KSP2 EA: Physics simulation quality tests

[Anth]

• Look for evidence of part drift. One of the KSP2 screenshots of a craft in Duna orbit shows obvious part drift. I have quite a few tests I will be doing to test for it.
• Will clipped parts occlude drag/aerodynamics?
• Will a large craft entering into the Eve's (and other planets) atmosphere act exactly the same in KSP2 as it did in KSP1?
• Will node attached tanks (node to node connected)  that are gizmoed out still have occluded drag when exposed to the atmosphere or will this be fixed in KSP2?

• Wheel testing on docking undocking.

[Bej Kerman]

36 minutes ago, Anth12 said:

• Look for evidence of part drift. One of the KSP2 screenshots of a craft in Duna orbit shows obvious part drift. I have quite a few tests I will be doing to test for it.
•  

Could you circle it? I have no idea what anyone is on about. The vessel looks fine to me.

36 minutes ago, Anth12 said:

• Will clipped parts occlude drag/aerodynamics?
• Will a large craft entering into the Eve's (and other planets) atmosphere act exactly the same in KSP2 as it did in KSP1?
• Will node attached tanks (node to node connected)  that are gizmoed out still have occluded drag when exposed to the atmosphere or will this be fixed in KSP2?

Could all be listed under "Will the aerodynamics be passable?" which should be a yes as long as KSP 2 accounts for the shape of the whole vessel and not just how the parts are stacked. Probably necessitated by not using part trees.

[Anth]

3 hours ago, Bej Kerman said:

Could you circle it? I have no idea what anyone is on about. The vessel looks fine to me.

Docking Port Misalignment and Mk2 cockpit to tank (cargo bay?) misalignment

More obvious alignment mk2 tank issue.

Gap between mk2 cockpit and mk2 tank/cargo bay.

What I don't know why it is happening.

The drift appears to be related to the docking ports. If a craft is a tree, then the docking ports are the beginning of a branch and those branches appear to be affected by part drift. The parts before the docking ports don't appear to be affected.

Set Position/Set Orbit in KSP1 can cause severe drift of crafts left behind in a scene. So maybe this is a different manifestation of the same problem.

I will know in 10 days unless they fixed it...

Edited February 15, 2023 by Anth12

[Anth]

19 hours ago, Kerbart said:

If there's still such a thing a physical timewarp: exiting the atmosphere should cut aero forces, and not apply them "as long as physical timewarp is active"

No more physics timewarp as far as I know. It's integrated into time warp. Time Warp under acceleration is a thing in KSP2. Time Zoom was what one of the developers described it.

• Radial Attachment vs Attachment node strength
• Autostruts implementation (if this even exists in KSP2)

[MarcAbaddon]

I'd be surprised if there are not at least degrees of how much physics get calculated in different time warps. It's hard to imagine the full physics simulation (e.g. for the forces on the joints and stuff)  for the rockets running at a very high multiplier. Just allowing thrust under time warp is a lot easier, thought here are some cases to consider, e.g. thrust not properly aligned with the center of mass or thrust that would induce too much oscillation in full physics. If you are mean to the physics engine you could even build a vessel where the center of mass starts moving away from the thrust axis once you have spent 50% of your time.

But just assuming thrust is properly aligned and adjusting speed, orbital parameters and weight under thrust while time warping is relatively easy in comparison.  

[Anth]

• EVA Construction and physics interaction. E.g. in KSP1 when a part is placed it drops slightly due to gravity which definitely shouldn't be happening. Also placing parts will cause the craft to be affected by forces that shouldnt be there.

[The Aziz]

9 minutes ago, Anth12 said:

EVA Construction and physics interaction. E.g. in KSP1 when a part is placed it drops slightly due to gravity which definitely shouldn't be happening

Safety measure against part clipping through terrain or doing other weird things. That 10cm ain't gonna hurt anyone.

[Anth]

• RCS/SAS interaction. (it wasnt great before 1.2 in KSP1 but it could do with some tweaks post 1.2 as well)
• SAS in flight.
• SAS in flight with Time Warp under acceleration. Intercept Games mentioned it in space. They never said anything about it in an atmosphere.
• Close craft to craft testing. In a few versions of KSP1 a plane could fly close to a landed stationary plane on the ground and the landed plane would take off.

Just now, The Aziz said:

Safety measure against part clipping through terrain or doing other weird things. That 10cm ain't gonna hurt anyone.

Safety measure I agree with.

That 10cm (most likely that small drop was dependent on gravity) drop is fixable and for people who want a precise attachment that was extremely annoying. Having to replace it higher than the desired point hoping it would drop to the right point is really annoying. Also I don't think it did that in 1.12.0

• SSTO Planes would maintain its angle on reentry when they shouldn't have in certain situations. This was obvious because it took a slight touch of the controls for the plane to reorientate to its correct angle.

[The Aziz]

Hard to talk about precision in EVA construction if you could only place one part at a time and there was no way to make things perfectly symmetrical. And I've never seen any drops happening on part to part attachments.

[Anth]

The symmetry issue is definitely annoying.

[magnemoe]

20 hours ago, AtomicTech said:

Kraken Drives!

Specifically the docking port based ones.

Also the kerbal on an ladder should not add an force on craft if he bump head or legs into something who is part of craft. This is something who is very easy to create and is annoying for small crafts. 
An kerbal not on ladder will affect craft if bumping into it so going out and pushing will still work.  Its only an exploit because unlimited eva fuel. 
 

[Anth]

3 minutes ago, magnemoe said:

Also the kerbal on an ladder should not add an force on craft if he bump head or legs into something who is part of craft. This is something who is very easy to create and is annoying for small crafts. 

Agreed. that is really annoying.

29 minutes ago, The Aziz said:

Safety measure against part clipping through terrain or doing other weird things. That 10cm ain't gonna hurt anyone.

Just tested it in 1.12.0. There was no drop due to gravity. That happened sometime after 1.12.0. So definitely fixable

[magnemoe]

9 hours ago, Anth12 said:

Docking Port Misalignment and Mk2 cockpit to tank (cargo bay?) misalignment

More obvious alignment mk2 tank issue.

Gap between mk2 cockpit and mk2 tank/cargo bay.

What I don't know why it is happening.

The drift appears to be related to the docking ports. If a craft is a tree, then the docking ports are the beginning of a branch and those branches appear to be affected by part drift. The parts before the docking ports don't appear to be affected.

Set Position/Set Orbit in KSP1 can cause severe drift of crafts left behind in a scene. So maybe this is a different manifestation of the same problem.

I will know in 10 days unless they fixed it...

That could be an user bug with the move tool. The planes has an 6 way connector inside the cargo bay who is the same as the one holding the antennas, docking port would clip trough bay door or door will not close is another weird thing is how the connector is placed into the bay. not connected to front or rear node in bay. I suspect the move tool was used. Why not use the MK 2 radial docking port or secondary the shielded docking port here?  
Also both planes and docking ports has the same error so its part copy or an pretty reliable bug  
Note that its another docking port between the large solar panels. 

[The Aziz]

So all I read here is just a bunch of mentions of known bugs in latest versions of KSP, mostly, or minor annoyances that stayed with the game forever, or something noticed from early footage from the sequel.

But I give you the ultimate hunting challenge

Everything from this channel https://youtube.com/@Danny2462

[snkiz]

I don't think it's a good idea to take away the safety net with persistent rotation. Maybe for a difficulty toggle. A further wrinkle to part clipping, parts placed inside closed structural parts should also be shielded from drag. Without the need to hack-in a cargo module that makes everything not work that touches that part. What's considered inside just needs to better on the whole.

[Bej Kerman]

3 hours ago, Anth12 said:

No more physics timewarp as far as I know. It's integrated into time warp.

And you pulled this from... where?

No more physics warp means no more warp in atmosphere, which IMNSHO, is ridiculous.

36 minutes ago, snkiz said:

I don't think it's a good idea to take away the safety net with persistent rotation.

Just build crafts that are capable of reducing their spin under their own force.

[Kerbart]

8 minutes ago, Bej Kerman said:

And you pulled this from... where?

No more physics warp means no more warp in atmosphere, which IMNSHO, is ridiculous.

The same can be said for this statement. The reason there's physics warp is for those cases where forces are acting on a vessel but you still want to time warp. It's equally conceivable that "no physics warp" simply means that you can use regular warp inside the atmosphere (it's just limited to a certain factor, probably limited to altitude, the same as it is currently). Once the video's start appearing we'll know — and if not we'll know soon anyway — but assuming there would be no warp inside the atmosphere is not evidence based either.

[Bej Kerman]

Just now, Kerbart said:

It's equally conceivable that "no physics warp" simply means that you can use regular warp inside the atmosphere (it's just limited to a certain factor, probably limited to altitude, the same as it is currently)

Why? The entire point of normal warp is to not simulate part forces (especially that are important for atmospheric flight) so you can increase the time acceleration to ridiculous values without breaking the game. You absolutely need to simulate those forces that are thrown out so that atmospheric flight doesn't become exceedingly inaccurate. KSP 2 will have separate physics and rails warp, if you discount the silly idea of them throwing out physics warp for a hacky solution to normal warp that not only limits what you can do with it in atmo, but also degrades the physics simulation for vessels under warp in the atmosphere.

[Kerbart]

7 minutes ago, Bej Kerman said:

KSP 2 will have separate physics and rails warp, if you discount the silly idea of them throwing out physics warp for a hacky solution to normal warp that not only limits what you can do with it in atmo, but also degrades the physics simulation for vessels under warp in the atmosphere.

My point is that you can make that claim with as much certainty as the claim that there won't be physical time warp: until we've seen the game we don't know. They put a lot of work in KSP2, it is unlikely that the internal mechanics are going to be a 1:1 copy of KSP1.

Maybe the game switches smoothly between physical warp and "on-rails warp". We know on-rails is going to be different; I'm not going to make assumptions that physical warp is going to remain the way it is either. Maybe it will still be there. Maybe it will be there but not explicitly recognizable or selectable. Maybe it's replaced by something better. We don't know, that's what I'm saying.

[Bej Kerman]

1 minute ago, Kerbart said:

My point is that you can make that claim with as much certainty as the claim that there won't be physical time warp: until we've seen the game we don't know. They put a lot of work in KSP2, it is unlikely that the internal mechanics are going to be a 1:1 copy of KSP1.

No, but keeping phys warp and rails warp as separate functions only makes sense.

3 minutes ago, Kerbart said:

Maybe the game switches smoothly between physical warp and "on-rails warp".

Elaborate? Without anything to go off of besides this sentence, "switches smoothly" can mean anything.

4 minutes ago, Kerbart said:

We know on-rails is going to be different; I'm not going to make assumptions that physical warp is going to remain the way it is either. Maybe it will still be there.

It's necessary for proper simulation of vessels in atmosphere, so assuming it's 99.99999999999999999999% likely that phys warp will be here just as in KSP 1 is completely justified.

6 minutes ago, Kerbart said:

Maybe it will be there but not explicitly recognizable or selectable. Maybe it's replaced by something better. We don't know, that's what I'm saying.

"something better"? Without any kind of elaboration or actual suggestions for what Intercept could possibly do to top Phys-warp's very simple function of "just speed up the physics rate", just saying "well maybe there's something better" doesn't mean much and only serves to discredit the fact that physics warp only has one function that it already carries out very well.

[Kerbart]

Just now, Bej Kerman said:

No, but keeping phys warp and rails warp as separate functions only makes sense.

Elaborate? Without anything to go off of besides this sentence, "switches smoothly" can mean anything.

Well, I don't have a crystal ball, so I can't elaborate. So yeah, it can mean anything. Isn't that exciting?

Just now, Bej Kerman said:

It's necessary for proper simulation of vessels in atmosphere, so assuming it's 99.99999999999999999999% likely that phys warp will be here just as in KSP 1 is completely justified.

By quoting a gazillion digits you're making it hard to take that statement serious. I'd say "99%" is pretty confident, or even 90%. As we're on the topic, can you elaborate why you're 99.99999999999999999999% instead of 99.9999999999999999999%? I'm curious.

Just now, Bej Kerman said:

"something better"? Without any kind of elaboration or actual suggestions for what Intercept could possibly do to top Phys-warp's very simple function of "just speed up the physics rate", just saying "well maybe there's something better" doesn't mean much and only serves to discredit the fact that physics warp only has one function that it already carries out very well.

The simplicity of "just speed things up" is exactly the problem. There's this thing called "Newton's laws of physics," maybe you heard of it. Speeding things up 10× means your accelerations go up 10×. That means your forces go up 10×. Don't tell me your parachutes have never been ripped off while under "4×" (or whatever the triangles mean) physics warp. Not having to worry about that is what I mean by a better Physics warp. SAS working the same way and handling slight COM offsets the same way as when not warping, etc. There's a lot that can be improved, and maybe hacking the timescale is not the way to go. I don't know, but there's clearly room for improvement and I have faith in the devs that they looked into it.

[Bej Kerman]

4 minutes ago, Kerbart said:

Don't tell me your parachutes have never been ripped off while under "4×" (or whatever the triangles mean) physics warp.

My parachutes have never been ripped off while under 4x acceleration.

Sure, larger vessels flex more like they become heavier. But no, this isn't a problem with the function of phys warp itself or how it's been integrated into gameplay. This is just a minor backend issue that BetterTimeWarp fixes with its accuracy toggles. Phys warp does not need to be functionally different.

[The Aziz]

They used to rip. Like, before 1.0. Before stability fixes arrived.

[Kerbart]

1 hour ago, Bej Kerman said:

My parachutes have never been ripped off while under 4x acceleration.

It still causes issues deploying them under warp. I use the SafeChute mod to prevent that from happening. Maybe not ripping, but there's still can be issues under physical warp.

[snkiz]

7 hours ago, Bej Kerman said:

Just build crafts that are capable of reducing their spin under their own force.

It can take an incredible amount of skill to figure out how to stop a spinning craft.  The us space program almost didn't happen due to not being able to wrap their head around orbital maneuvers, Despite having the math backing them up. It's enough that a novice might just give up. Saying just add Moarr Reaction wheel is like saying Moarr boosters, but less obvious. Sure you can brute force it. Hell if the reaction wheels are as still as op it won't be much of an issue. But it can be, how much reaction force you need is also a learned skill.