Sphere3d substitute

[tlillehoff]

I have been trying to use different geometry types for modeling, and i have created a page for that research. heres what im working on. http://www2.zbrushcentral.com/zbc_uploads/user_image-1033744836ahx.gif

http://www2.zbrushcentral.com/zbc_uploads/user_image-1033744858pvz.gif

[Rafael Hernandez]

This sounds very interesting. But, could you elavorate further what you are trying to acomplish and how you are going about it. Keep us posted.

[Antimorph]

This is very clever tlillehoff, thanks very much for sharing this.

[tlillehoff]

rafael,

basically, i was thinking to myself, while using a sphere3d, and trying to spread the points around the poles out so i could use the extra geometric resolution.....I thought that starting with an object with more equally positioned points would make it easier to model. plus...no pinching on the texture

[Rafael Hernandez]

But how do you accomplish this within Zbrush? Or do you create this in another program?(If you wanna keep it to yourself, I understand). I tried skinning a zsphere but you cannot get the smooth results that you have accomplished.

Also, can you create low polygon lillehoff spheres?

Edited: Never mind. I just went to your site. I'll spend some site studying the scripts. Thanks for sharing.

[aurick]

You took a Sphere3D and made a unified skin from it at the lowest possible resolution, is that correct? It's a very interesting idea!

[tlillehoff]

no..actually i took a dodecahedron, used a catmull subdiv rounding algorithm on it to convert the 5 side polys to quads, then just brought it into zbrush and divided and smoothed it. i didnt even think about doing that. i should see if it gives the same result.

[Zoid]

When I saw this the first thing I thought was if modeling with symmetry would be a problem, but it works beautifully. Here's a quick example. Your sphere is on the left.
http://www2.zbrushcentral.com/zbc_uploads/user_image-1033757902xgz.jpg

I like how the mesh curves around with the shapes of a face. Another thing, when you mask and divide a regular sphere the division lines extend out and around the whole sphere, but with your .obj file the divided mesh stays within the mask. Thanks for doing this, I really enjoy modeling with it.

P.S. Do you know that Hoberman guy by any chance? :)

[tlillehoff]

also...i dont know if you work with nurbs/patches....but the quilted topography of the lillehoff sphere might make it alot easier to convert the polys into a closed nurbs/bezier patch surface. and That would be something.

yeah i thought if hoberman and ol buckminster could have their own spheres, why cant i have one too ;)

[Zoid]

I have Amapi which has nurbs. If I can import it it will be interesting to see what happens. Plus as you said, texturing might be different with this kind of mesh. All fun stuff to test out :cool:

[Mentat7]

lol! Aurick already mentioned what I was going to say. Anyway here is a pic of it. A Sphere3D skinned using Unified Skinning set at a resolution of 16 with Smooth set to 100. I then applied TOOLS>DEFORMATIONS>SPHERIZE several times to turn it into a sphere.

http://www2.zbrushcentral.com/zbc_uploads/user_image-1033760188mcu.jpg

[Grub]

I like your tool Tlillehoff; it's nice and neat to work with.
For some reason, I found myself modelling cats and dogs with it...
:tu: :tu: :tu:

[Kaz]

In the old days, Pix descibed something like this:

In Notepad, type this:
v -1.0 1.0 1.0
v 1.0 1.0 1.0
v 1.0 1.0 -1.0
v -1.0 1.0 -1.0
v -1.0 -1.0 1.0
v 1.0 -1.0 1.0
v 1.0 -1.0 -1.0
v -1.0 -1.0 -1.0
f 4 3 2 1
f 3 7 6 2
f 7 8 5 6
f 5 8 4 1
f 8 7 3 4
f 6 5 1 2

Save it with an .obj extension, then import it into Z. Divide the object a few time and spherize a few times...
http://www2.zbrushcentral.com/zbc_uploads/user_image-1033782843hgc.jpg

[tlillehoff]

exactly,

but the problem with that i that your starting with a cube. a cubes points are not equidistant from a center and thusly you will get that bunching of points.

If you start with a more spherical shape your divisions will be more even.

http://www2.zbrushcentral.com/zbc_uploads/user_image-1033824105sfo.gif


also..you see the star junction? That is a commonly used connection point for multi patch surfaces as well as the 4x4 array of points in a patch that can easily be replicated as a bspline.

[milk]

How do you get to the grid like that?

[tlillehoff]

shift-f

[milk]

When I did that, the whole screen just turned white.

[milk]

Whoops, I pressed ctrl+f.... :p

I still can't get it to work though...

I can't wait till ZBrush is a really big program (which it will be some day) and there are books on it. :D

[tlillehoff]

in preferences

hit the Pf button

aka draw polyframe

[aurick]

If you're using the demo, you can't get a polyframe view. That is only available in 1.5.

[banez]

my symmerty got messed up LOL :D
http://www2.zbrushcentral.com/zbc_uploads/user_image-1033834559bhs.jpg

[Northstarr]

Whew! This is all over my head! Just wondering though, what is the advantage of doing this??

:qu:

[tlillehoff]

well...the main advantage for zbrush users is that this sphere has points that are more evenly distributed over the surface of teh sphere so you dont get the deformations and pinching when you model, because the bunching of points on a sphere 3d.

the 2nd avantage is that the lillehoff sphere is configured in a way that replicates the way one would model a sphere using b spline patches. ( you can have a bspline sphere, but it looks like the sphere 3d and you run into the same problem with points on the poles) Theoretically, you would be able to convert between the 2 geometry types.

Because zbrush is a polygonal modeling/paint tool it doesnt apply. but if you were using another program like maya, xsi, max, or lw it would very applicable.

Nurbs/Poly conversion is still very much a hot topic and this implementation might be very usefull becuse you would be able to exactly reproduce the points on the surface giving a very close approximation of the original surface.

Of course im still working on this part, as a script that will autodetect the star junctions and create patches basedon the number of points between them and then connect them all together, and export as an .iges

whew.. ;)

[leobia]

Can someone repost the lillehoff Sphere?....It's very usefull but I lost it....the link of tlillehoff doesn't work :rolleyes:
Thanks in advance :)

[rtwolfenstein@hotmail.com]

nice idea tlillehoff but i dont think you are the one who thought of this idea first since kircho had already posted a zip file with spheres similar two yours in my old post...

[Antimorph]

tlillehoff posted this three years ago. I'm uncomfortable about re-posting the obj. Any mathematicians here who could recreate this?

I wonder if tlillehoff would feel disenfranchised if someone were to repost.

[rtwolfenstein@hotmail.com]

Oh, im sorry then i thought he had just thought of it today sorry...

[billrobertson42]

You can start one in wings 3d.

Step 1: get wings 3d (http://www.wings3d.com/), install, start program ;)
Step 2: right click on the screen, and click dodecahedron.
Step 3: go into object mode (click the all red pyramid icon in the top/middle of the screen)
Step 4: select your dodecahedron and subdivide to your heart's content -> hit 's'
Step 5: File: export: Wavefront (.obj)

There will be some poles in there still. You might be able to bring it into zbrush and sphereize/smooth it with the deformers to get rid of those.

*edit* the icosohedron seems to give a bit better results, but it's still a bit lumpy.

[Kircho]

This (http://www.zbrushcentral.com/zbc/showthread.php?t=30785) is the thread rtwolfenstein is referring to. For those interested in using a sphere of custom geomtry for modelling, I don't recommend tlillehoff's sphere. In the aforementioned thread I describe why and present what I consider to be better solutions.

Kircho

[leobia]

Thank u all for your replies.....your models are very good Kircho :tu:

[Svengali]

I don't think T. Lillehoff would mind so I'm posting an old .ztl file with one of his primitives... I've used it a number of times myself.

Sven

[aminuts]

hi Sven,

Haven't looked at the tool yet but is it the sphere/cube one that was available back in 1.55b. Someone posted a script for it long ago....thought it was Southern but couldn't find it in his threads.....it might even have been an included script in 1.55......just remember it was terrific...no poles....for starting a head with a sphere.......even seem to remember it had more poly's on one half for the face.

If this isn't it....do you remember the one I am talking about? Do you still have that script laying around? Was trying to find it for someone but can't find my old 1.55 cds at the moment.

[billrobertson42]

Hi Svengali, It turned out that smoothing one of the wings polyhedrons worked out pretty well after a minor application of the spherize deformer in zb.

It was an interesting experiment.

*edit* for curiosity's sake I created the dodecahedron in wings, subdivided 3 times, imported into zb, applied a sphereize 100 to it.

[--E--]

Some cool stuff on this thread,

I also didn’t much like the default cube3D and really didn’t like the default sphere3D because of the holes and bad geometry.

here are my default cube3D and sphere3D both made from the original cube3D mesh that came with zbrush

you will have to do a spherize on the sphere3d to get it to be perfectly round, but other than that, their geometry is much cleaner for modeling.

here (http://www.ericblondin.com/zbrush/forum/sphere3DandCube3D.rar)

[lazygenius]

I have also been trying to create nicer spheres by subdividing basic geometry. However I always have a problem when it comes to generating texture coordinates - my textures always get pinched at the north/south pole or I get problems at longitude -180/180 degrees.

Does anybody have any ideas on how to create better texture coordinates please?