Wolfhound & Cheetah engine thrust off-center

[sevenperforce]

On 3/16/2018 at 5:51 PM, Phreakish said:

Can confirm I'm seeing this as well. No mods of any kind. Any time I turn off SAS, it's a whirlygig. 

Tried with multiple pods, tanks, etc to rule out odd interactions with certain parts. The engines are definitely off-axis.

Yeah, blew my first attempt at an Apollo Mun lander completely haywire.

13 hours ago, invision said:

so i just used the wolf hound and alt f12 to space and went behind kerblin to see how far it can go on a mid range tank and PFFT it can leave the solar system, it is off center too if you dont SAS it spins the craft.

 

 

 

Unreal. High thrust and a big engine bell, sure, but that is just ungodly isp, particularly in Kerbin-scale play. The SPS was 319 s. Isp over 400 would be okay for an RL-10 clone, but good grief, not this.

[sevenperforce]

Another thought:

 

[g00bd0g]

To compound things even further.

I manually re-centered the wofhound engine, only to discover the radial attachment points are now off center! So you can have the thrust centered, or the radial attachments centered, but not both...

 

[Mark Kerbin]

Can once again confirm that the wolfhound is STILL off center

[Delbrutis]

On 3/18/2018 at 2:27 PM, g00bd0g said:

To compound things even further.

I manually re-centered the wofhound engine, only to discover the radial attachment points are now off center! So you can have the thrust centered, or the radial attachments centered, but not both...

 

Can I ask what your adjustment was? Don't see much need to radial attach direct to the engine. Not that it should not be working to begin with.

[g00bd0g]

2 hours ago, Delbrutis said:

Can I ask what your adjustment was? Don't see much need to radial attach direct to the engine. Not that it should not be working to begin with.

I used the "non-snap" move tool to adjust the outer edges of the woolfhound engine to be aligned with the tank above. Then, when I attached the RCS using the 4 way symmetry I noticed the symmetry was not aligned with the tank on top, as shown by the obvious ladder-RCS alignment.

[Delbrutis]

Oh ok. I thought you wrote a patch or edited the config file to offset the node. Yeah you can do it in the editor but you have to screw with it every time. Thank's I have been waiting for someone smarter than me to do a MM patch to offset the node properly. Might still screw up the attach points though ? There is already a patch for the MEM's com on SpaceDock .  Thanks

[Mark Kerbin]

Has this been fixed?

Or do I need to fiddle with config files until i realize im not qualified to do anything about it.

[klesh]

27 minutes ago, Mark Kerbin said:

Has this been fixed?

 

There hasn't been a game update post MH lauch, so no it hasn't been fixed. I imagine it will be fixed with the MH patch mentioned in this week's KSP Weekly.

[Mark Kerbin]

1 hour ago, klesh said:

 

There hasn't been a game update post MH lauch, so no it hasn't been fixed. I imagine it will be fixed with the MH patch mentioned in this week's KSP Weekly.

Ok thanks.

I let my steam auto update overnight so I dont always see patches when they happen. =P

 

Wish me luck launching my super aerodynamic fuel station

(I ended up removing the wolfhounds and substituted poodles bc i just cant trust em yet)

[klesh]

1 minute ago, Mark Kerbin said:

(I ended up removing the wolfhounds and substituted poodles bc i just cant trust em yet)

 

For what its worth, I never even noticed the off-center thrust on the Wolfhounds as SAS seems to be enough to keep your ship on course.

[Mark Kerbin]

2 minutes ago, klesh said:

 

For what its worth, I never even noticed the off-center thrust on the Wolfhounds as SAS seems to be enough to keep your ship on course.

I didn't notice either, however this station was already having enough stability problems (SAS and game crash wise) so I figured it would be nice to eliminate that as a variable.  Make no mistake, my computer can run it, its just the physics bomb from Rapid Unplanned Disassembly screwing everything =P 

Edited March 24, 2018 by Mark Kerbin

[fourfa]

Here's another configuration error in MH parts:

 

Edited March 25, 2018 by fourfa

[Snark]

Moving to Making History Discussion.

[fourfa]

Applying 'CoMOffset = 0.00037, 0, 0' to the Wolfhound seems to cause the CoM to align with the center of thrust on the bare engine.  However that that still doesn't change the off-center thrust at all, just helps quantify how much offset there is.  I guessed there might be a command CoTOffset (as there is CoMOffset and CoPOffset) but it had no effect.  I gather from reading other threads on creating engines that the thrust center may be baked in while creating the part in the Unity editor?

Anyone have other ideas on homegrown fixes?

[klesh]

9 minutes ago, fourfa said:

Anyone have other ideas on homegrown fixes?

 

SAS, pretty much.

[RoboRay]

23 hours ago, fourfa said:

Applying 'CoMOffset = 0.00037, 0, 0' to the Wolfhound seems to cause the CoM to align with the center of thrust on the bare engine.  However that that still doesn't change the off-center thrust at all, just helps quantify how much offset there is.  I guessed there might be a command CoTOffset (as there is CoMOffset and CoPOffset) but it had no effect.  I gather from reading other threads on creating engines that the thrust center may be baked in while creating the part in the Unity editor?

Anyone have other ideas on homegrown fixes?

AFAIK, the only fix is to replace the part model... same as with the vertically misaligned front and rear thruster quads on the MEM.  There's no fixing incorrect thrust origins after-the-fact through config-file edits.

If Squad doesn't replace the model, a modder could make a replacement model to substitute for Squad's model... like the way Ven's Stock Revamp replaces the stock parts with new models.

Edited March 31, 2018 by RoboRay

[Snark]

On 3/30/2018 at 3:48 PM, fourfa said:

I guessed there might be a command CoTOffset (as there is CoMOffset and CoPOffset) but it had no effect.

Yeah, that's because it's a different thing.  The CoM and CoP are purely config constructs-- there's nothing about them at all in the model, it's purely an in-game concept, so config can easily move it around.

Center of thrust, however, is baked into the model:  there's an actual "thrust transform" that's part of the model itself, and there's no way to move it around with config that I know of.  So basically it's unfixable without an update to the model.

1 hour ago, RoboRay said:

AFAIK, the only fix is to replace the part model... same as with the vertically misaligned front and rear thruster quads on the MEM.  There's no fixing incorrect thrust origins after-the-fact through config-file edits.

^ This.

1 hour ago, RoboRay said:

If Squad doesn't replace the model, a modder could make a replacement model to substitute for Squad's model... like the way Ven's Stock Revamp replaces the stock parts with new models.

Yep.  The problem is that it would put the onus on the modder to make an entirely new model from scratch, which would be a chunk of work.

[Sam Hall]

On 3/31/2018 at 5:26 PM, Snark said:

Yeah, that's because it's a different thing.  The CoM and CoP are purely config constructs-- there's nothing about them at all in the model, it's purely an in-game concept, so config can easily move it around.

Center of thrust, however, is baked into the model:  there's an actual "thrust transform" that's part of the model itself, and there's no way to move it around with config that I know of.  So basically it's unfixable without an update to the model.

Yeah pretty much. It wasn't exactly a picnic since i'm literally years outta practice doing unity editor stuff but I think I got it fixed. Used Taniwha's plugin to import the .mu files into Blender, welded up all the weird split edges that caused, snapped all the geometry and transforms to the center axis (almost everything on the Wolfhound was rotated exactly 1/10th of a degree off-center for some reason), then re-exported with Parttools. The resulting engines go in a nice straight line without the SAS having to lift a finger.

 

[Link snipped by moderator]

Two .mu files; put em in your  \GameData\SquadExpansion\MakingHistory\Parts\Engine\Assets folder. They'll overwrite LV-T91.mu and RE-J10.mu so don't forget to make backup copies of those  first. I don't think this should break anything, but like I said... literally years outta practice.

Edited April 3, 2018 by Snark
Violation of copyright

[RoboRay]

8 hours ago, Sam Hall said:

Two .mu files; put em in your  \GameData\SquadExpansion\MakingHistory\Parts\Engine\Assets folder. They'll overwrite LV-T91.mu and RE-J10.mu so don't forget to make backup copies of those  first. I don't think this should break anything, but like I said... literally years outta practice.

Very nice.  Assuming that Squad doesn't ever fix the problem officially, it might be worth writing a Module Manager patch to substitute your fixed versions for the originals (rather than overwriting them in the SquadExpansion folder) and just releasing them as a mod unofficial patch.

Maybe bundle in the various CoM fixes and other corrections with them.

Edited April 3, 2018 by RoboRay

[Snark]

11 hours ago, Sam Hall said:

Yeah pretty much. It wasn't exactly a picnic since i'm literally years outta practice doing unity editor stuff but I think I got it fixed.

Yes, it's technically doable.  What a pity that it's not legally possible for you to distribute your local fixes to anyone else, at all, because doing so would be violating Squad's copyright, same as if you'd just posted a pirated copy of Making History. 

Thus my earlier comment:

On 3/31/2018 at 5:26 PM, Snark said:

The problem is that it would put the onus on the modder to make an entirely new model from scratch, which would be a chunk of work.

I'm sorry, I know you mean well and you're only trying to help, so I hate to rain on your parade.  But repackaging and posting the game's commercial content is a major no-no, so I've had to snip your download link.

I dunno about you, but I've been really happy that thus far Squad has never put any sort of DRM on KSP.  Let's not go giving them reasons to regret and/or reconsider that decision, shall we? 

Please take your share down as soon as possible.  Thank you for your understanding.

2 hours ago, RoboRay said:

Assuming that Squad doesn't ever fix the problem officially, it might be worth writing a Module Manager patch to substitute your fixed versions for the originals (rather than overwriting them in the SquadExpansion folder) and just releasing them as a mod unofficial patch.

Unfortunately, @Sam Hall's fixed versions aren't legally distributable, which means ModuleManager can't help you. 

If simply moving the CoT were doable with ModuleManager, then this would be easily fixable with a simple MM tweak.  But it's not.  The only way to fix it is with a different model.  It's not okay to repackage Squad's models and distribute them, which means the choice comes down to either, 1. rebuild your own model completely from scratch so that it comes with no legal strings attached, or 2. wait for Squad to produce a fix.

I note that they've already fixed the Wolfhound with 1.4.2, so it seems to me that their intentions are clear-- Squad doesn't want broken parts out there any more than we do.  I'm not privy to their internal plans, of course, but I'd be surprised if 1.4.2 is the last 1.4 patch.  Perhaps just give it a little time and see what develops?

[Tyko]

On 4/3/2018 at 6:14 AM, Snark said:

I note that they've already fixed the Wolfhound with 1.4.2, so it seems to me that their intentions are clear-- Squad doesn't want broken parts out there any more than we do.  I'm not privy to their internal plans, of course, but I'd be surprised if 1.4.2 is the last 1.4 patch.  Perhaps just give it a little time and see what develops?

I don't think the Wolfhound is fixed in 1.4.2.  Are you saying there's a fix in for the next build that you're aware of? With 1.4.2 they centered the model under the stack, but the off-center thrust is still a problem.

[Snark]

On 4/4/2018 at 10:45 AM, Tyko said:

I don't think the Wolfhound is fixed in 1.4.2.  Are you saying there's a fix in for the next build that you're aware of? With 1.4.2 they centered the model under the stack, but the off-center thrust is still a problem.

Oh, it wasn't?  I was just going by the change notes that said something about "Wolfhound fixed" so assumed that was it.

(It's a bug I've never particularly noticed, myself, because the repro step is basically "turn off SAS in free-fall and burn", which is something I never have occasion to do.  I've found that the combination of SAS, plus reaction torque, plus the engine's gimbal, are enough that when I build a ship with a Wolfhound it flies pretty much as I expect it to, and I don't tend to notice any minor oddity around the edges.  Not making light of the bug here, just saying that I, myself, am not well equipped to notice it much one way or the other as it doesn't significantly affect my gameplay.)

As for any potential upcoming patches, and when they might be, and what they might fix, etc., we'll just have to wait and see.  I wouldn't be surprised if this sort of thing gets fixed, since it seems like a pretty straightforward kind of fix to make.  But that's just a guess, time will tell.

[Tyko]

1 hour ago, Snark said:

Oh, it wasn't?  I was just going by the change notes that said something about "Wolfhound fixed" so assumed that was it.

(It's a bug I've never particularly noticed, myself, because the repro step is basically "turn off SAS in free-fall and burn", which is something I never have occasion to do.  I've found that the combination of SAS, plus reaction torque, plus the engine's gimbal, are enough that when I build a ship with a Wolfhound it flies pretty much as I expect it to, and I don't tend to notice any minor oddity around the edges.  Not making light of the bug here, just saying that I, myself, am not well equipped to notice it much one way or the other as it doesn't significantly affect my gameplay.)

As for any potential upcoming patches, and when they might be, and what they might fix, etc., we'll just have to wait and see.  I wouldn't be surprised if this sort of thing gets fixed, since it seems like a pretty straightforward kind of fix to make.  But that's just a guess, time will tell.

The easiest way to repro is to use KER. create a new craft with just a fuel tank and the engine - this will activate the KER readout and you'll see that torque isn't zero which means there's some out-of-line force at work. Swap out the wolfhound for almost any other engine and torque will show as zero. 

I say "almost any engine" because the Cheetah is also out of whack. This KER test is one of the first things I do with any mod pack engines. It takes two seconds.

[Snark]

2 minutes ago, Tyko said:

The easiest way to repro is to use KER. create a new craft with just a fuel tank and the engine - this will activate the KER readout and you'll see that torque isn't zero which means there's some out-of-line force at work. Swap out the wolfhound for almost any other engine and torque will show as zero. 

I say "almost any engine" because the Cheetah is also out of whack. This KER test is one of the first things I do with any mod pack engines. It takes two seconds.

Oh, I believe you.  It's just that I don't actually use KER myself, so the only way I'd notice anything wrong is if it actually affects my gameplay in any significant way, which this one doesn't.

Not arguing that it doesn't need fixing, obviously it does.