Geodesic Dome Truss by TaffGoch - cloning to sphere?

TaffGoch

Tonttu,

I don't think that Frenchy's suggestion will work (unless Chris Fulmer modified his plugin, to autorotate & scale-to-fit.)

That particular truss will only produce a sphere if 20 copies are used, rotated around the correct axes, by the correct angles. I did exactly that, in less than a minute:

The angles are not troublesome (72°), but the axis-of-rotation might cause a SketchUp novice some problems.

Do you already know how to rotate entities around any axis of choice?

SketchUp permits you to select the endpoints of the rotate axis-line.( SketchUp Sage - Rotate Tool )

Using the Sketchup "any axis" technique, choose the origin as one endpoint, and a corner of the truss as the other end. A 72° rotation will butt the edges of the two trusses against each other. (Beforehand, you should make that truss a group or component, to make selection easier.)

-Taff

Tonttu

Many thanks for the mini-tutorial! Yes, I'm a complete novice, but I'm familiar with action centers/axes especially from working with Modo, so I think I can get the hang of those any axis rotations.

pilou

@TaffGoch : you rocks
I have seen your origin or rotation in the first file linked
I had the intuition that your part of truss can make a sphere but want to find another method

I believe that the Chris Fullmer plug can make the trick (inside a geodesic Sphere)but you must adjust the module component position after running the plug
if you have made the module without attention
It's the internal axe of the module component who makes the différence!
(so edit the module component

You have also somme plugins like Mirror by Tig or Align by Didier Bur who can help for make somme copies in the space
when they are not align to the axes

Tonttu

How do I find the origin (0,0,0 ?) for the rotation? The truss was already a component, so I copied and pasted it in place.

gilles

zoom out the model you will find a guide point it's the center of the geode

Tonttu

Yeah I tried that center point already (at the bottom), but using it as the first point and a corner as the endpoint only gave me a "six pointed star", ie. it rotated around the center point.

Tonttu

Ok I chose the points in reverse order and it seemed to do a better job, but it's a long way from a curved surface! This is basically a radial array, which will just produce a bumpy result.

failed attempt

TaffGoch

Tonttu,

If you have guides visible (View > Guides), you should see the central guidepoint.

Use
(1) that guidepoint and
(2) one of the primary corners of the truss, as
(3) the endpoints of the rotation axis,
(4) rotate by 72°

I have revised the model to show, more-clearly, the rotation axes. (The guidepoint was already there. I added only the guidelines.)

-Taff

TaffGoch

Tonttu,

I see now what you're doing wrong!

You are not using the "drag" technique, to specify the endpoints of the rotation axis.

You are, wrongly, rotating in some other plane; perhaps, the "blue" plane.

-Taff

Tonttu

Ok I changed to women's clothing and I'm trying to rotate now.. Kidding! Thanks man, you've opened a new psychedelic world of rotation for me! Everything is locking into place now.

TaffGoch

Tonttu,

You can understand why I always teach that rotation technique first, to a new user.

I couldn't model without it!

Tonttu

Yes I noticed the slight misalignments, but I think the accuracy is enough for my purposes.

TaffGoch

My apologies,

This is one of my oldest SketchUp models, which I built while learning SketchUp. As such, there are slight inaccuracies, regarding alignment of the groups and guidepoints. So, your rotation alignment problems were caused by my inaccuracies in placing the central guidepoints.

I have updated the model, to properly-align. I have also included an icosahedron, to depict and help visualize the rotation symmetries. I rotated the truss component, to the more-prevalent orientation, of a primary vertex pointing upwards (rather than a face.)

Update in 3D Warehouse: Geodesic Dome Truss

-Taff

brookefox

@unknownuser said:

@TaffGoch : you rocks
I believe that the Chris Fullmer plug can make the trick (inside a geodesic Sphere)but you must adjust the module component position after running the plug
if you have made the module without attention
It's the internal axe of the module component who makes the différence!
(so edit the module component

It would seem that you are correct, professor, and I had some success at relocating the component axes for the purpose of using the component on to face plugin to exactly place the 20 pieces, but not nearly good enough.

Did you ever figure it? geodesic-compo to face-1.JPG geodesic-compo to face-2.JPG geodesic-compo to face-3.JPG

brookefox

'Component onto face' doesn't know the rotation that is desired and so cannot necessarily properly rotate it but still it can be used and the results tweaked because in this case there are only 2 rotations.

pic shows components as placed; 10 'wrong', 10 'right.' All endpoints should be at intersections.

faces into components-2.JPG