How to create a hollow sphere with holes?

uqlcai1
Contributor
Contributor

How to create a hollow sphere with holes?

uqlcai1
Contributor
Contributor

My end goal looks something like this:

uqlcai1_1-1722857903762.png

 

My attempt's steps:

  1. Create big Geosphere
  2. Create small Geosphere
  3. Convert big Geosphere to Editable Poly, then select all polygons, detach as element
    1. Intention is so that it becomes a hollow 2D surface, so that boolean later does not just create dimples
  4. Scatter the small Geosphere onto the big Geosphere, at all vertices
  5. Boolean subtract all the small Geospheres from the big Geosphere
    1. Stuck here - the whole thing (all spheres) just disappear
  6. If step 5 was completed properly, I would Shell to add some thickness, yielding the final results.

 

Could anyone give some pointers on step 5? And/or if this intended workflow is on the right track at all?

 

I have attached my WIP .max file as well.

 

Note: As opposed to the common tutorials for hollow spheres (e.g. this video), I need very circular holes. Following that guide (and variants of it), my holes end up triangular, lop-sided, etc, to a degree seemingly unfixable by TurboSmooth.

 

 

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wernienst
Collaborator
Collaborator
Accepted solution

My attempt is a bit different:

Create a big Geosphere. Make a copy and hide it. Set Segments low for scattering. Create a small Geosphere. I use Array Modifier for scattering.

wernienst_0-1722875817322.png

Convert the sphere array to a single Editable Poly. Remove the big Geosphere.

Unhide the other big Geosphere and increase the Segments value (not to high!). Now substract the array from the big Geosphere.

wernienst_1-1722876408004.png

Convert the result to a Editable Poly. In polygon subobject mode, select the remaining big Geosphere polys by using By Angle: 5.0

Invert the selection and remove these polys.

wernienst_2-1722876811503.png

In Object Properties, notice the Faces count. Now add a Retopology Modifier, set Face Count at least twice the count you've just noticed. Keep all other options at their default. Hit Compute. Now you get an object (almost) perfect for your demand.

wernienst_3-1722877167919.png

Here I've added a Shell, then a Turbosmooth Modifier, Iterations: 2

wernienst_4-1722877312414.png

 

uqlcai1
Contributor
Contributor

Thanks! I am following workflow, I couldn't get retopology to work like it does for you. I've tried face count x2 and x3, the result remains irregular, like this: 

uqlcai1_0-1722940361258.png

 

This couldn't be fully fixed by TurboSmooth/OpenSubDiv, the holes remain quite irregular:

uqlcai1_1-1722941365162.png

 

3ds max also froze for hours (rest of the computer seemed fine) while doing the Boolean... I've attached my .max attempt again, could you please have a look and see where I've gone wrong? 

 

Also, would you mind attaching your file as well? In case my attempt freezes for a few hours again...

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wernienst
Collaborator
Collaborator

I'd say your Big GeoSphere has too few segments. As I said, use one for distributing the little spheres and another one with more segments for the Boolean operation.

Here is my attempt. I've reconstructed it using Modifiers as much as possible because I deleted my original file.

Scene loading and building will last about 20 seconds. 3dsMax 2024 or higher required.

 

Edit: Done some corrections

uqlcai1
Contributor
Contributor
Thank you! I was afraid to increase the segments more than I did, fearing the freeze in later steps, but it looks like that was really the issue.
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domo.spaji
Advisor
Advisor

Geosphere (icosa)

Chamfer mod. - All verts - Open chamfer

Turbosmooth

Spherify mod.

Shell

 

You can go back and change all parameters to your liking

wernienst
Collaborator
Collaborator

@domo.spaji  Big 😊👍!

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uqlcai1
Contributor
Contributor
Thank you! Learning new ways to reach (sometimes mostly) the same results is one of my favourite things, great balance between familiarity and novelty.
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