Parts & Vessels Wing Controls Often Being Inverted by Default

[LightStrikeBoom]

I am not sure what causes it but often when building planes the wing control surfaces will work backwards at least visually, though sometimes making the plane unable to fly correctly without inverting them.
I think it is more likely when adding multiple sets of wings though it sometimes happens with only one set.
I am not sure if this guess is correct, but I think it sometimes is the wings getting confused about their position on the craft and whether to change direction by creating drag or pushing the air another direction.

I was having issues putting in a screenshot but when trying to make my craft fly up on non-inverted wings, the main wings angle the control surfaces downwards creating drag in the wrong direction with the wings not being in a position to push the air another direction.
On atleast 1 plane the effect was so strong I had to invert the wings or else the SAS wouldn't work and I would have to press the opposite button I intended.

[Forrey]

I've encountered the same effect, and spent some time trying to diagnose why. I tried making a long plane with pairs of wings at the front and back.

Initially the ailerons would always be inverted while trying to climb/descend, but worked correctly for roll. Inverting the control direction of the wings would thus not work well, as rolling would be reversed.

After many attempts at trying different sizes of wings, eventually the game got to a state where the problem was no longer occurring. I've not managed to figure out the trigger that causes the inverted behaviour. I've tried:

• Adding the wings on either side (on the left, with symmetry adding the right one, or on the right, symmetry adding the left one).
• Adding the wing on one side, then moving it to the other side.
• All 3 different wing sizes.
• With manual edits and without.
• Rotating the wing a little, or adding it at an angled location (ie not sticking out directly left/right.

None of these made a difference to whether the bug occurred or not.

When a plan has a pair of wings at the front and one at the back, (on either side of the centre of mass, I presume), their ailerons will move in opposite directions to each other when trying to climb or descend. I'm not sure this is right, but I'm also not a fluid dynamics expert.  When the bug hit, trying to climb would make the rear aileron turn downwards, and the front one turn upwards.

[HebaruSan]

It would be good to specify which keys you're pressing and what response you're expecting. The notes suggest there may have been a relevant change in the latest patch:

20 hours ago, Intercept Games said:

• Fixed outboard elements of compound wings exhibiting reversed control surface reaction to pitch inputs 

Traditionally, pitch inputs are "reversed" in flight sims because you pull up/back on the joystick to tilt the craft up and push forwards/down to tilt it down. Later this schema was applied to mice and spread to other kinds of games like FPS. (This is why many games have a "reverse mouse Y" checkbox in the settings, some of us got used to that and find the "normal" orientation unusable.) And IIRC KSP1 applied it to keyboard inputs. It may simply be that you have a different expectation of what is normal and what is "reversed" from the devs.

[BigMax]

I had the same problem on almost all my planes in KSP 2. The weird thing is that the problem doesn't occur from the beginning of the plane build but after some changes on the procedural wings.
I use the default keys and when I try to test the plane's controls by pressing "S" I expect it to tilt up (nose up), but the control surfaces goes down and the nose does the same.
Same thing but opposite when I press "W", the plane pitches up (nose up) instead of down.
I have also noticed that if I use the same control surfaces to roll this is reversed and the SAS is completely unusable and causes the plane to go into a nosedive.
Is this the expected behaviour or is it a bug?

[Wacky Jacky]

On 4/12/2023 at 5:41 AM, BigMax said:

I had the same problem on almost all my planes in KSP 2. The weird thing is that the problem doesn't occur from the beginning of the plane build but after some changes on the procedural wings.
I use the default keys and when I try to test the plane's controls by pressing "S" I expect it to tilt up (nose up), but the control surfaces goes down and the nose does the same.
Same thing but opposite when I press "W", the plane pitches up (nose up) instead of down.
I have also noticed that if I use the same control surfaces to roll this is reversed and the SAS is completely unusable and causes the plane to go into a nosedive.
Is this the expected behaviour or is it a bug?

I thought I was going insane.  Spent at least an hour trying to troubleshoot a plane I was working on.  I'm now convinced it's some weird bug.

[QuiescentRabbitt]

Edit: Submitted my own bug report which should be merged which explains the issue in-depth. I'd delete this reply but I can't.

Edited October 28, 2023 by QuiescentRabbitt
I submitted my own report which contains much more information about the issue than this reply did.

[QuiescentRabbitt]

Reported Version: v0.1.5 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 10 | CPU: Ryzen 7 3700x | GPU: RTX 3080 Ti | RAM: DDR4 16GB 3200Mhz

 

Severity: Medium or Low. The issue cannot be completely mitigated, only partially.

Frequency: High. It occurs seemingly every time.

Description: When creating a plane, the game attempts to detect whether or not to invert the pitch of any placed wings based on their placement relative to the COM (Center of Mass). This results in problematic behavior where you have a plane that is designed with it's main wings placed behind the COM in order to achieve the correct lift profile, but the game decides to invert it's pitch control on it's own. You can invert the entire wing, but that will result in an inverted roll profile. This system of automatically inverting the pitch needs to be adjusted, or the player needs to be given the ability to invert pitch in the advanced controls part menu themselves. It can be very frustrating to build a plane that requires wings behind the COM to fly correctly, but doing so results in wings with inverted controls.

I've attached a craft file that contains two identical planes, one where the wings are in front of the COM and it has the standard pitch behavior, and the other where the wings are behind the COM, and it experiences inverted pitch behavior.

EDIT: I looked into how KSP 1 handles this exact situation, and just like KSP 2, it inverts the pitch of any wings behind the COM. However, most people who built planes in KSP 1 made use of the mod FAR (Ferram Aerospace Research), which allowed you to invert Pitch, Yaw, and Roll. So technically, this is problematic behavior in KSP 1 too, but it was addressed by a mod that many people used.

 

Included Attachments:

PitchControlPlanes.json

Edited October 28, 2023 by QuiescentRabbitt