Need clarification about connection points and attaching parts

[Celthon]

I've had the game less than two weeks, so mostly do not know what I'm doing...playing career mode, desktop PC, without mods or add-ons...as I build things I am careful to attach parts on the green/black indicators for "connection points"...but as I have been browsing through you-tube videos and guides I have noticed that many people are building things in which they move parts using the move and/or rotate tools, in some cases moving the parts what appears to me to be a significant distance from the original point it snapped onto.  My questions and/or confusions:

> Does the game's coding or mechanics or whatever you call the 'behind-the-scenes" part of the game not care where/how a part is attached to another part?

> Are parts that have been 'edited' (rotated/moved from the original snap-to point) more prone to fall off, break or in some other way fail?

> If the parts have been moved (and to my thinking "misaligned") with the move and/or rotate tools, are angles, thrust lines, lifting surfaces, etc., affected, causing a craft to behave in unexpected ways or to respond to control inputs differently than expected?

> If none of this matters, what is the point of the green/black connection points...I was operating from the assumption it is where the parts have to be attached, to be attached 'correctly'...it's very possible I did not read something correctly or entirely in the beginning and have been operating with incomplete information.

It seems that the vast majority of people using this game are playing a version that barely resembles the original game, due to all the mods and add-ons being used...so when I watch someone showing how they build xyz craft or abc plane is it probably possible because of the mods and add-ons, and it's not mentioned in the video because they presume "everybody does it" (uses mods and add-ons)? 

I linked a video below as an example of the "moving/turning" I am asking about -- at approx. 0:15 in the video he attaches three antenna then rotates/moves them and the end result is that the attachment points of the three antenna now appear as one item with three faces.

I apologize if I'm breaking some rule by posting his video as an example...I do not intend to indicate that he's doing anything wrong or cast him nor the video in a negative light...I'm just using it as an exemple and asking for clarification about how the game's "engine" or coding or whatever it's called treats these types of edited connections in regards to aerodynamics, thrust lines and forces applied to the parts -- in the case of this example would the antennas more easily break-off when going through an atmosphere at speed since they are no longer attached to the original green/black connection point? 

Thank you for your time and assistance.

https://www.youtube.com/watch?v=NzqVfjlsb7U

[Gargamel]

Moved to Gameplay Q's, and the video link appears to be fine, as long as it doesn't contain profanity or anything else prohibited by our rules. 

 

 

[Superfluous J]

10 minutes ago, Celthon said:

I've had the game less than two weeks, so mostly do not know what I'm doing...playing career mode, desktop PC, without mods or add-ons...as I build things I am careful to attach parts on the green/black indicators for "connection points"...but as I have been browsing through you-tube videos and guides I have noticed that many people are building things in which they move parts using the move and/or rotate tools, in some cases moving the parts what appears to me to be a significant distance from the original point it snapped onto.  My questions and/or confusions:

I'll do my best

10 minutes ago, Celthon said:

> Does the game's coding or mechanics or whatever you call the 'behind-the-scenes" part of the game not care where/how a part is attached to another part?

If you attach two things via their nodes, then there is a single-point connection at that node. If you attach things radially, there is a single point connection from the center of the attached part, to where you placed it radially on the other part. outside of struts and fuel lines, there is no other way to attach things. Hopefully this answered your question enough. If you've still got questions, feel free to continue asking them.

10 minutes ago, Celthon said:

> Are parts that have been 'edited' (rotated/moved from the original snap-to point) more prone to fall off, break or in some other way fail?

No. In fact, they're still considered by many game functions to be still attached where you originally put them. Though not in all cases. As above, they're still attached to each other from the same point on each craft, but if you put a force on one of the parts it will apply torque to the other part differently depending on how you shifted it.

10 minutes ago, Celthon said:

> If the parts have been moved (and to my thinking "misaligned") with the move and/or rotate tools, are angles, thrust lines, lifting surfaces, etc., affected, causing a craft to behave in unexpected ways or to respond to control inputs differently than expected?

They are affected. Drag is affected differently (aka incorrectly) but thrust will behave like you'd expect looking at it. I can't speak on lifting surfaces because planes flummox me in general so I just avoid them. Except in some crazy situations, control inputs should "just work." If you have a craft that doesn't, I'd suggest asking about that craft in particular.

10 minutes ago, Celthon said:

> If none of this matters, what is the point of the green/black connection points...I was operating from the assumption it is where the parts have to be attached, to be attached 'correctly'...it's very possible I did not read something correctly or entirely in the beginning and have been operating with incomplete information.

The connection points are a snap-to to make everything line up. If you had to attach everything the same way you attach radial parts, then no ship would be perfectly lined up when you put 8 same-sized fuel tanks together. Also, they actually do create a more secure connection, the bigger those spheres are (matching generally to the cross sectional width of the part). 5 meter tanks do actually hold together with more oomph than 0.625 meter tanks, if you attach them with those nodes.

10 minutes ago, Celthon said:

It seems that the vast majority of people using this game are playing a version that barely resembles the original game, due to all the mods and add-ons being used...so when I watch someone showing how they build xyz craft or abc plane is it probably possible because of the mods and add-ons, and it's not mentioned in the video because they presume "everybody does it" (uses mods and add-ons)? 

I use a lot of mods, but almost exclusively stick to stock parts. Of course, I've not really posted YouTube videos consistently for ... gee has it really be YEARS? Yes. Yes it has.

10 minutes ago, Celthon said:

I linked a video below as an example of the "moving/turning" I am asking about -- at approx. 0:15 in the video he attaches three antenna then rotates/moves them and the end result is that the attachment points of the three antenna now appear as one item with three faces.

I'm not a moderator so can't say if you're breaking a rule or not but I don't think so. However, I'm not in a position to watch videos right now so will not address this point.

[bewing]

I'll try to answer independently from 5th Horseman, just in order to confuse you more with slightly conflicting information.

Quote

> Does the game's coding or mechanics or whatever you call the 'behind-the-scenes" part of the game not care where/how a part is attached to another part?

Yes and no. The game forms an attachment from the new part to the CoM of the part you attach it to. Forces on each part are communicated to each other through this attachment. The attachment acts as a radial arm that converts a force into a torque in a physically correct way. The game is designed specifically to give you great flexibility in building your craft for functional or aesthetic purposes. It is designed to model your craft as accurately as conveniently possible, no matter how you tweak it using the editing tools.

Quote

> Are parts that have been 'edited' (rotated/moved from the original snap-to point) more prone to fall off, break or in some other way fail?

No and yes. The farther you move a part away from the CoM of its parent part, the larger that any resulting torque from an impacting force will be. Each attachment has a maximum torque for failure. But you aren't supposed to be running your craft into things, so you aren't supposed to be getting impact forces on your craft, so parts are not supposed to fall off in general -- unless you have accomplished something in KSP called an "oops". Besides torques, no, a part that has been moved/rotated works just like normal.

Quote

> If the parts have been moved (and to my thinking "misaligned") with the move and/or rotate tools, are angles, thrust lines, lifting surfaces, etc., affected, causing a craft to behave in unexpected ways or to respond to control inputs differently than expected?

Yes, the angles and aerodynamics are affected. But it is in fact necessary to rotate some parts (the communotron 16s antenna for example) to minimize drag. Or to give wings a built-in angle of attack. Or to rotate or move other parts around in your craft to make them accessible from the ground or when you are on a ladder or standing on top of the craft, etc. etc. So "misaligned" might not be an accurate mental concept. Yes, behavior and control input can change -- but it's mostly very logical and consistent and physically accurate about how it changes. So whether it's "different than expected" depends on your expectations now, doesn't it?

Quote

> If none of this matters, what is the point of the green/black connection points...I was operating from the assumption it is where the parts have to be attached, to be attached 'correctly'...it's very possible I did not read something correctly or entirely in the beginning and have been operating with incomplete information.

The green ones are called "stack nodes". Many parts only attach on stack nodes. All other parts are called "radially attachable" parts. You can generally stick them on anywhere you like. There is a button in the editor that looks like either a hexagon or a circle. Have you ever tried clicking that into "circle" mode? In hexagon mode it's called "angle snap" -- in angle snap mode, the editor will place radially attached parts on exact angles for your convenience. In circle mode, you can stick radial parts anywhere you want.

Quote

It seems that the vast majority of people using this game are playing a version that barely resembles the original game, due to all the mods and add-ons being used...so when I watch someone showing how they build xyz craft or abc plane is it probably possible because of the mods and add-ons, and it's not mentioned in the video because they presume "everybody does it" (uses mods and add-ons)? 

I suspect not. There are very few mods that change the behavior of the craft editor. And you can do amazingly crazy stuff with the stock editor. So anything crazy you've seen in the editor is probably still pure stock. What you are seeing is probably the results of buttons and functions that you have not tried using yet.

Quote

in the case of this example would the antennas more easily break-off when going through an atmosphere at speed since they are no longer attached to the original green/black connection point? 

He didn't move them very far, so no they won't break off more easily. He rotated them, so their aerodynamic drag will change somewhat. Otherwise, they will operate normally.

Also, keep in mind that fairings, cargo bays, service modules, and service bays can shield parts inside them from aerodynamic forces. So even if you edit some part into some wacky attitude or position, you can still prevent any aerodynamic problems on that part with a fairing, etc.

 

Edited March 30, 2019 by bewing

[Aeroboi]

15 hours ago, Celthon said:

I've had the game less than two weeks, so mostly do not know what I'm doing...playing career mode, desktop PC, without mods or add-ons...as I build things I am careful to attach parts on the green/black indicators for "connection points"...but as I have been browsing through you-tube videos and guides I have noticed that many people are building things in which they move parts using the move and/or rotate tools, in some cases moving the parts what appears to me to be a significant distance from the original point it snapped onto.  My questions and/or confusions:

I know you play no mods... just to clarify. These people (including me) use...

In a nutshell: It gives you all the free editing room stock editor doesn't give to you

15 hours ago, Celthon said:

> Does the game's coding or mechanics or whatever you call the 'behind-the-scenes" part of the game not care where/how a part is attached to another part?

• Some parts are attached onto a node within a stack. A node (attachment node) is the green ball you see when trying to connect a piece to it. If it snaps it is snapped to that node. When something of 1.25m to 1.25m is attached to that node you have a sleak aerodynamic fuselage. Always try to connect 1.25 to 1.25 and use 1.25 to 2.5m adapters to make things look and function as sleak.
• Other parts however are "surface attachable" like some specific engines or science parts (among things). Usually these have little drag associated with them but are also best to attach to the green nodes to satisfy the best aerodynamic situation possible as that is often better.

15 hours ago, Celthon said:

> Are parts that have been 'edited' (rotated/moved from the original snap-to point) more prone to fall off, break or in some other way fail? 

I would consider myself very expert in addressing this point since I experimented with it quite often and have a lot to say for it. The bottom line that the rules in this are nonsensically arbitrary, so it's disgustingly pathetic how this works out exactly and I have no short explanation out of the sleeve to hand over to you.
First of all it's best to use "autostruts'
This is a function when you right click on a part followed by a context menu where it says autostrut with 3 options (heaviest, root and grandparent)
This option is only visible when enabling "advanced tweakables" in the main menu general settings (have to revert to main menu and have the "strut" part unlocked in the tech tree when playing career)

Autostrut rules in a nutshell: If you have a central stack (like a 2.5m rocket with several tanks, cockpit, and other modules within) then it is best to use only "grandparent part"
Especially when the vessel is long it is often useful to autostrut the far end (the engines) to root (assuming root is the cockpit above) to stiffen the rigidity over the full length.
If you have parallel tanks to the sides then it is best to use "Grandparent autostrut" only on the parallel part (fuel tank) that is directly attached to the central stack but the other fuel tanks attached to the parallel stacks are better attached to root or heaviest to weld the parallel rigidity to the core stack. Otherwise you grandparent the parallel tanks to the same fuel tanks on the parallel stack while it's better to strut it to the central stack which is stiffened through grandparent struts with which they're attached to.

Alternatively you can use the part strut but they have added weight and minor aerodynamic drag so try to avoid them. I usually only use them in odd situations where heaviest or root part are in off locations, or I use the strut part for looks as it may sometimes serve the aesthetic purposes.

Now, to address all the bits and pieces considering the above quote...

• Landing gear and rover wheels need to be straight. You can use number keys (1,2,3 and 4) to switch between Place, move, rotate and select root. You can use "3" (rotate) to put landing gear on a angle for better rolling stability. But this also means they will break faster when hitting terrain.
• The further any part (fuel tank or wing) is moved away from the parent part the less rigid it becomes. It may make it wiggle but it won't break off mostly. Under flight such parts are under aerodynamic stress and (rigid attachment will make connections brittle and break so don't use it) 
• Unfortunately with wings you want to add other sections to that wing but when you add more attachment points on the Width of a craft (by adding wing segments to other wing segments) the furthest attachment point becomes more flexing and brittle. Eventually there's a point where you autostrut them, fly your vessel under the best piloting skill and by the time you reach 400m/s they start to fall of. Does this mean you can't make massively large wings? Fortunately you can. What you want to do is place each individual wing part to the fuselage itself. That means you want your wing tip to be attached to the central fuel tank just as the first wing segment is which is directly attached to it. The culprit is that you have to move:tool each wing segment to the corresponding spot and that you have to individually move each part away from one another. With the editor extension mod posted above you should have the freedom to move parts anywhere even outside the space plane hangar lol
• Through this method of attaching wings I created the biggest rapier cargo SSTO there is (not the biggest but the most cargo capacity AFAIK) excuse me for undeserved boasting rights.
  
  If you want to magnify yourself into that design and how I made that SSTO then you can download it at my KerbalX. As you'll see each wing segment is placed seperately.
  https://kerbalx.com/Aeroboi/Hearts-Chevron-96-Cargo-Lifter-2375MC
   
• You also want to make sure wing segments barely touch one another as they might clip into one another at high speed and break. Best is to move them from one another until they barely touch one another.
• Attaching parts to specific other parts may prove better then attaching them to specific other parts. You can use the same SSTO again as I used the following trick for that design also.
  If you mouse point over the central main landing gear there are 2 "Extra Large landing gear" on that space plane. One of them is attached to the central fuel tank and the Engine block is attached to that main landing gear.
  You would have to use "absolute mode" (Press F) and use rotate (3) with (5-90° rotating increments, toggle using C) to rotate the engine block into linear relation to the fuselage.
  The apparent benefit of attaching super heavy stuff to landing gear is that landing gear parts are extremely rigid. (every landing gear with the heavy landing gear being the strongest)
  The further a part is from it's connection point the more wiggly it becomes.
  Landing gear doesn't wiggle and is shut stuck into position even if you drag it to the outside of your vessel. This is probably to accommodate rolling balance so wheels don't drift or shift out of balance because of silly wheel physics. Many people are aware that you can use hyperedit and drop a super heavy vessel using the "Heaviest landing gear" from 200meters high and hit the surface at 50m/s or more and survive. And well, that's the deal with these landing gear. They don't bend, wiggle, vibrate or even break. 
   
• So if you need something very heavy on one end (or both ends) of your vessel it's best to use the largest landing gear, drag it to the sides and remove lower/retract from the landing gear action group (unless it serves as landing gear as in my SSTO) and then attach the heavy module to it's surface and use rotation to snap it horizontal/vertical. The added benefit is that it is nearly impossible for it to break off. I tested this and it is the best method to have very heavy stuff hanging off from one side, the other benefit is that landing gears are very aerodynamic so they have no penalty to be used as such a rigid attachment surface and you can attach Kilotons to a Extra Large landing gear and it will serve it's purpose under what I consider ludicrous designs.
• Furthermore it is best to use the widest fuel tanks as possible. If the main stack is 2.5m try to stay at 2.5m and not shrink to 1.25m. If you have a 1.25m central stack with very much stuff hanging onto it and it has to endure aerodynamic stress then it is best to use a wider setup.
• If a part is rotated from another part (like in a ring station) the connection is just as rigid. But a rotation from one piece to another piece creates a spring effect while the snap off rigidity remains the same.
  So theoretically a rotated part under stress while it might be due to momentum (thrust) or impact should snap off sooner compared to not being rotated. AFAIK I have never snapped off a rotated part due to aerodynamics or impact so beyond theory you shouldn't worry. Just try not to attach something extremely heavy to a rotated part just to be safe, otherwise test it yourself and let us know

  16 hours ago, Celthon said:

  > If the parts have been moved (and to my thinking "misaligned") with the move and/or rotate tools, 1: are angles, 2:thrust lines, 3:lifting surfaces, etc., affected, causing a craft to behave in unexpected ways or to respond to control inputs differently than expected?

1: Angles:  For Vacuum spacecraft rotated misalignment usually doesn't matter. KSP calculates drag on the attachment setup. If 1.25m is attached to 1.25m it has no added drag. When you rotate them from one another they would increase drag because doing so creates a dent into a cylindrical shape and it increases the frontal cross section. On a jet engine SSTO this will be a problem as it may add to much drag to break the sound barrier.

2: Thrust lines: The same balance has to be met in terms of Thrust balance. You can use the "Center of Thrust" Purple icon to see how thrust moves through the CoM. If this thrust arrow moves below the CoM thrust will make the plane pitch up. So try to make the vessel so that the thrust arrow goes right through the yellow CoM marker. If you rotate engines to create something like a spaceshuttle replica you will have to pay special attention to this.

The SSTO I posted above is a good example whereby the Center of Thrust is a problem whereby I created a proper workaround by being able to toggle on/off engines modes so I can control pitch in the upper atmosphere and in space.

3: lifting surfaces

It has been mentioned before but you can rotate wings for desired lift effect called wing incidence. Imagine a airplane flying level at 0° pitch with 0° horizontal wings relative to the fuselage. What would the airplane do? It would sink...
Take any airliner on a picture album and see that most airplanes have their wing on a incline (That means the wing is rotated several ° above horizontal) In that scenario a airplane would stay level at 0° (at least at a certain speed: "cruising speed?")
This is so the wing has positive lift at operating speeds so that the fuselage is straight into the wind. If you don't put this incline (wing incidence) on the airplane the plane has to pitch to create the desired lift but the fuselage will also rise above the prograde reticle and suffer more drag whereby it enlarges the frontal cross section. AFAIK most SSTO professional users make use of wing incidence.

The only problem with wing incidence is that it creates a pitching moment based on the inclination of the wing. A inclined wing in front of the CoM will want to rise the nose. So what you do is rotate a incline on the front or rear stabilizers to re-balance this effect. Best is to design that the Center of Mass in Wet mode (fueled mass) is similar to the Dry mode (empty fueled) and you can use the RCSbuildAid mod to see dry/wet mass indicators using the CoM icon on the vessel.
It is best to balance this effect by rotating front/rear stabilizers to mitigate this effect. Otherwise the Elevon to correct that effect has to pitch and it will add drag. Keep playing with incline until the plane flies more or less level without control input or SAS and you will have little no no control surface drag.

Another point about lifting surfaces is that for the best "roll" effect elevons directly to the larboard/starboard sides in relation to the CoM across the vessel length will cause greater rolling torque. So if Elevons on the rear are set to roll (away from the CoM) the effect is lessened.
The closer the Center of Lift is to the Center of Thrust the less torque is required to roll, pitch or yaw the vessel. Sometimes however the front has more drag then the rear causing a plane to flip when achieving a certain airspeed if the CoL is to close to the CoM, so it is often better to place it somewhat behind the CoM unless you know what your doing and you want a very agile plane.
There are also wing attachment methods called dihedral and anhedral.

Dihedral is that the wings are rotated so that the tips point slightly upward. This creates a keeling/swing effect like on a marine ship and acts as a horizontal roll stabilizer whereby it's effect causes the plane to roll natively to 0° bank for level flight. The swing effect is that the Center of Lift will be above the Center of Mass making the mass of the vessel swing below the Center of Lift which is why it wants to natively level out when using this trick. The keeling effect creates native vertical stabilizing effect also.
Anhedral is the opposite whereby wings are rotated with the tips to the ground. Here the CoL is below the CoM. The benefit is very fast and immediate roll input. So for agility a small level of Anhedral wing design can be beneficial. It also creates the Keeling effect as with Dihedral.

17 hours ago, Celthon said:

> If none of this matters, what is the point of the green/black connection points...I was operating from the assumption it is where the parts have to be attached, to be attached 'correctly'...it's very possible I did not read something correctly or entirely in the beginning and have been operating with incomplete information.

To see where you could attach to? I know it seems straightforward but sometimes I create very tight adapters using cubic octagonal struts or attach a 1.875m engine plate to a 3.75m engine plate.
Then the nodes are packed together and I want to see what I'm attaching to what node as I sometimes miss click.
Usually I hold LEFT ALT (Right Shift on Unix)

when attaching to a node if a part is both node/surface attachable to make sure it attached to the node and not to the surface. Sometimes I have a cargo bay full with stuff with many nodes and I want a specific part attached at a specific node and it is best to see where the attachment point is.
Sometimes that attachment node is clipped inside a fuel tank. With the green/black node ball I can still see the node of the part while it is clipped. Otherwise I would have to drag the part out to see where I attached it to.

17 hours ago, Celthon said:

It seems that the vast majority of people using this game are playing a version that barely resembles the original game, due to all the mods and add-ons being used...so when I watch someone showing how they build xyz craft or abc plane is it probably possible because of the mods and add-ons, and it's not mentioned in the video because they presume "everybody does it" (uses mods and add-ons)? 

Sometimes they use 10 mods on a single plane or rocket. It would be quite cumbersome to list all mods used unless people want to specifically share it. Can you blame them? Ultimately it is your intention to play the game in thorough respect and will have to creativity to find out all the mods used in this game.
Personally I spend 2 days myself browsing the addon release page to learn about all the available mods out there. I suggest you do the same. Many of the threads are very informative about the mod usage and content.

Also, many people on here use many "gamedata" folders and have "Gamedata" backup folders. Some are for a specific modlist, other's are barely modded some have stock only (occasionally with visual mods)
So I have a stock KSP folder and one using many popular mods and 3 others also of which one has RSS installed. Remember you can copy/paste the entire KSP directory to another folder to have multiple KSP copies.

[Superfluous J]

3 hours ago, Aeroboi said:

I know you play no mods... just to clarify. These people (including me) use...

In a nutshell: It gives you all the free editing room stock editor doesn't give to you

I recently learned that you can move parts far away from their starting location by holding shift in the stock game. I have no idea when they added it, though it was the only original reason I installed EE back ... a way long time ago.

[bewing]

17 minutes ago, 5thHorseman said:

I recently learned that you can move parts far away from their starting location by holding shift in the stock game. I have no idea when they added it

Version 1.2.0 as I recall.

[Aeroboi]

25 minutes ago, 5thHorseman said:

I recently learned that you can move parts far away from their starting location by holding shift in the stock game. I have no idea when they added it, though it was the only original reason I installed EE back ... a way long time ago.

Hmm. I always used EER so I didn't know, but now I do, thanks

[Starhawk]

On 3/30/2019 at 2:51 PM, 5thHorseman said:

I recently learned that you can move parts far away from their starting location by holding shift in the stock game. I have no idea when they added it, though it was the only original reason I installed EE back ... a way long time ago.

This feature is so extraordinarily useful!

I only learned of this in version 1.5, myself.

Happy landings!