Dragging Along

[Nate Simpson]

Good afternoon, Kerbonauts.

This week, we’re working on many of the same bugs we were working on last week (one aspect of our increased transparency is likely to be that you get to share in the joy of waiting for the oven to go "ding"). We did see some encouraging movement on a few items, but I’ll keep the original ten bugs on the list until we’ve got bona fide QA sign-off on them.

Bug Status
For most of this list, investigation and/or testing is ongoing. Areas that saw significant change have been marked in bold:

1. Vehicles in stable coasting orbits sometimes experience orbit instability/decay
   • Status: possible fix in progress
2. Trajectories change when vehicles cross SOI boundaries
   • Status: fix in progress
3. Certain inline parts cause aerodynamic drag numbers to spike
   • Status: fix being tested
4. Returning to craft from VAB causes craft to go underground (possibly related to Kerbals and landed vehicles dropping through terrain while being approached)
   • Status: possible fix being tested
5. Decoupling events result in various issues including loss of control, incorrect controllability of decoupled subassemblies, loss of camera focus, and other issues
   • Status: may have many causes, but some fixes in progress
6. Save files get bigger over time (TravelLog experiencing "landed" status spam)
   • Status: fix being tested
7. Opening part manager causes major frame lag
   • Status: experiments ongoing
8. Major post-liftoff frame rate lag immediately above launchpad (associated with engine exhaust lighting)
   • Status: fix being tested
9. Root parts placed below decouplers cause issues with stage separation
   • Status: under investigation
10. Vehicle joints unusually wobbly, some part connections unusually weak
    • Status: under investigation

Issue 2 - Trajectories change when vehicles cross SOI boundaries
We have three engineers looking at this and we have already ferreted out a couple of issues - the introduction of axial tilt to KSP2 introduced some discrepancies, and our SOI transit handoff math had some inconsistencies as well. A few other issues surfaced in the simulation code, and we’re assessing both the impact of those issues and the scope of work required to correct them.

Issue 3 - Certain inline parts cause aerodynamic drag numbers to spike
This bug is the one that saw the most movement this week. Our investigation of the spiking drag numbers revealed that we had a problem with drag occlusion — there is special code that reduces the frontal drag impact of a part that is blocked by another part, and in some cases we were seeing inline parts behave as though they weren’t shielded from airflow at all. In some cases, we were also seeing the opposite - wide parts that should have been creating drag were not having their frontal drag assessed at all. Of course, this latter case would rarely register as a problem, whereas the initial problem manifested in all sorts of unpleasant ways - essentially, parts positioned aft of other problem parts behaved like airbrakes, affecting both the overall drag and stability of the vehicle. Even weirder, these drag occlusion issues only arose when a vehicle was built horizontally!

This problem has been corrected. In fact, it’s been SO corrected that after we fixed it, we started to get messages from QA that aircraft felt too fast! We checked the numbers, and they’re correct. We’re still testing this fix, but it’s looking very good for the upcoming update. The details of how this problem was analyzed and corrected would make a very interesting dev diary from Chris Adderley, if he ever gets a few moments to spare.

Issue 8 - Major post-liftoff frame rate lag immediately above launchpad (associated with engine exhaust lighting)
Quick clarification: engines had previously each spawned a point light that cast shadows. While this was very pretty, it wasn’t great for performance (and this impact was increasingly pronounced at high engine counts). We have turned off shadow casting for those lights and are seeing an improvement in framerate near the launchpad.

Bug Reporting Progress
I also mentioned last week that we were exploring ways of communicating our current priorities more clearly, as well as giving members of the community more agency to communicate their own experiences and priorities to us. With that in mind, Dakota Callahan and the Community Team have begun to make some changes to the Suggestions and Development subforum. We’ll get into more detail about our specific implementation next week, but Dakota has already shown some of his work in that subforum - he’s taking several steps, including creating a new Bug Hunter member role, reformatting threads so that they can be up-/down-voted (this is just for bug threads), adding recommended tags/prefixes, and setting up a system that allows administrators to combine duplicate issues. This will start as a pilot program, and its success will hinge on how useful the community finds it and how maintainable our team finds it. The best possible outcome would be that players use the subforum to surface the issues they find most pressing, and our devs have the ability to ask directly for additional context. Again, I’ll provide more detail about this new structure when it’s fully in place, but in the meantime check out Dakota’s post - he’s got some great ideas!

Engines
After posting footage of the three new deep space methalox engines that will be arriving in update v.0.1.3.0, we’ve been asked by a few people what those engines can really do. Our Lead Producer Nestor Gomez (of KSP1 fame) suggested that we share some stats in the time-honored old-school way - with cool blueprint-style graphics!
Without further ado, here are the three new engines (with special thanks to Matt Poppe, who continues to do amazing work on everything he touches):

I have run a few missions with these engines, and I can attest that they’ve opened up quite a few new capabilities - ones that will become invaluable when the R + D progression enters the picture and nuclear thermal engines are not yet in reach.

Community Highlights
Last week, we did a space station challenge! Several of your impressive submissions can be seen over on our recent Community Highlights post. Some of this stuff is just nuts.

Check out this shot from <[I Flaze I]> on Discord:

Or how about this bad boy from HitchHacker:

I also really love this plane from spartandh211 (I’m a sucker for creative coloring tricks):

And then of course there’s a little sax-playing... cricket? From @The Space Peacock:

Be sure to check out that thread for even more fantastic creations. Thanks to all who submitted!

Weekly Challenge
This week’s challenge is technically about landing, though given Gilly’s low gravity, it might just as easily be called a docking challenge. Here are your goals:

• Primary goal: Land on Dock with Gilly
• Secondary goal: Dock with Gilly, plant a flag, and return safely to Kerbin
• Jeb-level goal: With just a jetpack, de-orbit from above Gilly, dock with Gilly, plant a flag, and return to your orbiting spaceship, then return to Kerbin
• Val-level goal: As above, but capture into the Eve system by aerobraking

Share your submissions over here on the forums  or over on Discord in #ksp2_challenges.

Good luck to you all, and see you next week!

[The Space Peacock]

8 minutes ago, Nate Simpson said:

And then of course there’s a little sax-playing... cricket? From @The Space Peacock:

I have to admit i’m very dissapointed by this upnate. This is obviously a Kerbug, shame on you Nate!!

 

Spoiler

(Just kidding, thanks for featuring our green buddy Greg! Hope you and the team have a great weekend)

 

[Spicat]

I was scared that you would not continue with bug fixes updates as the last post would be considered "sufficient" but I'm happy you are keeping this transparency from now on.

Edited June 2, 2023 by Spicat

[FlazeTheDragon]

lets goooo, the drag is finally being fixed!

[NovaRaptorTV]

Fantastic update! I cannot wait for the new engines to finally be put in! These engines look incredible, and the have fantastic performance. Seriously, you guy could not have picked a better base for these puppies, because the RL10 is a beast!

1 minute ago, Somecallmesteve said:

Fantastic update! I cannot wait for the new engines to finally be put in! These engines look incredible, and the have fantastic performance. Seriously, you guy could not have picked a better base for these puppies, because the RL10 is a beast!

*guys, lol

[Vortygont]

Glad to hear that you are making great progress in fixing the drag problems. I really want to build a ssto with cargo bays, but they had drag issues 

[Scarecrow71]

56 minutes ago, Nate Simpson said:

Issue 2 - Trajectories change when vehicles cross SOI boundaries
We have three engineers looking at this and we have already ferreted out a couple of issues - the introduction of axial tilt to KSP2 introduced some discrepancies, and our SOI transit handoff math had some inconsistencies as well. A few other issues surfaced in the simulation code, and we’re assessing both the impact of those issues and the scope of work required to correct them.

To hear that you have 3 people working on this AND it's crossing through multiple areas of the code (axial tilt, SOI hand-off, etc.) is both disappointing and encouraging.  Disappointing that it's so deep in the code that it may take several more patches before it is fixed, but encouraging because you guys are hard at work in identifying where it lies and how to go about fixing it.

And thank you for the continued communication; the transparency is most welcome.  Only question I have now, that won't get answered for a while, is...when is the next patch coming?

[Darrin H]

Hi everyone,

I’m super biased, but this part of the Dev Update is the most important part (to me)!

Please read it over, check out the hyperlink to Dakotas post for feedback… and give feedback!   It’ll be a pilot program initially and we’ll DEFINITELY make changes over time, but this was a big request from my QA blog, and this is our first big process change in that regards.   

This is that opportunity everyone wants: to impact change in how we do things…!

thanks,

Darrin.

 

Bug Reporting Progress
I also mentioned last week that we were exploring ways of communicating our current priorities more clearly, as well as giving members of the community more agency to communicate their own experiences and priorities to us. With that in mind, Dakota Callahan and the Community Team have begun to make some changes to the Suggestions and Development subforum. We’ll get into more detail about our specific implementation next week, but Dakota has already shown some of his work in that subforum - he’s taking several steps, including creating a new Bug Hunter member role, reformatting threads so that they can be up-/down-voted (this is just for bug threads), adding recommended tags/prefixes, and setting up a system that allows administrators to combine duplicate issues. This will start as a pilot program, and its success will hinge on how useful the community finds it and how maintainable our team finds it. The best possible outcome would be that players use the subforum to surface the issues they find most pressing, and our devs have the ability to ask directly for additional context. Again, I’ll provide more detail about this new structure when it’s fully in place, but in the meantime check out Dakota’s post - he’s got some great ideas!

[Acid_Burn9]

1 hour ago, Nate Simpson said:

Issue 3 - Certain inline parts cause aerodynamic drag numbers to spike
This bug is the one that saw the most movement this week. Our investigation of the spiking drag numbers revealed that we had a problem with drag occlusion — there is special code that reduces the frontal drag impact of a part that is blocked by another part, and in some cases we were seeing inline parts behave as though they weren’t shielded from airflow at all. In some cases, we were also seeing the opposite - wide parts that should have been creating drag were not having their frontal drag assessed at all. Of course, this latter case would rarely register as a problem, whereas the initial problem manifested in all sorts of unpleasant ways - essentially, parts positioned aft of other problem parts behaved like airbrakes, affecting both the overall drag and stability of the vehicle. Even weirder, these drag occlusion issues only arose when a vehicle was built horizontally!

This problem has been corrected. In fact, it’s been SO corrected that after we fixed it, we started to get messages from QA that aircraft felt too fast! We checked the numbers, and they’re correct. We’re still testing this fix, but it’s looking very good for the upcoming update. The details of how this problem was analyzed and corrected would make a very interesting dev diary from Chris Adderley, if he ever gets a few moments to spare.

Thank you <3

I've been hoping this one gets adressed ASAP. I can finally have fun with planes!

[Chevronie]

Quote

I also really love this plane from spartandh211 (I’m a sucker for creative coloring tricks):

hey, the X-02 Wyvern from Ace Combat! I've recently become a sucker for ace combat and this was a very surprising thing to see on the ksp2 dev blog

Cant tell if this is the highlight of this post or the news of my biggest issues ive encountered in game are actively being worked on

[wasml]

Really like the new format - I know the it doesn't make the bug fixing go any faster but it's easier to see the progress with weekly peeks behind the curtains vs. once every 4-8 weeks when we get an update. As someone who codes I also find interesting the explanation of the problems you uncover.

Thanks! and keep up the good work - looking forward to the next patch.

[The Aziz]

I'm only curious whether those top priority bugs are all scheduled for next patch, or given their current status, some may be still left for the patch after that (or even later)? I know there's no timeline on 0.1.3 right now but how likely it is that the patch will wait until all of those are fixed completely or at least partially?

Edited June 2, 2023 by The Aziz

[Davidian1024]

2 hours ago, Nate Simpson said:

we started to get messages from QA that aircraft felt too fast

Yes please

[Kavaeric]

I concur with the increased bug transparency, if only to sate my own curiosity of how the sausage is made.

Having seen the new engine stats here, it would be interesting to get further insight into how the new archetypes of vacuum engine (devlog #17) are balanced and find their niche--I imagine it's more than just deep space engines being even more efficient than their orbital counterparts

[Kerbart]

A post like this gives more confidence in the game than a ten minute video about the new engine. Thank you!

[Dakota]

39 minutes ago, wasml said:

I also find interesting the explanation of the problems you uncover.

more to come soon(tm)

[Pthigrivi]

Love you Nate and team! Thank you all so much for sticking in this. I'm sure it can be discouraging at times but I believe in you all. 

[SethM]

yayyy!  the new engines look spectacular .  looking forward to the next patch Nate!  

[Sylvi Fisthaug]

1 hour ago, Scarecrow71 said:

when is the next patch coming?

June  

[pbau5]

Honest question, how are people completing these "return to Kerbin" objectives with the SOI trajectory issue... and staying sane?

Edited June 2, 2023 by pbau5

[Spicat]

6 minutes ago, pbau5 said:

Honest question, how are people completing these "return to Kerbin" objectives with the SOI trajectory issue... and staying sane?

Eyeballing it or doing a maneuver outside of the planet SOI

Edited June 2, 2023 by Spicat

[whatsEJstandfor]

11 minutes ago, pbau5 said:

Honest question, how are people completing these "return to Kerbin" objectives with the SOI trajectory issue... and staying sane?

Lots and lots of quicksaves, and trial and error.

[herbal space program]

Thank you Nate for that thorough and transparent update about all the bugs! I'm especially excited about fixing the drag issues with SSTOs, as I've been working on making one for a Jool5 Laythe lander,  and they definitely seem a lot draggier in this version of KSP2 than they were in the later versions of KSP1. It's somewhat made up for by the fact that engines seem to lose thrust significantly more slowly with altitude in KSP2 than they did in KSP1, but still I seem to be getting about the performance at 10 tons per RAPIER or Whiplash that I was getting at 15 tons per jet engine in KSP1.

Edited June 2, 2023 by herbal space program

[LunarMetis]

3 hours ago, Nate Simpson said:

Issue 8 - Major post-liftoff frame rate lag immediately above launchpad (associated with engine exhaust lighting)
Quick clarification: engines had previously each spawned a point light that cast shadows. While this was very pretty, it wasn’t great for performance (and this impact was increasingly pronounced at high engine counts). We have turned off shadow casting for those lights and are seeing an improvement in framerate near the launchpad.

Hope this bug fix makes it to this month's patch, and it's a very welcome one for me since this bug was among the ones that bothered me the most. The fact that this seems to be a relatively simple (at least I'd imagine it to be) one to fix gives me a little more hope. Keep at it, guys!

[Nightside]

If the upcoming release can manage to  decrease the min spec a little bit  I'll finally hit SPACE on buying the game. 

Not expecting a finished game, but would like to check it out  if a 6-year-old rig can handle it.