Jump to content

Sign in to follow this  
CApruzzese

adding octagon geometry to a sphere

Recommended Posts

I am making a model of the Aries Shuttle from 2001: A space Odyssey and the top of the sphere has and octagon extrusion but I'm not sure how to do that. I think a hexagon spline and her projected onto the sphere somehow then I could me my selections and extrude. I operated the top of the supers so I could make a bump map and do it that way if I have to. But I would rather it be real geometry. I have wanted to model this for years and this little problem has always been the thing that stopped me! 

 

Thanks for any help anyone has to give! 

hexagon on sphere.jpg

Share this post


Link to post

image.thumb.png.ab1cfeebcb38882a5ea647d19297838a.png

Like that? (Okay, I just noticed it's a hexagon, but the principle is the same)

 

Choose some subdivision for your sphere that is dividable by 8*2^n on the circumference, just for the ease of use. (Here, I of course use 6*2^2 since it's a hexagon.)

Create octagonal splines and subdivide them so the number of points is the same (each line has 2^n points; I chose a power of 2 so you can just subdivide easily.) Align splines with the subdivision of the sphere, and choose the size so the projection will work.

Project the splines on the sphere. The resulting points should almost align with the subdivision of the sphere.

Move the next sphere points to the spline points (vertex snap) one by one. If the mesh of the sphere is too dense, move some edge rings out of the way.

Now two edge loops of the sphere should align with the splines. Sadly, this has distorted the adjacent polygons and lengthened some edges so the sphere does not look so spherical any more.

Cut the sphere poly loops close to the hexagon if necessary.

Use the Spherify deformer to get all points back onto the theoretical sphere surface (same radius as the original sphere, 100%).

Now you can extrude the hexagonal poly loop.

 

And now we wait for the answer of a real modeler who does the same in three seconds and depress me 😉

 

Share this post


Link to post

 

1 hour ago, Cairyn said:

And now we wait for the answer of a real modeler who does the same in three seconds and depress me 😉

 

Oh no - nothing quick and easy about that - in fact I would say it is one of the hardest challenges in modelling to get this right, and do to so with subdivision surfaces involved needs a fairly high level of modelling skill and a lot of patience and running round the houses to get a deformation-free result...

 

Cairyn's way of doing that totally acceptable, at least until it comes to adding SDS  😉 At that point you will find you have a massive problem trying to construct those hard edged square shapes right where you have an unhelpful pole at the top, in the center of the hexagon indent.

 

CBR

Share this post


Link to post
11 minutes ago, Cerbera said:

until it comes to adding SDS

 

waaah, don't say the evil word!

 

In fact, with the amount of flat surface detail on this model (there is obviously much more than just this octagon) I would not apply any SDS at all, but brutally cut the details into the sufficiently subdivided sphere model or move the points around as outlined; keeping the spherical form with the Spherify deformer; then extrude the details, then apply bevels manually. The SDS would just ruin the hard edges of the large scale items.

 

For nurnies and greebles, I'd even mash objects together recklessly, unless this is a 3D print model that needs a defined shell. (Actually, my 3D printer's software can handle intersections, even.)

 

Share this post


Link to post

Lols, yep good thinking there 🙂 I too would be keeping SDS in the box for this one !

 

CBR

Share this post


Link to post

I am going to try some of that out Cairyn! I have been using the bevel tool with selections to make the rounded edges where I am want them. I added a generic grebe bump I made for some other  2001 models and i'f I wasn't sold on the octagon thing as it is in the film version, it would be good enough to use. I am not trying to 100% precise copy of the model, but I want to push it towards something I will really like. 

 

Cerbera... is that HAL as our avatar? It seems appropriate for this discussion! 

aries bump map.jpg

Share this post


Link to post
45 minutes ago, CApruzzese said:

Cerbera... is that HAL as our avatar? It seems appropriate for this discussion! 

Yes that's there to remind you all that I can turn off your oxygen at any time 🙂

 

CBR

Share this post


Link to post
3 hours ago, Cerbera said:

Yes that's there to remind you all that I can turn off your oxygen at any time 🙂

 

CBR

Please turn i toff soon, I need the rest! 

I was just looking at using the projection feature to project my octagon on the surface of the sphere then extrude it slightly to get the effect I want. It could work I think. 

Share this post


Link to post

OK I cheated big time. This went from fun to frustrating so decided to just cut the upper octagon section from a lightwave version of the ship, delete polys and move around points and boole in my windows on top. This will work for what I need it for right now which a series of 2001 posters I am doing highlighting one ship in each (And HAL, of course). I think at later date when I'm not so stressed out, I'll redo the landing gear completely so they can retract and do more work on the details. Now I have to work on the textures, the reflectivity and the lighting and find a really striking shot to put in my poster series. 

 

Thanks you guys for your input and help! 

Aries 3 shots.jpg

Share this post


Link to post

The final product.  I did do a little more detailing.

2001 Poster V7.jpeg

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...