How to create a "bulging" pattern?

[nikkwong0]

Hi guys, please see the attached file.

I cannot figure out how to create a diamond pattern like so which "bulges" out in the middle.

Can someone please offer me some advice?

Thank you. 

[jhackney1972]

First, you will have to build the domed part.  I did not see a radius for the dome, I just made one up.  Create a domed surface, then extrude to it.  See attachment 1 and 2.  Then you can create a sketch on a plane above it, and create a 3D sketch and project to the surface.  I did not sketch the complete pattern,  just enough to give the idea, see attachment 3.  Part is attached in another answer, only have three attachment per answer.  I did not calculate the arc cutout because it depends on an accurate pattern layout.

[jhackney1972]

Here is the file.

[nikkwong0]

You are a genius! Thank you sir! 

[nikkwong0]

Hey there,

I'm kind of confused.

In the file I attached the faces are 'faceted'. I think the technique you provided will just place the lines on the dome but in a non faceted manner. How to actually make them faceted? 

[jhackney1972]

I did not take the time to sketch the sketch lines in the other direction, they would be done the same way to make the pattern you show.  If you want to continue modeling after that, each 3D sketch could be used to sweep a feature, positive or negative, to the surface.

[johnsonshiue]

Hi! The bite-off cookie shape should not be difficult. The tricky part here is the cut pattern. There are many ways to do that. Attached is one of the ways that use possible the least amount of features. I have to say this case looks like a school assignment to me. If it is, please consult with your teacher and your teammate first.

Many thanks!

[WHolzwarth]

I'm struggling with something like this, but I'm having problems with stability.

Perhaps I'll come back later.

[WHolzwarth]

Now going on. Most of the task is done from my side.

But Autodesk should inspect, why Boolean combine of the remaining bodies is not possible.

2018 IPT attached.

[WHolzwarth · Accepted solution]

Sometimes dumb solids are more intelligent than parametric ones.

Here stepping out and back in solved the issue.

But filleting the zigzags at the outer diameter seems like  a challenge

[johnsonshiue]

Hi Walter,

I suspect it is a near-tangency issue in Boolean. I agree with you that it should work. I am able to simplify the files so it is easier to reproduce. I will work with the project team to understand the behavior better.

Many thanks!

[S_May]

[S_May]

Ich hab mit dem Modell so meine Probleme, denn die Anordnung solch einer Struktur in zwei gekrümmnden Acshen würde an den Polen zu einem "null" Punkt führen.

Das heist um es auf das Modell zu übertragen müsste man jede Raute+Erhebung einzeln darstellen. Einfach trennen (wie ich es gemacht habe) ist falsch.

Eine Anordnung kann es nur am Äquator geben, und nach N und S jeweils versetz um den Breitenkreis.

kelly.young has Translated With Google Translate:

I have my problems with the model, because the arrangement of such a structure in two curved Acshen would lead to a "zero" point at the poles. That is to transfer it to the model one would have to represent each lozenge + elevation individually. Just disconnecting (as I did) is wrong. An arrangement can only exist at the equator, and after N and S each offset by the latitude.

[S_May]

noch schlimmer, es hat zwei Pole:

[WHolzwarth]

Surely there are two poles for tasks like this, Sascha. It's normal. Look at Mother Earth. But the main axis for the poles can be placed everywhere on the sphere.

IMO my solution is hard for being improved.

[nikkwong0]

Thank you so much everyone! For reference, it's not for a school project, it's for my company (www.getfractals.com). 

Thrilled to have so many bright minds helping me where I failed. Will take another stab at it tonight and post the results! 

[S_May]

sorry I have prescribed myself, it should mean there are 4 poles

[nikkwong0]

This is great! But I'm so confused as to how this shape was made (selected in white)—it just shows up as "solid"—any clues here? I usually see complicated shapes like this created through steps instead of just one "solid" which I can't really inspect!

Thanks so much.

Reminds me of — 

Hahaha. Sorry couldn't help myself. 🙂 

[nikkwong0]

Just saw the original attachment from wh—thank you. I'd like to send you a tip, if you have Paypal, please DM it to me—I didn't know this would be so much work—surprised there's not an easier way—very much appreciated!

[kelly.young]

@nikkwong0 There are plenty of good ideas on how to go about drawing this, thought about it and it is indeed troublesome where the "poles" are located. If it isn't exact there is a tiny bit of overlap where they meet and not a seamless transition.

I went about doing this the same way I would do a cylinder knurl with sweep but had to setup for a spherical surface.

Check out the attached file and also turn on the iLogic browser, it should allow you to change size settings (small increments so it doesn't break dimensions).

I am still thinking of a way to make it knurled all around without breaking into triangles. Teaser: was making fancy ornaments for tomorrow's Friday Pictures.

Hope that helps!