're more than right on this, people willing to get realism are quite "foolish" IMHO as long as all single physical/chemical/mechanical/nuclear/... laws can't be there all together in a single simulator. And there are enough simulators of real world (FS for planes/choppers for example) to let kerbals be just kerbal and live in their own universe.

The sig question is funny Perhaps they doubt we don't recognize them .

[RidingTheFlow]

Parts like thermometers are very light, and should not shift centre of mass by any significant degree, so unlikely you will need to balance a single thermometer.

If you, however, place lot of your science parts to one side so it overcomes your control authority, you better think of distributing them more evenly, I see nothing bad with that.

There is no need to be obsessed with realism as long as it does not result in balance-breaking behaviours (e.g. ion engine along with needed plumbing has certain low TWR for balance reasons, but by using the massless parts you can circumvent it, even without knowing).

I don't need it to adhere to exact physical mass/momentum calculations, I just wan't to get rid of magical batteries which made of air

Edited June 19, 2014 by RidingTheFlow

[karolus10]

I guess that Physic-less parts should add additional mass to it's parent part, it's actually very useful, because You can balance Your ship much easier as every attached batteries, ladders, etc. aren't influence ship center of mass.

EDIT_1: also please notice that OP suggest adding phyisics-less parts mass to total ship mass without making them physics enabled.

Edited June 20, 2014 by karolus10

[NWM]

As I concern, adding the mass to the parent's mass is not enough, those massless parts would also affect the centre of mass too. Any other case doesn't makes those impossible "house-and-woods" rockets unstable. So the attached part should affect the position of the centre of mass of the parent part too.

[sal_vager]

There is a reason those small parts were made physics-less, parts below a certain size are difficult for Unity to cope with.

This is also why the pods were made larger, so Kerbals themselves could be big enough to avoid the Unity weirdness.

[RidingTheFlow]

It does not really matter what the reason they were made physic-less, because this thread is not about adding them back to physics. Its about discussing how to stop their mass being unaccounted, which affects delta-V and TWR (without actually adding them to physics).

Edited June 19, 2014 by RidingTheFlow

[Vindelle_Sunveam]

AS much as I can try to think of it being a problem, the end of massless parts isn't one at all.

People doing assymetrical probes will still have enough control authority to pilot their robots, and in case they do not anymore, they just have a new challenge (dumb duplication isn't the only way to go and I'm sure you are aware of it, do some geometry). Challenge : i.e. renewed source of fun.

And finally, the quite obvious : people who really want it, but do dot now, will be satisfied.

Tell me if I'm wrong, but it seems to me that it is quite a good thing : people get what they want without preventing the others from enjoying their playstyles.

EDIT : and also, no 2 Tons electric gear unnacounted for.

Edited June 19, 2014 by Vindelle_Sunveam
because of reasons.

[RidingTheFlow]

Even if not 2 tons, with small probes I found that some battery types made for very "awesome" deltaV/TWR capacity with ion engine, just because I've picked parts with zero apparent mass.

I was actually quite puzzled with this first, because I wasn't aware of this behavior (since its not actually documented anywhere ingame, and game still shows sensible mass for every part in UI) - and didn't quite understand why some of my tiny ships had crazy amount of deltaV while some others of (supposedly) same mass didn't.

Edited June 19, 2014 by RidingTheFlow

[Jouni]

Massless sensors and ladders are fine, and even massless lights are borderline ok. Massless solar panels and batteries make about as much sense as massless engines and fuel tanks would. Massless RCS thrusters are ridiculous, because they used to be heavy. A set of four thruster blocks used to weight 200 kg, which was a significant fraction of the payload in many small landers. Before 0.23.5, I often left RCS thrusters out from Apollo-style landers, using them only in the CSM, because it increased the delta-v significantly without making docking any harder.

[cpast]

RCS thrusters are massless? Those literally *are* a kind of engine.

[AlamoVampire]

i for one think that some parts SHOULD be "massless." Why? Well, look at it like this, some parts are absolutely tiny, does it make sense to make them add any appreciable weight to the vessel? not really. I could see it becoming an issue if say you made STRUTS weight something, seeing as we still need to strut stuff and in some peoples case <looking at mr whackjob and myself> we tend to go on the heavy side with them, but by and large, a blanket no more massless parts is a bad idea to me as it COULD force needless part duplication just to maintain vehicle stability during flight or ground ops. YES, HUSH, I KNOW its been said before, but, it should be repeated. lol