Please no wobble (Solved!!!)

[Strawberry]

Just now, Bej Kerman said:

That's not a reason, the VAB isn't tiny and and these limitations aren't realistic.

If you got an unupgraded VAB (which I assume theyll introduce if we get height/mass limits) then yeah the VAB is tiny and a small VAB will have more limits then a massive one.

[Superluminaut]

1 hour ago, Bej Kerman said:

Honestly, dynamic limitations introduced by your designs and their physics sounds a million times better than arbitrary limitations imposed by fixed values that have no reason to exist besides Da Balance

Engineering is all about fixed limitations.

If you use a fuel tank, that tank will buckle under x load.

Dynamic spring joints don't model even a fraction of possible fail states. They are also a very unrealistic model. If you wanted to use springs, forgo the joints and make the entire fuel tank a spring

Spring joints are simply a robust game development technique used to connect objects in physics simulations. They are not a physically sound model of an assembly in their KSP application to any extent.

Edited March 3, 2023 by Superluminaut

[Zacspace]

I was honestly hoping that in the sequel they'd move away from modeling every part as its own physicsbody with joints and instead do something like simple rockets 2 where everything is welded together, but with some sort of simple structural analysis so our vehicles can still react and break under stress.

That said, I don't think the joints being as springy as they are presently is a deliberate design choice. Just something that hasn't been dialed in yet. Like SAS, or wheels, or aerodynamics or... almost everything. Eventually They'll get around to tightening things up like in KSP 1.

[tstein]

On 3/2/2023 at 12:46 PM, BowlerHatGuy3 said:

Jiggly rockets are absolutely intentional as the jigglyness would be a very easy fix, as in literally changing a few numbers.

I do think that they should stay for the most part to make sure that you don’t make your rocket too tall and so that your craft can be pulled apart by wind forces. But as they are in the game right now rockets are way too flaccid. 

Just adding autostrut is kind of a lazy fix imo. I’d much rather have them change the actual values.

 

In fact no. make joints too rigid with the very skewed masses ratios in  the ships and you can  wake the kraken  really violently unless you make a system with dynamic neutralization of joints. That said I agree that it seems intentional, as if the producers of KSP2 liked the stupid part of KSP1 more than the usual players did.

[Mechanic]

You would think that with all the great ideas KSP1 modders had that some of them would have been noticed by the devs. Rockets can flex but not noticeably. Anything over a few degrees would fracture. For the game, parts should be solid or break completely. Remember Butter's complaint from South Park after seeing Game of Thrones?

[Superluminaut]

On 3/2/2023 at 3:18 AM, RayneCloud said:

We've seen some stronger and more advanced strut parts in the back end, so this might be some sort of design decision to force players to build smaller and more compact vehicles at the start of their campaign, using a Tech 1 strut to move to larger vehicles and a Tech 2 strut to go even larger. I think the problem is that, the joint rigidity is way to low even if this was a design decision. Though, if you fly the stock rockets the K1 and K2, they have no issues with wobble what so ever. (The K2 needed fixing, so I threw a stack separator in it.)

This is discouraging. I hope that tech 2 struts have a different appearance, rather than being a beefed up tech 1.  If you want to force players to build small, would it not make sense to have parts simply break off. Why keep them bolted on with rubber bands. Larger parts would simply have beefed up breaking strengths, progression solved. The whole rubber band effect screams bug. If a part is already hanging overboard, why bother holding on to it unless it wasn't meant to go yet.

 

However, your post did get me thinking.

Maybe the true attachment mechanic is still unplayable, and they rigged up this terrible mess to prop up the game in early alpha. Putting, "real joints" on the road map would be awkward. So maybe it's a placeholder.

Is there any evidence in the code to suggest a second attachment mechanic? Or currently unused functions tied into joints?

[TackleMcClean]

Autostrutting is a band-aid to a symptom of a problem further up the line.

Please don't keep the rockets so noodly-wobbly. It's novel and "fun" about 1 or 2 launches, after that it's just frustrating and the gameplay of designing rockets is not made more fun by this approach.

[triste_lune]

On 3/2/2023 at 5:31 AM, Superluminaut said:

I'm kind of stunned that an artifact of the original game's game engine limitations were carried over to the sequel.

Wobbly rockets were always a bug. The KSP1 devs spent years trying to minimize the problem, even bringing on new members to work on the issue.

Most people don't like them, and they introduce an un-intuitive stumbling block for new players or people that want to learn space. eg. Rocket veers off course on launch. Why? The control part wobbles away from the heading, resulting in SAS shenanigans and off COM thrust.

Furthermore, everyone gets rid of wobble to the best of their ability by adding struts, resulting in a higher part count. So you have a feature, that only produces greater part counts. Why?

To keep the destructive effect, just define stress tolerances for parts at which they explode, disconnect, crumble or shear.

Also, real rockets don't wobble.

Scott talking to KSP1 devs about the wobbly rocket bug.  They go off on tangents but almost the entire rest of the interview is on the topic.

If you're new to KSP, wobble is that wet noodle, jello rocket thing.

 

Please get rid of wobble all together. Thank you.

It always has been a feature, maybe at first it as  been a bug, but it has become a feature. And it has never been an unsolved issue.

If you didn't like it, you just have to install a mod kjr Kerbal join reinforcement and it's solved

There is already a mod for ksp2 to allow you to tweak the wobble value or you can edit the XML file and tweak the value manually. There is a post on this forum explaining how to do it on ksp2.

So no it's not a bug and it can be tweaked, removing it definitely NO but adding an option in the campaign setting allowing players to disable the wobble for this campaign YES this way everyone can choose how they want to play

[Superluminaut]

An example collapse of a pressure supported rocket. No noodling, folds over, then rips open.

 

[kicka55]

While I agree that excessive wobble is unrealistic and should be avoided, some amount of wobble is a game feature. It provides a sense of power as your engines roar alive. They actually push the rocket up. It's not just an animation while the rocket moves up magically. So a small level of wobble and shake is needed to convince a player that what is happening on screen are real physics at work and not just a cheat. 

I hope I could make you more comfortable with the idea behind wobble. At least from my perspective. Cheers!

Edited March 8, 2023 by kicka55

[Why485]

Wobble should be able to happen, but only for extreme cases. A reasonable looking rocket just shouldn't wobble. I play with Kerbal Reinforcement Next and the way this mod handles it is how the base game should be. Struts should only be used in extreme situations where a part is connected in an awkward way such that it a sufficient torque would be problematic. To give some examples of what, in my opinion, is the KSP joint system working the way it should be:

A ship like this should never wobble.

A ship like this might wobble a tiny amount, and really just the boosters since they are generating so much thrust off-axis and are connected through only a single ejector. You can probably get away without strutting something like this down, but you might want to for the extra stability.

A "ship" like this should wobble, because it's a very powerful rocket connected in a very unstable way. This wobbles so badly I needed to send an EVA mission up to strut it down, after which point it still wasn't the most rigid thing ever, but it was usable.

 

Edited March 8, 2023 by Why485

[Bej Kerman]

2 minutes ago, Why485 said:

Wobble should be able to happen, but only for extreme cases. A reasonable looking rocket just shouldn't wobble. I play with Kerbal Reinforcement Next and the way this mod handles it is how the base game should be. Struts should only be used in extreme situations where a part is connected in an awkward way such that it a sufficient torque would be problematic. To give some examples of what, in my opinion, is the KSP joint system working the way it should be:

A ship like this should never wobble.

A ship like this might wobble a tiny amount, and really just the boosters since they are generating so much thrust off-axis and are connected through only a single ejector. You can probably get away without strutting something like this down, but you might want to for the extra stability.

A "ship" like this should wobble, because it's a very powerful rocket connected in a very unstable way. This wobbles so badly I needed to send an EVA mission up to strut it down, after which point it still wasn't the most rigid thing ever, but it was usable.

 

Wobble that puts any gaps between a parts' connections should cause them to break as well.

[Superluminaut]

23 hours ago, kicka55 said:

While I agree that excessive wobble is unrealistic and should be avoided, some amount of wobble is a game feature. It provides a sense of power as your engines roar alive. They actually push the rocket up. It's not just an animation while the rocket moves up magically. So a small level of wobble and shake is needed to convince a player that what is happening on screen are real physics at work and not just a cheat. 

I hope I could make you more comfortable with the idea behind wobble. At least from my perspective. Cheers!

As artistic license, wobble seems very cartoonish, like Wile E. Coyote taking  a running start. It's not real physics.

I actually think kerbals are that gauge of intensity you're looking for. Kerbals shake, vibrate, and have panic attacks. As a player you mirror their emotions and get a feel for the crazy excrements your vehicle is going through. Also kerbals are happy-go-lucky and have different personalities, so you want to save them, you're emotionally invested in the success of your missions. In orbiter if you get stuck on the moon you just try again. In KSP you launch the rescue mission, 10x more powerful than the original mun lander mission. There have been a lot of rocket sims, but KSP is the one that really connects with people, and I think the differences is the kerbals. Both KSP1 and KSP2 could do a much better job making use of the power of kerbals, in my opinion.

KSP1 also added camera shake.

---

Basically, if you can see the rocket flex, it's already over and you should be mashing that abort button to save your kerbals. As a "kerbal failure mode" I would be fine with it. However flex must be the start of a total failure, a rocket that noodles itself to space is just too ridiculous. I would also like to see the introduction of more realistic failure modes.

As far as I know the closest thing to wobble that rockets ever produced was called pogo, and has been solved.  https://www.nasa.gov/feature/50-years-ago-solving-the-pogo-effect

However pogo oscillations are in the direction of the length of the rocket, not laterally. They also didn't compress and rebound the structure, they lurched the entire vehicle forward, to a larger magnitude than what one might experience as vibration.

Almost all vibrations in a rocket come from combustion in the engines. They are not the result of flex in the structure. Rocket's don't sway like tall buildings.

Some rockets do vibrate more than others. Multiple engines typically cancel out a lot of vibration. SRBs are a pretty rough ride. Hot staging is smoother than regular staging.

 

Edited March 9, 2023 by Superluminaut

[kicka55]

How can you say it's not real physics when KSP models physics. It's just that the tanks are not welded together like in real life. They are stacked together with some kind of wobbly glue. That's the Kerbal way. Just leave it at that. The target audience are not grown ups who complain about such things. I'm sure there will be mods to turn it into a grown up boring simulator down the line.  Meanwhile just stick to KSP1.

Edited March 10, 2023 by kicka55

[TheOtherDave]

On 3/9/2023 at 1:27 PM, Superluminaut said:

As artistic license, wobble seems very cartoonish, like Wile E. Coyote taking  a running start. It's not real physics.

If it was just some cartoonish effect, I probably wouldn’t care. It makes things soooo hard to control, though. For me the game is easier to play at like 5 fps without the wobble than at 30+ fps with the wobble.

[Superluminaut]

Nate Simpson - creative director

from the 3/24/23 AMA

On wobbly rockets

Quote

This is a really good example of how having something in early access helps us prioritize and focus on the right things. This is obviously a very hot topic within the community, and it's also something that is frequently discussed within the team. I will describe my general goal for this.

When something is very skinny and made of many stacked parts, it should wobble. I think that if we were to move completely beyond rigid body physics, that we would have kind of subverted one of the things that's very fun and funny about this game. Do we want larger vehicles, do we want our interstellar vehicles to be wobbling around, do we want stuff that's larger than, lets say the 3.75 core size, to be wobbling all over the place? We do not. We are not happy with the current wobbliness of the vehicles. This is an area of current focus and heavy iteration and testing. And it will get better.

 

[Superluminaut]

4 minutes ago, Superluminaut said:

Nate Simpson - creative director

from the 3/24/23 AMA

On wobbly rockets

 

I think creative director Simpson is imagining something like the flight of a dart.

 

There are multiple problems with this.

Rockets are built to be ridged, specifically to avoid flex.

Rockets are not homogeneous, they have weak points that give before other points.

It would be fun as a fail state, and a nuisance at any other time.

Most players will encounter the problem, realize struts aren't decorative, and from then on wobble becomes the revert, "need more struts" grind.

[Strawberry]

I agree with the opinion that long rockets should wobble, very much disagree with the claim that multi stacked parts should wobble. For many parts the only options you have are short parts, for example the oscar fuel tank. You shouldnt have to deal with wobble just because the game doesnt have the right part. Not to mention there are definitely asthetic reasons why youd want to use lots of stacked small parts. I like constructing rockets with lots of truss adapters, and I dont think I should deal with lots more wobble because I wasnt lazy and used a large fuel tank instead. While you could introduce new parts for this, this feels bloaty especially on top of an already long tank list. Personally I think itd be good if joint strength adjusted to length of a part. 

[Royalswissarmyknife]

Building an Iss recreation the station is almost unplayable due to the wobble with only 3 modules.

[PDCWolf]

On 3/2/2023 at 7:37 AM, MarcAbaddon said:

I think you need the physics underlying the wobble for certain aspects of the game and there are rocket builds that should wobble. But it needs to be tuned down, or controllable via autostruts or something similar.

No you don't. The Wobble comes from Unity's default joint system and their misapplication of it, and their inability to put in the proper work in the 3 delayed years for a proper foundation for the physics. Autostrut was a KSP1 bandaid to try and control the issue, not a fix.

On 3/2/2023 at 8:18 AM, RayneCloud said:

We've seen some stronger and more advanced strut parts in the back end, so this might be some sort of design decision to force players to build smaller and more compact vehicles at the start of their campaign, using a Tech 1 strut to move to larger vehicles and a Tech 2 strut to go even larger. I think the problem is that, the joint rigidity is way to low even if this was a design decision. Though, if you fly the stock rockets the K1 and K2, they have no issues with wobble what so ever. (The K2 needed fixing, so I threw a stack separator in it.)

It's not a "decision", struts and then autostruts were a workaround, and by now they're both still a workaround and proof of their failure to put in proper work in the physics department. Them saying "they want wobble" is borderline a cope. They can't remove the wobble without changing the joint system, and you can easily go to that config file and set rigidity to something ridiculous, and wobble will still be there (in fact, it was one of the first things everyone tried once they found out about the file).

KSP Wobble is not analogous to anything in real life. IRL rockets are integrated vertical stacks of parts that are both designed for and almost uniquely related to each other, with clearly demarcated structural limits, they'll bend a bit, then more, then fail catastrophically, nothing like the wet spaghetti crap the game has. Even if you wanted to make it pass as some sort of penalty for "tall stacks of small pieces", you can try stacking stuff IRL like books and it still wont bend.

On 3/8/2023 at 8:28 PM, Why485 said:

A ship like this might wobble a tiny amount, and really just the boosters since they are generating so much thrust off-axis and are connected through only a single ejector. You can probably get away without strutting something like this down, but you might want to for the extra stability.

Then it means the radial attachment points are bad. Unrealistic, unintuitive. Why make a part to attach stuff to a side when you also need another part to hold it down?

On 3/8/2023 at 8:28 PM, Why485 said:

A "ship" like this should wobble, because it's a very powerful rocket connected in a very unstable way. This wobbles so badly I needed to send an EVA mission up to strut it down, after which point it still wasn't the most rigid thing ever, but it was usable.

No. It would mean your hydraulic assembly or ball pivot or whatever mechanism (the one inside the claw you use to recenter your craft to point to the center of mass) is not suited for the mass. Unintuitive since it's the correct size node for the part it's attached to.

Edited April 14, 2023 by PDCWolf

[TomKerbal]

Wobbling is often a result of a not optimized physical spring/damper/mass system what is often used to simplify multi body parts in a realtime simulation. Solution would be to find the optimal damping constant (where it is exactly overdamped, or critically damped). It's not so hard to do if you know what you have to do, but a pain in the ... well, if you do not know what to do.

Edited April 16, 2023 by TomKerbal

[thewhitemetroid]

Noodle rockets are dumb, unfun, and unrealistic. IF starship launches tomorrow, at 394ft tall, who's willing to place bets that it doesn't fly up like a stupid wet noodle.

[Little 908]

On 3/1/2023 at 8:31 PM, Superluminaut said:

Also, real rockets don't wobble.

 

Because real rockets are made of metal, not  styrofoam repainted to look metallic lol. I mean real rockets bend a little like literally everything else, e.g. skyscrapers.

 

Also im pretty sure real rockets aren’t covered with space tape wall paper xd

Edited April 17, 2023 by Little 908

[thewhitemetroid]

2 hours ago, Little 908 said:

I mean real rockets bend a little like literally everything else, e.g. skyscrapers.

Skyscrapers are engineered with earthquake and wind shear factors, they are designed to sway. Because they are anchored to the ground , earthquakes and wind shear create moments in the structural steel which need to be overcome buy designing the building to sway X number of feet/meters. Otherwise the buildings would crumble just like the rockets in the videos. A rocket is not anchored to the ground therefore it is not governed by the same design considerations. Also, rockets are pressure vessels and any areas where the metal becomes stressed, e.g. the point of flexure, a real risk of failure can occur just due to the pressure inside, not to mention the fact that a hollow cylindrical shape does not behave in this way. Any aluminum can will demonstrate this point abundantly. No flex, only failure.

[rjbvre]

I understand where people who don't like wobble are coming from,  but there has to be some punishment for rockets that are too tall for their stack diameter and/or use too small couplers. One of the big advantages to the wobbly rockets system is it gives you progressive feedback to how bad your design is. Having rockets flex more while having a higher resistance to snapping allows for a lot of visual cues for your rockets weaknesses.

Is your design not too bad? You'll see a little wobble but your craft should fly well enough to complete the mission. You'll know for next time you were cutting it a little close

Moderately bad? You'll start seeing considerable flex and it becomes tougher to steer your craft. You might be able to complete the mission if your careful, but it might not be worth trying and you'll know better going forward

Really bad? It'll either finally snap at some joint or will be uncontrollable. Back to the drawing board

It sounds like most people on here agree that some changes are needed, and devs have confirmed they're working on them. It's also a big reason why procedural tanks would be great: fewer joints in tall stacks. Still though, I've launched a lot of rockets in KSP2 by now and I don't have many issues with wobble. How bad are people's rocket designs on here? And lets be honest, the reason rockets don't flex significantly in real life isn't because they can't, it's because there are large teams of well educated professionals designing them not to.