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[1.11.x] RCS Build Aid v1.0.6


m4v

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On 10/18/2016 at 6:01 PM, Alshain said:

@m4v I had a similar issue with my buttons and @DMagic was able to provide a work around.  Not sure if it is the same issue or not, but the visibleScenes parameter appears to be bugged so you just have to destroy your button every time a scene changes to where it shouldn't be and then recreate it again later.

 

What's interesting is that I experienced the RCS build aid button appear on the flight scene as soon as I added Contract Configurator.  It's not the "broke because of Blizzy Toolbar detection code" but I find it interesting that a mix of mods can make it appear, disappear.  Here is my KSP.log after adding Contract Configurator if there's anything of value: https://drive.google.com/open?id=0BxCPohKyyq63X0NDM2NFajhoRWM

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1 hour ago, Fwiffo said:

Could someone tell me what drycom_MJPropellant in the settings file means / meant?

"drycom_<resource>" is just a variable for remembering if a given resource should/shouldn't accounted for the DCoM calculation. If a mod adds resources then RCSBA saves a setting for it.

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Thanks.

BTW different issue.  I didn't do any troubleshooting, but thought you might like to know I had to remove RCSBuildAidToolbar.dll to get my RCS Build Aid window to show up.  Using blizzy toolbar v1.7.13.

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  • 2 weeks later...

I have a question that I can't find the answer to, no matter how much time I've spent looking. WHAT IS THE RED ARROW POINTING PERPENDICULAR TO THE CIRCULAR RED ARROW? I get all the other arrows, but why is the orthogonal arrow there? What does it indicate? If I've placed unbalanced thrusters and I am checking translation balance against a starboard burn that will rotate the vessel to port, why is there an orthogonal red arrow pointing out of the CoM, what does it tell me?? *I am not referring to the circular rotation arrow*

 

Thanks!! :)

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10 minutes ago, Variety_Pack said:

I have a question that I can't find the answer to, no matter how much time I've spent looking. WHAT IS THE RED ARROW POINTING PERPENDICULAR TO THE CIRCULAR RED ARROW? I get all the other arrows, but why is the orthogonal arrow there? What does it indicate? If I've placed unbalanced thrusters and I am checking translation balance against a starboard burn that will rotate the vessel to port, why is there an orthogonal red arrow pointing out of the CoM, what does it tell me?? *I am not referring to the circular rotation arrow*

 

Thanks!! :)

From the first post in this topic:

" Cyan arrows represents thruster forces, the green arrow represents the translation motion (or thrust). The red arrow represents the torque force in your vessel, if you have a red arrow then your ship will rotate when trying to translate in docking mode. So all you have to do is place your RCS thrusters in a way that eliminates this force. The red circular arrow is an indication of how fast the vessel will rotate. The red CoM marker is the dry center of mass (DCoM) which represents the center of mass of your vessel when it doesn't have any fuel (in the picture, without liquid fuel, oxidizer or mono-propellant, but is configurable)."

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The other way to look at it is more complicated. Anything physics involving an orthogonal direction, you have a normal force at play. I hope this links correctly, Although it's not ideal, it was the best I could find on short notice.

As mentioned, whenever a rotation is being imparted, the resulting torque is felt as a normal vector. This to me is one of those counterintuitive to normal life but normal in physics sorts of thing. (No pun intended on use of "normal", here! D'oh!)

I've never been great at physics descriptions though :( 

Edited by komodo
D'OH
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27 minutes ago, komodo said:

The other way to look at it is more complicated. Anything physics involving an orthogonal direction, you have a normal force at play. I hope this links correctly, Although it's not ideal, it was the best I could find on short notice.

As mentioned, whenever a rotation is being imparted, the resulting torque is felt as a normal vector. This to me is one of those counterintuitive to normal life but normal in physics sorts of thing. (No pun intended on use of "normal", here! D'oh!)

I've never been great at physics descriptions though :( 

Vector math is simpler than trying to do math that works with rotating planes. The normal convention for the direction of the torque vector is to use right hand rule (fingers of a right hand points in the direction of a motion and thumb then shows the direction of the vector), so torque can be calculated as the cross product of two vectors: radius x force.

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  • 3 weeks later...

I'm probably being dense. I get the red circular arrow representing direction of rotation and that the larger it is, the more torque is exerted. You've probably explained this in your comment, but there is a red arrow that points out of the center of the red circle. So if I have placed one linear RCS thruster on the top of the nose of a vehicle, attempting translation would result in negative G for the pilot and poisitive G for the tail as described by the huge red circle-arrow, and there is a red arrow pointing out of the center towards the port side. What force is being imparted to port?

 

This will be certain we are talking about the same arrow.

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2 hours ago, Variety_Pack said:

I'm probably being dense. I get the red circular arrow representing direction of rotation and that the larger it is, the more torque is exerted. You've probably explained this in your comment, but there is a red arrow that points out of the center of the red circle. So if I have placed one linear RCS thruster on the top of the nose of a vehicle, attempting translation would result in negative G for the pilot and poisitive G for the tail as described by the huge red circle-arrow, and there is a red arrow pointing out of the center towards the port side. What force is being imparted to port?

 

This will be certain we are talking about the same arrow.

The red circular arrow represents the angular acceleration, the straight red arrow is the torque vector. Torque is always represented as a vector that points along the rotation axis. In practice you don't need to give much attention to that vector though.

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Okay, so what is a torque vector? I've Googled to cure my ignorance but all the words just washed through my brain like so many neutrinos. Is it something like gyroscopic precession? I only generally understand that concept insofar as it relates to helicopter blades and bicycle wheels, and I wouldn't think my ships gyrate so fast as to make that even remotely relevant.

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2 minutes ago, Variety_Pack said:

Okay, so what is a torque vector? I've Googled to cure my ignorance but all the words just washed through my brain like so many neutrinos. Is it something like gyroscopic precession? I only generally understand that concept insofar as it relates to helicopter blades and bicycle wheels, and I wouldn't think my ships gyrate so fast as to make that even remotely relevant.

Take you right hand, point your thumb, and curl your fingers.  If your thumb is pointing in the direction of the torque vector, the object will rotationally accelerate in the direction your fingers are curling.

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4 minutes ago, Variety_Pack said:

Okay, so what is a torque vector? I've Googled to cure my ignorance but all the words just washed through my brain like so many neutrinos. Is it something like gyroscopic precession? I only generally understand that concept insofar as it relates to helicopter blades and bicycle wheels, and I wouldn't think my ships gyrate so fast as to make that even remotely relevant.

In the easiest terms I can put it, if you spin a top, the torque vector is the middle pole that the top is spinning on.

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19 minutes ago, Variety_Pack said:

Oh I didn't realize it was the "pivot point" of the rotation. I was assuming vector meant it went that direction, as in vectors during a dogfight. Thanks, I get it now!

It confused me that it only points out to one side.

Can't guarantee that it works correctly in the addon, but it *should* point out the other side if you reverse the direction of the display. (That is, if pointing in one direction for "left", it should invert for "right".)

As for why... the right hand "rule" was a couple posts up. I wouldn't be able to sit and derive it off the top of my head though, these days.

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10 hours ago, Variety_Pack said:

Oh I didn't realize it was the "pivot point" of the rotation. I was assuming vector meant it went that direction, as in vectors during a dogfight. Thanks, I get it now!

It confused me that it only points out to one side.

It's a hangover from before MV4 had the code to draw the circular torque arrow. It can still be useful occasionally when, for whatever reason, the circular arrow is hard to interpret or doesn't draw.

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14 hours ago, Variety_Pack said:

Okay, so what is a torque vector? I've Googled to cure my ignorance but all the words just washed through my brain like so many neutrinos. Is it something like gyroscopic precession? I only generally understand that concept insofar as it relates to helicopter blades and bicycle wheels, and I wouldn't think my ships gyrate so fast as to make that even remotely relevant.

Not exactly easy to understand if you have no background knowlage in math and physic, but wikipedia about couple of forces and about torque is good start.

Basicaly, if you put in consideration rotation only on one axis (either of putch,yaw or roll), you can sum up all of forces that act on your craft to only one force vector on some distance from COM. One for each side of distance from COM, actualy. You need to sum up all other forces into other force vector that act on oposite side from COM. So, you can simplify all math to only two forces and two distances from COM. Like on this picture:

Fig-8-2-a-1.JPG

That is best one I could find in this quick google search that match topic.

Try to calculate torque from only one force at time.
Let say root of vector P is COM of our craft. Vector P is calculated as cross product of distance between COM and root of F1 and F1 vetor itself. If you use right hand rule as adviced, you need to put facepalm to point from COM to root of F1 vetor, or if applied to your KSP craft towards front. Other fingeres are curled towards F1 point. Thumb of right hand point to direction of vector P. That is your red arrow from question.

Now, when you do the same thing for F2 you will also get vector that points UP. That is summed up with vector from F1, meaning, your craft will wildly rotate. That is good if you want to rotate your craft.

However, if you want to translate craft on a side, instead of rotate, you want to F2 to point in oposite direction, paralel to F1 vector. When you do cross product of distance from COM and new F2 vector you will get some other momentum vector, let's call it P2 that will point down. You sum up P1 vector from F1 cross product and P2 vector from cross product of F2. Resulting vector is actualy that red arrow you asked what it is.

Idealy, for translation, you want it to be zero. However, if it is not, you point thumb of right hand to direction of resulting P vector and curled fingers gives you way of rotation, like it is shown on above picture.

So, instead of doing all those calculations by hand each time you design your craft, you can use this awesome mod to just show you result of those scary math.

Now, when you know all this trickery magic, you will notice that if you have craft with long tail, you can use smaller sized RCS near tail that also have less weight that can easy counterpart larger and heavier RCS in front that is much closer to COM. How you will use that new knowlage on your crafts is up to you.

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3 hours ago, Variety_Pack said:

Force times Radius is Torque

Nope. You have been told wrong in school. It is not Force times Radius.

It is Radius times Force.

It does not matter in scalar products, but order of parameters matter in equation of vector cross product.
You can get totaly oposite direction if you apply right hand rule on cross product.

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Hey everyone. I can't find RCSBA on my CKAN list for 1.2, and I really miss it. I don't see anyone else having the same issue though, and earlier in this forum, it said that RCSBA got updated for CKAN by the CKAN folks. Anyway, I'm sorry if this has been discussed elsewhere--I've searched all over and can't find any info.

Is it available in CKAN and I'm just missing something?

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49 minutes ago, MitchS said:

Hey everyone. I can't find RCSBA on my CKAN list for 1.2, and I really miss it. I don't see anyone else having the same issue though, and earlier in this forum, it said that RCSBA got updated for CKAN by the CKAN folks. Anyway, I'm sorry if this has been discussed elsewhere--I've searched all over and can't find any info.

Is it available in CKAN and I'm just missing something?

Should be. But this is better to ask in CKAN thread. Is it available already or not depends on values in .version file for both, AVC and CKAN bot.
If there is written that max supported KSP version is 1.2.1, for example than it would not show up on CKAN. Metadata for those have to be manualy owerriden by CKAN staff members. That can be a while until everything is settled down. I'm still on KSP 1.2.1., so I can't check out for KSP 1.2.2.

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8 hours ago, slackitude said:

I'm trying this mod out for the first time, I'm on KSP 1.2.2. I see all the colored arrows, etc, but the window that should have options in it is empty. Just the title bar is there. Am I doing it wrong? Or maybe a bug? 

if you can put a screenshot we might have a better idea of what is going on.

edit: maybe the window is minimized, click the small button in the right top corner of the window, is a little square.

Edited by m4v
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