UmbralRaptop changed the topic of #principia to: READ THE FAQ: http://goo.gl/gMZF9H; The current version is Fuchs. We currently target 1.5.1, 1.6.1, 1.7.x, 1.8.1, and 1.9.1. <scott_manley> anyone that doubts the wisdom of retrograde bop needs to get the hell out | https://xkcd.com/323/ | <egg> calculating the influence of lamont on Pluto is a bit silly… | <egg> also 4e16 m * 2^-52 is uncomfortably large
<discord->
Conventia. — The only thing that confuses me about Principia is that the orientation of the navball in some frames of reference doesn't make sense.
<discord->
egg. — it does make sense, but you have to learn what the navball represents
<discord->
Conventia. — That's what I intended to say. 😛
<discord->
egg. — really the surface frame is the odd one
<discord->
egg. — all the others work in the same way
<discord->
lpg. — it took me forever for the _stock_ navball to make sense
<discord->
Conventia. — It's definitely a "I haven't learned this yet". I'm just not sure if it's also a "Principia doesn't teach this well" or a "I don't learn this well", yet.
<discord->
egg. — yeah the surface frame is the stock navball
<discord->
egg. — (effectively)
<discord->
Conventia. — That's the primary one that makes sense to me.
<discord->
egg. — @Conventia Principia doesn't do much teaching, but it does come with a bit of documentation
<discord->
Conventia. — Maybe my brain has been damaged by stock.
<discord->
Conventia. — By teaching, I mostly meant through using something enough that it becomes familiar/intuitive.
<discord->
egg. — ah
<discord->
egg. — well, one way to think about it is that the navballs don't rotate in map view
<discord->
egg. — (except the surface one which is weird)
<discord->
Conventia. — My first time doing a TLI, I played with the various reference frames and they made sense by the time I did it the third time.
<discord->
egg. — i.e., if you have a nonrotating reference frame, the navball is fixed with respect to the fixed stars
<discord->
Conventia. — That's not happening with the navball orientation. 😛
<discord->
Conventia. — And I read the Concepts page, I'm pretty sure.
<discord->
egg. — if you have ECSA (which I really should rename one of these centuries), the navball rotates as does the Earth around the Sun
<discord->
egg. — in other words, it is fixed in the ECSA reference frame
<discord->
egg. — aligned with the Sun-Earth axis and the orbital plane
<discord->
egg. — no matter where you are
<discord->
egg. — now that the camera turns with the plotting frame, that really means that as you see things in map view, the navball doesn't turn
<discord->
egg. — (that is how the Apollo ball worked IIRC, it retained an inertially fixed orientation)
<discord->
Conventia. — Ah, I guess that helps.
<discord->
egg. — @Conventia actually now that we turn the camera in map view it should be really nice, because it really exactly maps to map view: if you point up on the navball, you point up in map view
<discord->
egg. — if you point on the reference plane, you are horizontal in map view
<discord->
egg. — etc.
<discord->
egg. — (we should probably update the concepts page to say so)
<discord->
Conventia. — What do you mean by 'turn the camera in map view'?
<discord->
egg. — I mean that the camera doesn't move in the plotting frame
<discord->
Conventia. — Don't I 'turn the camera' in all view?
<discord->
egg. — no but we do beneath you as well
<discord->
Conventia. — Don't I 'turn the camera' in all views? (edited)
<discord->
egg. — look at Kerbin in KCKF in map view
<discord->
egg. — you will see that Kerbin does not rotate
<discord->
egg. — the camera always points at the same place on Kerbin
<discord->
egg. — instead, the world rotates around the camera
<discord->
Conventia. — I've never used Principia with stock 😛
<discord->
egg. — well s/Kerbin/Earth/g then
<discord->
Conventia. — 😛
<discord->
egg. — if you used Principia before Fréchet you might remember a time when the plotted trajectories would move around in map view, because the camera did not move with the plotting frame
<discord->
egg. — now, the camera agrees with the navball
<discord->
Conventia. — So, it's like pressing V in flight and selecting the locked camera?
<discord->
egg. — kind of? except it is locked to the reference frame
<discord->
Conventia. — I can then control what I'm looking at, but the vessel moving makes the camera move.
<discord->
egg. — yeah, locked to Earth's surface in the Surface frame, locked to the Earth-Sun line and orbital plane in ECSA, etc.
<discord->
Conventia. — Well, yeah, the vessel is the reference frame analog.
<discord->
egg. — and in fact this even happens in the target frame, so then it is locked to the Target-Planet line and orbital plane
<discord->
egg. — actually you can experience that easily
<discord->
egg. — look at Earth, select ECI, then switch to Uranus-Centred Inertial
<discord->
egg. — the world will tilt as the camera horizontal becomes Uranus's equator
<discord->
egg. — and that is also the new navball horizontal
<discord->
Conventia. — You're wanting to test my motion sickness tolerance, aren't you?
<discord->
egg. — well, you can try ECI vs. ECSA for something milder
<discord->
egg. — that will tilt by Earth's axial tilt
<discord->
Conventia. — I've never felt motion sick playing a game until my X-8 started flipping and I locked the camera too it so I could calmly check the RCS for whether they were on. After about 2 minutes, I'm like... ok, done checking now, switch to a different view.
<discord->
egg. — hah
<discord->
Conventia. — It happened slowly enough that I could actually think about it and realize that I should just stop the motion rather than try to let my brain figure it out.
egg|laptop|egg has quit [Remote host closed the connection]
egg|cell|egg has joined #principia
raptop is now known as ObservatoryRaptop
Mike` has quit [Ping timeout: 190 seconds]
Mike` has joined #principia
egg|laptop|egg has joined #principia
Wetmelon has quit [Ping timeout: 190 seconds]
egg|laptop|egg has quit [Ping timeout: 378 seconds]
egg|cell|egg has quit [Ping timeout: 204 seconds]
egg has quit [Read error: Connection reset by peer]
egg has joined #principia
egg|cell|egg has joined #principia
Wetmelon has joined #principia
egg|cell|egg has quit [Ping timeout: 378 seconds]
Wetmelon has quit [Ping timeout: 189 seconds]
egg|cell|egg has joined #principia
egg|laptop|egg has joined #principia
<_whitenotifier-d13c>
[Principia] formicant forked the repository - https://git.io/JfyGl
ObservatoryRaptop is now known as raptop
egg|anbo|egg has joined #principia
raptop has quit [Ping timeout: 204 seconds]
<discord->
Damien. — the child centered parent aligned frames are really useful for launching into plane. one of the best features imo
<discord->
Damien. — the child centered parent aligned or barycentric frames are really useful for launching into plane. one of the best features imo (edited)
<discord->
egg. — yeah it is a good frame
<discord->
Damien. — is it possible to have tooltips for the different frame descriptions? I've noticed a lot of newer players trying principia and some noob friendly text explaining what each frame does would be useful
<discord->
egg. — well, we have a wall of text in the UI already
<discord->
egg. — if you have suggestions for better words we could tweak that
<discord->
Damien. — yeah you do but it's egg-speak
<discord->
Damien. — I'll have a think
<discord->
Damien. — I think the description in noob-speak could end up being longer than the text you already have though so that's why I said a tooltip
<discord->
Damien. — something they could mouseover and get an explanation
<discord->
egg. — at some point improving the documentation might be the way to go
<discord->
Damien. — yeah that's fair
<discord->
egg. — it is definitely not very helpful
<discord->
egg. — because it is written by people who do not play
<discord->
Conventia. — You don't play?
<discord->
Damien. — lol here we go
<discord->
egg. — there are only so many hours in a day, can't play *and* develop the mod,
<discord->
Conventia. — (I mean... writing the mod is like playing... sort of)
<discord->
egg. — it is much better, it does not involve starting KSP
<discord->
Conventia. — That's why I don't want to try installing RO/RP-1 from master. The last time I did that, I started developing it more than playing it.
<discord->
Damien. — I understood egg a lot better when I realised that making interesting principia features is how egg enjoys ksp
<discord->
Damien. — I understood egg a lot better when I realised that making interesting principia features is how he enjoys ksp (edited)
<discord->
Conventia. — I just learned that it's mostly written in C++. I didn't know that.
<discord->
Conventia. — I don't know how people who write mostly patches do it. Not having MM's cache to make startup faster is really annoying.
<discord->
siimav. — Cache doesn't make a very significant difference for a minimalistic install. Loading the assets will take up almost as much time as putting the MM cache together.
<discord->
siimav. — And sometimes you can also edit the cache directly
egg|laptop|egg has quit [Remote host closed the connection]
egg|cell|egg has quit [Ping timeout: 190 seconds]
<discord->
Damien. — @egg going back to tooltips, I'm thinking of a very high level, easy to understand explanation of what the frames do. Just expanding on the description you have. This may not be 100% accurate so feel free to correct anything.
<discord->
Damien. — The line between Earth and the Moon is fixed.
<discord->
Damien. — Moon is fixed.
<discord->
Damien. — Earth moves back and forth as its distance from the Moon changes.
<discord->
Damien. — Navball midline is orbital plane of Moon around Earth.
<discord->
Damien. —
<discord->
Damien. — Used for:
<discord->
Damien. — Earth-Moon Transfers.
<discord->
Damien. — Earth-Moon Lagrange Point Orbits.
<discord->
Damien. — Launching into plane with the Moon.
<discord->
Damien. — ---------------------------
<discord->
Damien. —
<discord->
Damien. — Earth Centred Sun Aligned (ECEA)
<discord->
Damien. —
<discord->
Damien. — In this frame:
<discord->
Damien. — The line between the Sun and Earth is fixed.
<discord->
Damien. — @egg going back to tooltips, I'm thinking of a very high level, easy to understand explanation of what the frames do. Just expanding on the description you have. This may not be 100% accurate so feel free to correct anything.
<discord->
Damien. — The line between Earth and the Moon is fixed.
<discord->
Damien. — Moon is fixed.
<discord->
Damien. — Earth moves back and forth as its distance from the Moon changes.
<discord->
Damien. — Navball midline is orbital plane of Moon around Earth.
<discord->
Damien. —
<discord->
Damien. — Used for:
<discord->
Damien. — Earth-Moon Transfers.
<discord->
Damien. — Earth-Moon Lagrange Point Orbits.
<discord->
Damien. — Launching into plane with the Moon.
<discord->
Damien. — ---------------------------
<discord->
Damien. —
<discord->
Damien. — Earth Centred Sun Aligned (ECEA)
<discord->
Damien. —
<discord->
Damien. — In this frame:
<discord->
Damien. — The line between the Sun and Earth is fixed.
<discord->
Damien. — @egg going back to tooltips, I'm thinking of a very high level, easy to understand explanation of what the frames do. Just expanding on the description you have. This may not be 100% accurate so feel free to correct anything.
<discord->
Damien. — well it sounds cool anyway even though I don't really understand it
<discord->
Conventia. — That's how I feel.
<discord->
Damien. — that's principia all over
<discord->
Conventia. — I looked up ballistic captures and I saw the animation for GRAIL and I asked myself... "I wonder what reference frame that tiny animation is in?"
<discord->
Conventia. — That's when I realized that egg succeeded.
<discord->
Damien. — @egg going back to tooltips, I'm thinking of a very high level, easy to understand explanation of what the frames do. Just expanding on the description you have. This may not be 100% accurate so feel free to correct anything.
<discord->
Damien. — I haven't done the genesis mission yet. Just planned the trajectory to work out dv requirements
<discord->
Damien. — I need to design the right spacecraft first
<discord->
Damien. — the solar wind collection part and the return capsule part are pretty chonk
<discord->
Conventia. — eggceptional!
<discord->
Conventia. — Now I feel dirty.
<discord->
Damien. — 🦾 🥚
<discord->
Conventia. — And on the playing vs developing for KSP... you know your successful at writing a piece of software when someone else uses it more than you do.
<discord->
Conventia. — Oh, random amusing Principia related thing. I lost a lunar probe due to the orbit being too low (well, this was after it collected all the science, so it was worth it, after all). It's just refreshing to click on the kerbalism window and realize that where there were two probes, there is now one.
<kmath>
YouTube - Stock KSP Career w/ Principia - Interplanetary
<discord->
Damien. — ECI and VCSA will do the job
<discord->
Damien. — then VCI to fine tune your capture
<discord->
Conventia. — I see.
<discord->
Conventia. — Thanks
<discord->
egg. — @Myshiko I recommend the papers of Lara on this subject https://forum.kerbalspaceprogram.com/index.php?/topic/162200-wip151-161-17x-181-principia%E2%80%94version-fuchs-released-2020-05-22%E2%80%94n-body-and-extended-body-gravitation-axial-tilt/page/59/&tab=comments#comment-3742186
<discord->
egg. — in particular because this shows you that there are stable configurations for most inclinations at all semimajor axes, which is generally overlooked
<discord->
egg. — (the allowed inclinations of stable orbits at a given semimajor axis only become discrete if you require circular orbits)
<discord->
Conventia. — How close is good enough for the first burn? 200Mm?
<discord->
Conventia. — I think I might have launched into the wrong plane. I think I'll try again tomorrow. (I also forgot to accept the contract.)
Wetmelon has quit [Ping timeout: 189 seconds]
egg|cell|egg has joined #principia
egg|cell|egg has quit [Ping timeout: 378 seconds]
egg|cell|egg has joined #principia
egg|laptop|egg has joined #principia
raptop has joined #principia
egg|laptop|egg has quit [Remote host closed the connection]
egg|laptop|egg has joined #principia
egg|laptop|egg has quit [Remote host closed the connection]
egg|cell|egg has quit [Read error: Connection reset by peer]
egg|cell|egg has joined #principia
Jesin has quit [Quit: Leaving]
Jesin has joined #principia
<discord->
Julexus Quandem. — Can I have a bit of advice on getting to Mars, pretty sure I got quite close once but don't seem to be able to do it again. Which is the best manoeuvring frame selection? I think I've got a good window, though I'm in 1967 and no one actually went in that window, which has me wondering if it was no good for some reason?
egg|laptop|egg has quit [Remote host closed the connection]
egg|laptop|egg has joined #principia
egg|laptop|egg has quit [Remote host closed the connection]
<discord->
egg. — @Damien @lpg I am trying to think of ways to make the orbit analyser easier to use, in particular with an eye towards putting it in the flight plan. Right now the primary is coupled to the selected body for the plotting frame; is that useful? If that coupling is not useful, should we instead autodetect what the correct primary may be?
<discord->
egg. — also @Butcher if you have analyser thoughts
<discord->
Butcher. — What are the current plans, if any?
<discord->
egg. — well, I was thinking of doing primary autodetection, and then orbit analysis of the last coast of the flight plan
<discord->
egg. — otherwise the analysis would be tied to how you look at the plan, but since the plan contains more than just the final orbit that would get obnoxious I think
<discord->
egg. — (could also analyse the other coasts, to say "here you are on a parking orbit with those properties")
<discord->
egg. — (and then piggyback on that to have a +1 synodic rev. mechanism for moving burns, sometime in the distant future)
<discord->
egg. — so that interplanetary planning finally becomes sane
<discord->
Butcher. — How does that analyser help interplanetary planning?
<discord->
Butcher. — We are talking about the window with many numbers correct?
<discord->
egg. — yes
<discord->
egg. — so, first, having it in the last coast helps you with figuring out how you are going to change the numbers instead of having to fly by the seat of your pants to see what the numbers do
<discord->
egg. — having it in intermediate coasts allows us to have a definition of "revolution", so that we could have a "move this burn to the next revolution" button (likely for synodic revolutions wrt the parent)
<discord->
egg. — i.e., move the manoeuvre in time at constant ejection angle
<discord->
Butcher. — Oh that would be very handy. While you're at it, snap manoeuvre to apsis.
<discord->
egg. — no that is a completely different can of worms which is largely ill-defined
<discord->
Butcher. — 😆
<discord->
Butcher. — You mean a "challenge".
<discord->
egg. — but the +1 rev. stuff would be far down the line
<discord->
egg. — first would be orbit analysis of the final coast of the flight plan
<discord->
Butcher. — Snap manoeuvre to soi change. 😄
<discord->
egg. — that is supremely useless,
<discord->
egg. — "what kind of orbit will I get", rather than "what kind of orbit am I on" which the current analysis tells you
<discord->
egg. — anyway, does anyone have thoughts on the question I asked initially
<discord->
egg. — has anyone used the analyser at all
<discord->
lpg. — As for myself, barely. Not sure I've used it for anything other than giving multiple satellites the same period
<discord->
Butcher. — I've used it to check orbit stability a bit, but not much.
<discord->
Damien. — I've glanced at it to make sure what I was looking at made sense (nodal precession, orbital period etc) but not really used it more than that
<discord->
Damien. — which is a shame because it clearly does what it does well, but in a lot of usage cases in ksp the mk1 eyeball does a passable job
<discord->
Damien. — being able to set the entity (craft/body) and its parent would make it a lot more useful imo but that's already been discussed
<discord->
Damien. — ie 'what is the moon's inclination relative to the earth'
<discord->
egg. — not quite sure what the use of that is
<discord->
Damien. — telling PVG what inclination to launch into
<discord->
egg. — yeah OK that is a bit niche
<discord->
egg. — interesting, but not in and of itself a reason to work at something for the next few months
<discord->
egg. — would there be any use for analysis of the planned orbit?
<discord->
egg. — or would I be building yet another feature no-one cares for
<discord->
Damien. — possibly but not that comes to mind right now
<discord->
egg. — i.e. "does this burn get me to GEO"
<discord->
egg. — (or rather "how close to GEO is it, and what happens if I tweak it)
<discord->
egg. — (or rather "how close to GEO is it, and what happens if I tweak it") (edited)
<discord->
lpg. — "what is the moon's inclination relative to the earth" is the sort of case where asking MJ will give you a plenty-good answer
<raptop>
"It depends"
<discord->
Damien. — I've always avoided trusting MJ when it comes to stuff like that because of early attempts to launch into plane being hilariously wrong
<discord->
Damien. — that's probably just me though
<discord->
Butcher. — I've used KER to get relative inclination, it seems fine.
<discord->
Damien. — I literally use it for ascent to orbit only and explicitly tell it what inclination to launch to
<discord->
Damien. — that's it
<discord->
lpg. — I can definitely see a usefulness for, say, being able to plan a resonant orbit. It's not just a scenario _I_ run into
<discord->
lpg. — I can definitely see a usefulness for, say, being able to plan a resonant orbit. It's just not a scenario _I_ run into (edited)
<discord->
Butcher. — The keplerian elements are close enough there.
<discord->
Damien. — as you say @egg there could be things that sound cool and if you could click your fingers and have it appear would be nice, but it needs a lot more discussion of actual usage cases that would be worth the effort to build
<discord->
Damien. — I can't think of much (probably because it's midnight on a school night) but I'll have a think
<discord->
Damien. — it doesn't help that I've not been playing much recently
<discord->
egg. — well, ultimately the primary driver here is not so much usage as the implementation being interesting
<discord->
egg. — but it is nice if it serves some purpose, all other things being equal
<discord->
egg. — for instance, would any of you have some use for a sun-synchronicity report in the analyser?
<discord->
egg. — iirc that one is hard to eyeball usefully
<discord->
Damien. — definitely
<discord->
Damien. — that's come up before
<discord->
egg. — hm
<discord->
Damien. — if the orbit analyser gave stats based on your flight plan that would be really interesting to me but I can imagine the can of worms regarding plotting frame, which bodies to measure between etc etc
<discord->
egg. — nah but that is why I have that original question
<discord->
egg. — an orbit is typically an orbit of one thing at a time
<discord->
egg. — in weird cases we fail to detect an orbit
<discord->
egg. — so we may be able to autodetect the primary
<discord->
Damien. — yeah I could definitely see that being useful
<discord->
Damien. — as it is I use the analyser as a 'my orbit looks right, but let me check the fine print to be sure' tool
<discord->
egg. — the sun-synch stuff sounds useful has been a vague plan for ages, but it requires analysing arbitrary trajectories (so as to analyse those of the celestials) which requires proper quadrature, which requires more integrators, so that will take a few months
egg|laptop|egg has joined #principia
egg|cell|egg has quit [Read error: Connection reset by peer]