# How to create an excellent and complete shell of a sphere

This morning I have tried to create a shell of a sphere (see the figure).

However, I would to have the entire shell where I can see to complete revolution on the other side of the sphere. What should I do?

• What is not clear it's what do you want to do
– user120647
Jun 17, 2018 at 22:20
• @Danielillo I would like the complete circumference for each arc I drew by showing it also on the other side of the sphere (the arc on the other side must be dashed). I have upvoted you for your disponibility. Jun 17, 2018 at 22:24
• Is there a similar image on internet about how it should look at the end?
– user120647
Jun 17, 2018 at 22:32
• Similar a complete tape (shell) encrypted-tbn0.gstatic.com/… or dribbble.com/shots/1675477-Sphere-Rings. Now is it more clear? Jun 17, 2018 at 22:38

If you want perfectly round stripes, revolve a splitted half circle, a group which consists differently colored pieces. An example:

Here all stripes are equally wide. As well you can at first make a circle and split it arbitarily

1. Draw a vertical line (=hold shift as you draw)

2. Make a rotated copy (Object > Transform > Rotate > 15 degrees, Copy)

3. Draw a circle which has center at the crossing (Hold Alt+Shft as you draw, be sure that you have smart guides and snap to points ON, no other snaps!)

4. With the Scissors tool split the circle at the crossings, delete everything else than the 15 degrees arcs

5. Make rotated copies until you have a full circle (Object > Transform > Rotate > 15 degrees, Copy, repeat by pressing Ctrl+D)

NOTE: 15 degrees was selected because it's integral part of 180 degrees.

1. Delete the left half of the circle, color the remaining arcs and group them

2. Revolve the group to make a sphere

If you want different division to stripes, you can in step 2 make more marking lines with different rotation angles. After inserting the circle you split it at the crossings.

EDIT 20 months later:

The originally wanted thing was to draw cutting lines when a spherical surface is cut by 2 parallel planes. Those lines in 3D are circles. In 2D projection they are ellipses. Both ellipses have same proportions, so the bigger can be made by scaling a copy of the smaller:

There's no generality loss to draw the ellipses horizontal. The image can be rotated later.

The ellipses are tangential, both of them touch the circle on 2 points. Believe or not, it's possible to construct tangential ellipse exactly in Illustrator by applying geometry (see NOTE1), but for all practical purposes they can be placed by eye. Only have fine enough arrow key nudge increment set in the preferences.

Ellipses are cut in the touching points with the scissors and the hidden halves of the strokes are changed to dashed ones. The cut point isn't a node, disable Snap to point temporarily to be able to use the scissors in the right places.

NOTE1: it's based on projective geometry. There such things as tangency, being the same point and sitting on the same straight line stay invariant when a plane is projected to another.

In a plane we can construct a tangent line to a circle in the wanted point. As well we can draw a circle which has a given line as the tangent at a given point.

By non-symmetric scaling we can simulate plane to plane projection in Illustrator. We can scale temporarily so that the wanted ellipse becomes circle. That circle has common tangent line with the original circle which has became to ellipse (temporarily).

There's several possibilities to colorize the result. The band between the ellipses can be filled with the Shape builder. A copy of the circle can be filled with a gradient as you originally did. The filled band can be used with blending mode to retain the underlying gradient shading. The dashed lines can simply be laid on top.

• Thank you for your contribute and for the file. I have tried for 4 hours and I have obtained this file Ai that I sent you in this link:ufile.io/2htwq. The problem is only the step 4) (With the Scissors tool split the circle at the crossings, delete everything else than the 15 degrees arcs.) Where I can find the Scissors tool into the italian menu? My works not is very eccellent as your picture. Thanks a lot for the file. Thanks of my heart and I have spent 4 hours for the picture :-) I have not understood my downvote. good work. Jun 19, 2018 at 20:00
• @Sebastiano In the toolbox scissors are hided under the eraser. About downvote: Someone thinks that you are lazy or he simply was frustrated because he wants to see some finer discussion of artistical reasoning. Technical receipes are not his favorites. We can only guess, because every member can vote as he likes without explanations. BTW thinking one random vote is a waste of time. Draw something instead. Your linked attempt shows that you are not lazy. Jun 19, 2018 at 20:38
• Kind user287001. I'm sorry I'm only answering now but I'm very busy these days. I'm not at all lazy :-) and I can guarantee it to you. Often I go not to race but much more than just to race. In my initial question I drew something and inserted the image. I also learned with you where the splitter is (by pressing ALT). I thank you very much and, as you can see, I also voted for your answer instantly. Thank you very much. Jun 27, 2018 at 20:14
• Hi, excuse me. Why have I obtain differents downvotes on an old questions? I have differents downvotes. Apr 6, 2020 at 20:53
• Unfortunately only the downvoters themselves know. I wouldn't be especially worried of downvotes, I collect them, too. Votes nor downvotes are not money. More harmful have been those cases when I have been laid off (=account locked a month at a time) after a drawing that I thought to be humorous. Maybe all of us do not use this site for fun. Apr 6, 2020 at 21:08

Starting with three shapes

• Semicircle
• Big circle
• Small circle

• Select the Big circle and the Small circle
• Menu Object > Blend > Make
• Menu Object > Blend > Blend Options > Specified Steps = 6

• Select the blend and drag it to the Symbol Panel to transform it into a symbol

• Select the Semicircle > Menu Effect > 3D > Revolve

• From the revolve window options, click on Map Art
• Choose the symbol, make it bigger and relocate it

• Sorry, I already delete it. Tell me which part are you unable to make it on your own, I think the explanation is a very clear step by step...
– user120647
Jun 18, 2018 at 10:18
• If you put Adobe-Illustrator as a tag, we assume as clear that at list you are able to make a Semicircle, Big circle and Small circle. If that's not the case, I invite to add a question asking how to make a Semicircle, Big circle and Small circle in Adobe Illustrator.
– user120647
Jun 18, 2018 at 11:31
• @Sebastiano On the other side, I have been very correct from the beginning with you and your question and I agreed to answer you immediately creating a more than complete step by step about how to solve your problem. Since this is not the answer you expected, fortunately the question is still open, so I also invite you to wait for an answer that better fits what you need. I Hope this comes as soon as possible.
– user120647
Jun 18, 2018 at 11:31
• It is not possible to see who votes what, post another question with your issue. At the question you can add a link to the original question. And remember this is a site to solve Graphic Design questions, not a personal tutorial service or job request for free.
– user120647
Jun 18, 2018 at 11:41
• I have thanked you. I have never thought at all that this site or others are made for a personal tutorial service or job request for free. It's only 7 hours that I'm trying but I can't do it like you. That is why I asked you. Jun 18, 2018 at 11:46