An exercise: DRAWING A PARISIAN FENCE

simon le bon

Dear Pilou,
thanks for this Jean Pierre Petit's link.

(When I was young, I was a wild and rebel, and bad student. I don't know why I want to understand everything like I do by now)

First a trick concerning a problem I have met: When I wanted to reconstruct the complex set of spirals by copy/rotate the basic section, that produced here and there some micro-cuts in the continuity of the lines.
I have used StrayLines to locate and label them

Repair,

>I want to understand better how the spiral works:
1)taking back my model
24 sided circle; 32 segmented face shape; each segment is 24 subdivided.
Each 360° turn of the shape describes completely one of the 32 face's segments.
24 single edges are necessary to achieve this single revolution.

Consequently, the entire spiral is made by 32 turns and no edge is used two times.
and we find effectively 32X24=768 edges

1)taking back Taff's model

Each 360° turn of the shape uses 60 edges (because of the 60 sided based circle).

The entire spiral needs 3 complete turns of the shape to be totally described.

3X60= 180 edges of the spiral.

Each edge of the basic section (90 edges) is used two times.

2X90= 180 edges of the spiral.

As I can understand the law of this:

the shape must make a number of entire 360° turns
the complet set of edges(included into the basic section) must be used a complete number of times.
the number of edges used in the number of complete turns must meet the number of edges constituting the basic section used to produce the spiral.

here: 60X3=180=90x2

to be verified!

simon

pilou

I believe that is the same problem for what Tig had made his True Tangents plug
Circles or helix ar not real circle, just polysegments aproximation , so in the 3D space there are some losses of precision after some turns

I have remarked that with my previous try above, I had must corrected by hand the join continuity!

ely862me

Hmm so much theory ..what i did was simple,make a spring,make a copy of it,take a spring and adjust it with ffd(remember to let the top and bottom points untouched) in order to make from it the inside part of the spiral, after this take the other one and flip it along in order to continue(descend on the outside) the first one,then play with ffd on it in order to make the exterior part of the spiral(remember to let the top and the bottom points untouched).Then i used lines to tube plugin. And that s kind of it!
Ah..and before working them with ffd i flattened(with ffd) the top and bottom spires of the springs to make a smooth transition from a spire to another.

infinite spiral a.skp

TaffGoch

Colors help identify the six separate (yet identical) loop components:

-Taff

simon le bon

@Ely,

Hi Ely, I like your way: searching for simple and quick processes your solutions are refreshing
SketchyFFD (Free Form Deformation) is a good deal for sure
[Plugin] SketchyFFD (Updated Aug 22, 2009) by CPhillips
SketchyFFD (Updated 9 Feb 2010) revisited by gbabcock
Making springs:
How to make spiral 02 by SketchUp
SketchUp: KitoRaupp_Pottery
(May be you can do a little more effort to explain in few several steps in your Skp rather than just show the result )

@Taff

Hi Taff (I have noticed you are from the early morning, and I'm waiting my own awakening to read your posts ) Thank you for your colored exemples. I guess the same treatment as you've done with your Geodesic Weave Ball should be also very great

Additionally, I would invite people to visit carefully your warehouse collections they are mines

and don't forget the "Help Group Discussion"

simon
re: what a great thread!!

TaffGoch

More torus segments produce results that better approximate the original images.
(Well, duh!)

Model available at 3D Warehouse

-Taff

TaffGoch

Simon,

I tried the chipped-paint texture, but it was too "busy," and was a visual distraction.

A simple texture looks good though, when rendered:

-Taff

simon le bon

Dear Taff,

Simple is the best; it is a "réussite" . I see it in 2D, spirit relaxing.
(But is it so simple? I mean about the discrete raw of light)

'Cause you seem also from late in the night, I wish U a good one.

simon

simon le bon

@simon le bon said:

As I can understand the law of this:

the shape must make a number of entire 360° turns

the complet set of edges(included into the basic section) must be used a complete number of times.

the number of edges used in the number of complete turns must meet the number of edges constituting the basic section used to produce the spiral.

and
4)the number of entire 360° turns of the shape must be the minimum one (sorry for bad explanation. I think it is the meaning of :"Least common multiple" )
(It doesn't make sens for the basic shape to go around more than the necessary number!)

@unknownuser said:

to be verified!!!!

I take back Taff's model to make a try to validate my thoughts

Not bad what do you think! slb

TaffGoch

Simon,

I didn't pursue the precise defining of the calculations, but I sensed the general concept of the relationships.

When I started on my second model, I roughly estimated a "longitude-to-latitude" ratio that should (might) produce a more-complex, tighter spiral with less slope, and six loops.

As an intellectual pursuit, yours is a good mental exercise. (Perhaps, if it were mid-winter, and I was snowed-in, then I would have time to wrestle with a precise definition.)

-Taff

simon le bon

@taffgoch said:

(Perhaps, if it were mid-winter, and I was snowed-in, then I would have time to wrestle with a precise definition.)

End of the exercise I suppose

simon!

simon le bon

by Cosycat

sim

TaffGoch

Cosycat's animated image is inspiring. I thought I'd give it a try, too:

-Taff

[ EDIT: I see that Cosycat's image is a creation of David Ope. ]
http://www.adaptcreative.co.uk/...
http://dvdp.tumblr.com/...

simon le bon

Hi Taff! impressive***

Can you say a little about your technique and the softs you're using? Please!
(and very nice links )

ely862me

@simon le bon said:

Hi Taff! impressive***

Can you say a little about your technique and the softs you're using? Please!

Looks like sketchup physics and a screen recorder(camstudio maybe).

Taff if u used Camstudio,please let me know ur settings ,i can t make it record that smoother.
Thanks!

Roger

Do not, I repeat "DO NOT" stare at these images for 15 minutes and then try to walk down the stairs!

TaffGoch

@unknownuser said:

Do not, I repeat "DO NOT" stare at these images for 15 minutes and then try to walk down the stairs!

Not to mention just walking across the room, without losing your lunch!

-Taff

TaffGoch

Simon & Elisei,

I tried using Camstudio, initially, but the results were poor. Camstudio is easy, but doesn't always provide quality results. It's great, for what it is intended, but there is a better option for a "looped" animation of limited frames -- GIF animation software. (This animation is composed of only 15 frames.)

I created the frames from SketchUp 2D exports, rotating the torus 2° each interval, producing 30° total rotation. (This matches the model component rotation of one spiral "tube" to the next.)

I kept the SketchUp viewpoint constant, and rotated the torus, to avoid any camera positioning problems. I could have established 15 camera locations, to produce 15 scenes, but the way I did it was quicker. (Creating 15 camera/scene postions, however, does have the advantage that they can be saved in the model file, for subsequent use.)

I assembled the 15 frames into a GIF animation, using JASC "Animation Shop," which I bought (cheap) over ten years ago. It's my understanding that COREL bought-out JASC. The older "Animation Shop" (vs 3) can be downloaded from several online sites, or you can use one of the MANY other freeware GIF animators, available online.

[NOTE: I used the same technique to create my avatar.]

-Taff

Simon B

Well, it works for me.

More inspiration here

Arc

Play with tours and component stringer.