# Need Help with 3d Alignment

Hello

I’ve been using Rhino to design Stained Glass art, it’s very useful as the 2d drawings can represent the glass panels very well

Came across a complication now that I am making 3d pieces, I don’t know how to align the pieces in 3d plane.

I figured out a trick that has been “good enough” but it’s very time consuming and doesn’t work for more complex structures.

In the photos I raise the pentagons so they join at the corresponding angle, I end up drawing a reference line where I want them to join and then align them with 3d rotation as close to the line while using 2 Viewports.

They never fit perfect (by millimeters, which add up)

I kindly ask for help regarding 3d alignment of faces, I have heard of constraints (which I don’t know how to use) but maybe there is a more simple solution?

Thank you for your time, stay creative!

I tried finding that intersection and snapping to it…

and then after that measuring where a rotated polygon falls…

if you ignore my file tolerances’ deviation the answer is 63.435 rotation needed

Steps below:
Finding_Don-Decahedro.3dm (221.6 KB)

I think this approach should be pretty scalable to most prismatic forms.

G

Hi, thanks so much for the quick response.

Where did you learn to use those side menus?

I found them and I see there is a wide variety, now I want to learn to use them all hehe.

I’ll research videos, PDF & Forums.

Have a wonderful day/night

I’ve learned most of it here. There’s a lot more that’s what’s on the menus. The off-menu commands lists is extensive too, with over 1000 long I think.

Have fun!

2 Likes

Hi @joshua_mora
If you do a lot of these, it might be worth looking into Grasshopper/Kangaroo for this.
magnet snap assemble.gh (18.7 KB)

HTH, Jakob

6 Likes

don t want to be the lazy party pooper…
but there is a nice free plug-in to create polyhedra:

## math

see dihedral angle (angle between two planes / planar faces / along edge)
here

### calculation

you can use
`_rotate3d`
and enter the angle as commandline-calculation
`acos(-1/5*sqrt(5))*180/Pi`

## construction

my approach would be to use arcs to construct intersection points to get the angle.

to draw the first initial (green) arc you can
either draw circle around curve ( which would require the blue construciton lines)
or use a c-plane and project Osnap (faster)

_mirror (cyan)

_intersect

_rotate3d

2 Likes

Yeah, much cleaner!

1 Like

Alternatively, for a Dodecahedron you could simplify and enter below as angle:

`atan(2)*180/pi`

i’m curious if constraints can be used in the WIP instead ?

_
c.

This seems exactly like what I was looking for.

I say seems because going trough setting up everything I learned many things are not compatible with Rhino 5, including Kangaroo2

I can’t install Rhino 6 on my current pc because it is 32bit but I will try to fix my broken 64bit one.

I’ll comment how it goes If I make it work and post my results with the script.

Thank you so much, and for the video too!
To all others that answered too, much appreciated.

Happy creations!

This sure seems interesting.

I don’t have much knowledge in math but I’ll research a bit to understand more fully, it gives insight on how to use the tools available in many different ways.

I will test this if my other pc doesn’t work, will check it out ven if it does, great practice

Thanks!

Hello, sorry for asking so late (I finally have 64bit system again)

I incorporated the grasshopper to Rhino window and a red block appears in the middle.
But when I draw some polygons they dont appear red as yours.

Ive tried searching and other methods but havent managed.
If you could help me Id be very grateful.
Good Day"

Hi @joshua_mora
I’m currently away on holiday and won’t be back in the office for another 2 weeks, but basically you’ll need to link your new shapes to Grasshopper using the geometry input. I don’t remember if the shapes in the GH-file are made in GH or embedded geometry, but hopefully someone not 1600 km’s away from his/her computer can help you in the meantime.
Regards, Jakob

I understand, I will mess around trying to figure out how to do it. I’ll research about the things you suggested.
Thank you so much, you’ve helped me a lot.
I’m looking forward to learning grasshopper to interact with the community more.

I think now I have to venture into learning how to use grasshopper more, so I’ll start new questions another time in a different thread.