Modeling a hollow sphere...??

[Daf]

Hey guys!

2 part question please ... :

1 What is the best way to create a hollow sphere? The inside of the sphere will be visible (see below) in one section.

2 Pertaining to the above ... would also need to cut out a section as a "hatch" - best if section of sphere could be used so as to maintain the contour and have it look like it was cut out of that section. This will be an actual hatch or door into the sphere.

Any suggestions? I'm afraid that using a boolean to create the "hollow" would cause problems later when trying to extract the hatch piece??

I'm using Max 9 Design.

Thanks!

Daf

[Steve_Curley]

Nothing below to see?

Create a sphere, convert to Editable Poly. Select a poly (or a small group of polys) to act as the "hatch" > Detach > To Element. Exit SubObject Mode, apply a Shell Modifier, Outer Amount 0, Inner Amount as much as you need. Add an Edit Poly Modifier, select the Element which you selected earlier and move it out of the way so you can see the results.

One word of caution - you may find that when the hatch is closed the outline of it will still be visible. This is because the normals of those polys will not match the polys at the side of them even if you give them all the same smoothing group. This may or may not be an issue, depending on what you intend to do with this once it's finished.

p.s. There's no such Max version as "Max 9 Design". Max 9 had no Design version, Max 2009 was the first release to offer such a choice.

[Daf]

Hi Steve - thank you!  I'll give that a try!

by "see below" I actually meant the bit about the hatch and how it related to the sphere - sorry for the confusion. 🙂

[Daf]

Okay - follow up to the hatch ...

In attached pic - I have the faces of the hatch selected but not yet detached - how can I make the corners, of both the hatch and the subsequent hole, rounded?

Thanks!

[Steve_Curley · Accepted solution]

Ahh, I was expecting an image 😉

Rounded holes on a curved surface are tricky - possible, but at the cost of increased poly count. I would reduce the segments of the original Sphere as far as possibe while still being able to select a suitable number of polys to create a hole of the right size.

After converting to Poly and selecting the polys, Detach to Object rather than to element - makes it easier to hide/show them, and also easier later on if you want to animate the hatch opening.

Collapse the stack on both objects (or Convert to Poly). Select the hatch object and hide it. Select the edges around the inner and outer of the hole, but NOT the edges which run through the object (see the image). On the Edit Edges rollout change the Crease value to 1. Turn on Nurms Subdivision (on the Subdivision Surface rollout - I used 2 iterations but you may need more - each iteration will quadruple the poly count which is why I suggested lowering the original number of segments on the sphere.

Hide the sphere and unhide the hatch. Repeat the above on that then unhide the sphere. In the last image you'll see the outline of the hatch on the sphere - that's what I was referring to earlier and is extremely difficult to avoid.

[Daf · Accepted solution]

That, sir, is perfect!! The outline is fine.

Thank you so much!

Daf

[Steve_Curley]

You're welcome - glad it helped 🙂

[Anonymous]

I only use AutoCad LT, but now have need to design on a spherical object.  I need more of a graphic tool, to do lettering and image creation, to be loaded into CNC software.  What version of AutoCad would I need to purchase for this work?  Thanks, Doug