Shaping a cylinder - interesting technique

thomthom

That method with selecting a line along the length of a segmented tube, using the protractor to bend it... what on earth is going on here? I don't understand. I see it working, but I don't understand. Though, somewhat unpredictable, it's very cool.

pilou

@unknownuser said:

what on earth is going on here? I don't understand. I see it working, but I don't understand

Maybe like this?
As the spiral line is inside each little "squares" (hidden geometry) and these are "unbreakable" all must follow!

jeff hammond

pilou, thomas is talking about a separate techinique

watch this and please tell me what is happening.
http://homepage.mac.com/jeffhammond/.Public/scf/Qtool.mov

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kwistenbiebel

Could this technique be made into a ruby?
Following what I see in the youtube (using the auxiliary spiral), this could be done, right?

A ruby that would model the spiral for you and make the scaling behave as described in this thread would be wonderful.

thomthom

@kwistenbiebel said:

Could this technique be made into a ruby?
Following what I see in the youtube (using the auxiliary spiral), this could be done, right?

A ruby that would model the spiral for you and make the scaling behave as described in this thread would be wonderful.

Harnessing it into something more controllable... hmmm..

pilou

@unknownuser said:

watch this and please tell me what is happening.

Maybe this little image can explicit that
No magic inside, it's totally normal! (click image if scrollbars)

It's like escarpolette (seesaw) Ground don't move!

Ecuadorian

Just stick to the standard 640x480 size and you'll get no scrollbars.

xrok1

pilou, it works with no bottom as well! you may have something with the triangle thought but it would be the triangle nearest to the selected edges that would be effecting the shape not the ones on the opposite flat side.

pilou

Yep but these are fixed too!

thomthom

But how come it only grows?

Gaieus

@unknownuser said:

Hm... Fragonard...
Good taste, Pilou (I think I'd better go back to teach art history )

pilou

@unknownuser said:

Just stick to the standard 640x480 size and you'll get no scrollbars.

But i was under with 547*358

pilou

@unknownuser said:

But how come it only grows?

Only grow? No grow and ungrow!

Because face arcs' side are fixed on their "bases" and make "pivot"
All up mesh is free to deform!

See first second of that (second 10 to second 15)
[attachment=0:15wm2z0r]cards.jpg[/attachment:15wm2z0r]

jeff hammond

here's a variation which keeps the hidden line straight during the rotation and allows the base to move..

variation.skp

explode the arc then weld the segements together prior to building the base..

jeff hammond

@ecuadorian said:

Just stick to the standard 640x480 size and you'll get no scrollbars.

just click on the picture and you won't have to scroll.

BTM

Ah! My post is gone.

...Now a shorter rewrite...

I think what's happening, and maybe what Pilou's trying to say, is that the ends of the arcs are stationary, and the arc has to stay and arc, and therefore the area selected can't rotate, because it can't deform the arc. So you're trying to rotate something that can't be rotated. I don't know exactly why it expands the arc, maybe it's trying too hard to have it rotate, and the only place for it to move is up.

Jim57

I'm not sure what I'm doing wrong (or not doing), but neither of these works for me. What exactly are you grabbing with the Rotate tool? One of the straight hidden geometries that goes from end to end? Over what length? When I download the example above I can only twist a small bit of surface.

On the full cylinder, same thing— I get wild deformations coming out of every which way when I Scale the spiral, but not the smooth shapings in the video.

TIA,

JIm

simon le bon

Goodmorning Sketchy Fellows,

I come back to the initial subject of this thread for I have to say one: "what a fantastic and fun way to potter a shape !!", and secondly to ask a question I can't answer by myself.

Why only a 15° disc rotation allows copy of ring angled edges to fit with the source, whatever the height is?

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