How to make a Zoetrope ?

Hi everyone !

I'm quite a begeinner with Grasshopper. I would like to make a 3D printed zoetrope like this from 8 body shapes:

First things first I have to array my 8 shapes along a circle like this, i tried but i can't do it:

Then I have to join them with a mesh.

Can someone explain me how to do it ? The .gh file is the best I can do. I think the best way is to set each shape to each 8 points on the divided circle.

Many thanks !!!

Attachments:

zoetrope.3dm, 360 KB
Zoetrope.gh, 5 KB

Replies to This Discussion

Permalink Reply by Joseph Oster on November 7, 2017 at 9:00am

For several reasons, I wasn't quite satisfied with yesterday's results.

'Sweep1' breaks easily.
the need for 'ReB (Rebuild Curve)' loses some of the details of the body shape curves.
The sweep surface and resulting isocurves are twisted because the start/end points for each body curve are not aligned.

I tried a few different things and came up with this, which looks better but might still be improved with more careful adjustment of parameters.

First, I added an array of eight sliders to adjust the 'Seam' for each body curve so the start/end point for all of them is at the tip of the person's nose. 'Sweep1' still failed at first but a very slight adjustment of just one slider made it work!

Second, I used these aligned start points to create a new rail curve, instead of the circle. I also tried moving the circle up but that didn't seem to work as well as the interpolated curve that actually touches each station curve.

Third, I increased the rebuild count to 400 so the curves are a closer match to the originals, gaining more detail. Even so, I used the original curves for the eight 'Boundary' surfaces because they have fine details that are lost in the rebuilt curves.

It's hard to explain all the trade-offs because 'Sweep1' is so delicate and breaks for mysterious reasons. It can return a "Closed Brep" instead of a surface, which causes 'Iso' to fail, of course. Slight adjustments will cause it to work as expected again. It's not easy to make this look "smooth"...

Attachments:

Zoetrope_2017Nov7a.gh, 35 KB

Permalink Reply by Joseph Oster on November 7, 2017 at 9:11am

P.S. One more tiny detail - the 'Boundary' surfaces can include the holes that are part of three of the eight body shapes by making this very small change:

Attachments:

Zoetrope_2017Nov7b.gh, 35 KB

Permalink Reply by Louis Dupleix on November 9, 2017 at 8:34am

Thank you Joseph, indeed it is better. But it doesn't work with the boundary. The final shape doesn't appear

Permalink Reply by Joseph Oster on November 9, 2017 at 8:41am

Sorry, I don't understand?

P.S. It might make more sense to reduce the rebuild count and sacrifice detail for the sweep sections, provided the original curves are used to place those 'Boundary' surfaces (with holes) at each of the eight "stations"?

P.P.S. I just noticed that I disabled the 'Preview' components in the file I posted; did you re-enable them?

Permalink Reply by Louis Dupleix on November 9, 2017 at 9:31am

I re-enabled them, it was that (beginner error...)

I don't get how to make those boundary work

Permalink Reply by Joseph Oster on November 9, 2017 at 9:51am

I don't get how to make those boundary work

Do you mean you don't want them in the final printed result? Or don't know how?

They may not be appropriate or look good or may be impossible to 3D print (esp. with the holes), I don't know. And the details that I see being lost when the rebuild count is reduced from 400 to 80, for example, might be impossible to see anyway, so maybe it doesn't matter.

This is more of an art project than some models so be sure to explore all the parameter settings to see what you like best.

Permalink Reply by Saam on November 16, 2017 at 10:16am

Hi Joseph,

Could you send the final model again please with enabling the preview. I tried to enable the preview but can't figure out how!!

Thanks

Permalink Reply by Joseph Oster on November 16, 2017 at 10:38am

Using preview is a critical basic skill in Grasshopper.

I can't be sure this copy is identical to what I posted; I try not to make any changes after posting code but sometimes I do. You could enable previews on Zoetrope_2017Nov7b.gh.

Attachments:

Zoetrope_2017Nov16a.gh, 34 KB

Permalink Reply by Saam on November 16, 2017 at 10:50am

Thanks Joseph,

Yes, I tried that before and this is what I get. I thought I could be able to see the whole outcome model. including the body figures and motions

Permalink Reply by Joseph Oster on November 16, 2017 at 11:09am

It looks like you have clicked this green icon? Don't do that.

Really, this is so fundamental... Is the GH code indecipherable to you?

Permalink Reply by Saam on November 16, 2017 at 11:21am

I am not familiar with grasshopper that much, but I really need this model that is why I am trying to get hang of it.

I double checked and I have not pressed that green icon.

There is another file on the first page of this thread which when I open , it shows the whole model.

Attachments:

Untitled-1.jpg, 1.3 MB

Permalink Reply by Joseph Oster on November 16, 2017 at 11:41am

I can't see over your shoulder. Are you using the same Rhino file you posted originally? zoetrope.3dm

I am not familiar with grasshopper that much, but I really need this model that is why I am trying to get hang of it.

That statement does not motivate me at all. To the contrary, in fact. Please read #7 on this page:

http://www.grasshopper3d.com/forum/topics/how-to-get-help-when-you-...

7. This is not a 'do my work for me' group
Many of us like to help, but it's good to see effort on our part being matched by effort on your part. Questions in the form of 'I need to do X but cannot be bothered to try and learn the software' will (and should) go unanswered.