Multiway symmetry

[Hotel26]

(I thought I used to know a way to do this involving Alt-Right-click or Control-Right-Click...  but it's very elusive.)

I've placed 4 tanks around the big one in 4-way symmetry.  Now I want two solar panels on two of those tanks in 2-way symmetry.  And then I'll put e.g. 2 fuel cells, in 2-way symmetry on the other two tanks.

I've resorted to 1-way symmetry to place each solar panel separately but then the symmetry isn't perfect.

This is just an example.  I'm looking for a general technique.

I'm pretty sure this is possible in stock.  (I'm not too interested in mods for this.)  Anybody know the trick?

Edited July 11, 2018 by Hotel26

[Nightguard]

so far, i dont think you can put x2 symmetry if the part youre putting the part on is on 4x. just put 2 pairs of 2x symmetry and use the grid, that way, you can use 2x symmetry on the panels.

[4x4cheesecake]

4 minutes ago, Nightguard said:

so far, i dont think you can put x2 symmetry if the part youre putting the part on is on 4x. just put 2 pairs of 2x symmetry and use the grid, that way, you can use 2x symmetry on the panels.

That's the stock way and how I would do it as well.

1 hour ago, Hotel26 said:

(I thought I used to know a way to do this involving Alt-Right-click or Control-Right-Click...  but it's very elusive.)

Sounds a bit like the strip symmetry feature of 'Editor Extensions Redux' (alt + shift + left click).

[Hotel26]

What my vague recollection might have been about was how to put 2-way symmetry (2 parts) onto another part and then place that part in 4-way symmetry (including its 2 subparts).  That one is an order-of-execution problem.

OK, so maybe you can't do it.  In which case, "the stock way" (thank you!) would work but if one got really fussy about the symmetry of the 2 and 2 (small tanks in my screenshot), then one could place 4x Octa struts in 4-way symmetry, and then place the prepared tank-and-item individually 4 times (1-way) but rely on NightGuard's "grid" (snap to location) suggestion to get perfect symmetry -- with good use of the Mk-1 eyeball...?

Thanks (so far), guys.

[Gargamel]

Make your pairs of tanks in pairs, but use guides.  I'm exhausted, can't keep my eyes open, but I'll try to explain how I used to do something similar for 8x asparagus stages, that dropped off in pairs.

1)  Slap your 4x tanks on the core tank.  Get them aligned just like you want.   Now grab something like the non extending antenna, and place 4x of them, aligning them exactly to a point on the 4x tanks.  Place them so you can exactly line up the tanks later vertically. 

2) Remove the 4x tanks, add 2x tanks, lined up exactly as you just did, using the antenna's as guides.

3) Add anything you want on all 4x tanks to the tanks now.  Doing this now will guarantee symmetry for these items. 

4) Alt-click the 2x tanks, and place these new tanks in the correct spot 90' from the first two.  Again, using the guides for alignment.  With a little practice, you can get spot on with the vertical symmetry of the pairs of tanks.

5) Now you have 2 pairs of tanks, in 2x symmetry each, top aligned vertically across the ship.  As long as 2x symmetry is selected, any part you now add to one tank, will only be added it it's twin on the other side. 

Oh! And 6) Remove the alignment antennas. 

 

EDIT: In this case, alt clicking is a good habit to get into.   If you are building an asparagus booster, You should make one pair first, and then adjust all your staging as necessary.   Chutes (for stage recovery), sepatrons, main engines, launch clamps, etc, should be adjusted correctly now.  And then when alt-click for the next pair, all the staging setups will carry over to the next set.  The set's of staging icons will be nicely grouped together to make it easy to separate them into unique stages.  

 

Edited July 11, 2018 by Gargamel

[4x4cheesecake]

@Gargamel That's a nice idea how to do it, but if you do this just to drop of pairs in aspargus stages, there is an (in my opinion) easier way:
You can split groups of parts in the staging bar. So you can place the radial decouplers in 8x symmetry and drop them in pairs anyway.

Create a new stage, expand the decoupler symbol in the staging bar, which will show you the 8 green marked decouplers. Then you can 'shift + left click' (in the staging bar) to unselect parts of this group until just 2 of them remains , which can be placed via drag&drop in your new stage.

Edited July 11, 2018 by 4x4cheesecake

[GuyWithGlasses]

5 hours ago, 4x4cheesecake said:

@Gargamel That's a nice idea how to do it, but if you do this just to drop of pairs in aspargus stages, there is an (in my opinion) easier way:
You can split groups of parts in the staging bar. So you can place the radial decouplers in 8x symmetry and drop them in pairs anyway.

Create a new stage, expand the decoupler symbol in the staging bar, which will show you the 8 green marked decouplers. Then you can 'shift + left click' (in the staging bar) to unselect parts of this group until just 2 of them remains , which can be placed via drag&drop in your new stage.

But AFAIK,, if you do it that way, (in the vab) yo cant change the crossfeed priority of the tanks, so itsnt asparagous staging (but you can do It before the Launch).

[4x4cheesecake]

1 minute ago, GuyWithGlasses said:

But AFAIK,, if you do it that way, (in the vab) yo cant change the crossfeed priority of the tanks, so itsnt asparagous staging (but you can do It before the Launch).

Well, that's right and something I didn't think of because I'm using fuel lines instead of fuel flow priorities. Once, I tried an aspargus design with fuel crossfeed through the decouplers, but there is something that bugs me about this option (or maybe I did it just wrong): The engies don't shutdown as soon as the tanks above them are empty. If you use fuel lines instead, the engines stop burning so you will get a visual signal for your staging without looking at the fuel level of the tanks. (Obviously, this doesn't apply to really huge aspargus design with 20+ engines)

[GuyWithGlasses]

1 hour ago, 4x4cheesecake said:

Well, that's right and something I didn't think of because I'm using fuel lines instead of fuel flow priorities. Once, I tried an aspargus design with fuel crossfeed through the decouplers, but there is something that bugs me about this option (or maybe I did it just wrong): The engies don't shutdown as soon as the tanks above them are empty. If you use fuel lines instead, the engines stop burning so you will get a visual signal for your staging without looking at the fuel level of the tanks. (Obviously, this doesn't apply to really huge aspargus design with 20+ engines)

Yeah, thats true, even mechjeb doesnt recognice that the tanks are empty and doesnt stage it. I've always thought its cause the fuel flow is bidirectional with the decopulers and unidirectional in fuel lines.

BTW, lately I prefer configure the rocket with fuel flow priorities cause its a bit more flexible ( for ex. because the TWR of the staged rocket goes much lower than the TWRs of the not-staged rocket).

 

 

[Gargamel]

9 hours ago, 4x4cheesecake said:

@Gargamel That's a nice idea how to do it, but if you do this just to drop of pairs in aspargus stages, there is an (in my opinion) easier way:
You can split groups of parts in the staging bar. So you can place the radial decouplers in 8x symmetry and drop them in pairs anyway.

Create a new stage, expand the decoupler symbol in the staging bar, which will show you the 8 green marked decouplers. Then you can 'shift + left click' (in the staging bar) to unselect parts of this group until just 2 of them remains , which can be placed via drag&drop in your new stage.

I've found the problem to be doing it this way, is that it is difficult to identify which decouplers and such go to which stage.    Mousing over 1 of 8 different icons, then trying to safely drag it to another stage, works, but is cumbersome.   But if you make a clone of a pair instead, the staging icons will appear in groups, but in the same stage. 

8x symmetry will give you 1 group of 8 decouplers, and 2 groups of 8 sepatrons in one staging block.   

2x cloned will give you, in order:

2 decouplers

2 sepatrons                > Original stage

2 sepatrons

2 decouplers

2 sepatrons                 > Cloned stage

2 sepatrons

 

The bottom 3 groups are from one stage and the top 3 are from the first.   So if you build your 'root' booster stage first, and clone around the ship from there, this time using they pointy antenna as a guide point for the corner of the decoupler, the staging will just be drag the bottom three pairs down into a new stage.  And then you clone that latest stage again, and the staging groups will line right up for you.      And now, since all the tanks are in 2x symmetry, you can easily drag and drop the requisite fuel lines as desired.

I have never bothered to figured out that new fangled fuel flow stuff, yet.   Someday. 

------ Another option to the OP...

Use the antenna guide trick for the parts you want to add.     If you require PERFECT symmetry for the tanks for some reason, then make one tank with a set of solar panels where you want, drop a guide point for the panels, and then remove the panels, and add the fuel burny thingies cells, and add a guide point.   4x symmetry the tanks, and then add the panels and cells as desired.    Unless you really need perfect vertical alignment for the side tanks, I don't like this way, but it's an option.