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General Category => General Anim8or Forum => Topic started by: Kyle on September 14, 2014, 02:37:42 am

Title: Default spheres looking more like ovals?
Post by: Kyle on September 14, 2014, 02:37:42 am
Hope I'm explaining this right but I just noticed something at random and was wondering this has always been the case.  A sphere should be a perfect sphere shouldn't it? When I make a sphere, regardless of how many divisions I put in it or how many times I subdivide, it doesn't look perfectly circular.   I can go to the top view and rotate it on the Z axis and it looks fine, the outline stays consistent at any degree I turn it, yet if I go to the front, left, or right view and rotate it along the same axis I see that the height is longer than its width.  Is that normal?

I can post screens if needed.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on September 14, 2014, 02:51:04 am
Hi Kyle,

Try this sphere. Just put it in your plug-in folder and restart Anim8or. You should then be able to find it on the plug-in toolbar.
Title: Re: Default spheres looking more like ovals?
Post by: Kyle on September 14, 2014, 04:10:13 am
That's one way to do it. Though this topology would make it more difficult to work from for certain things. I get the point, it helps make the surface smoother.

I just find it strange if the dimensions of the built in primitive has been wrong all these years.

Is there a plug in like this somewhere that uses square faces instead?
Title: Re: Default spheres looking more like ovals?
Post by: CrashDrive on September 14, 2014, 04:42:48 am
Yup. It's height is greater for me too. Imported one from  V97 and same. Imported one
from a different program and it was perfect all sides. So the ruler is accurate at least.
Title: Re: Default spheres looking more like ovals?
Post by: jwalt on September 14, 2014, 01:13:38 pm
Got me curious enough to take a look, and the default sphere seems fine on my system. Just a passing comment.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on September 14, 2014, 01:21:50 pm
The problem that I have with the default sphere is that textures are always distorted near the axis. But I see what you mean about the topology.
Title: Re: Default spheres looking more like ovals?
Post by: Kyle on September 14, 2014, 08:00:28 pm
Got me curious enough to take a look, and the default sphere seems fine on my system. Just a passing comment.
Maybe you should upload one so one of us can take a look. I can't imagine a sphere made on yours looks fine but not on ours.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on September 14, 2014, 09:13:36 pm
Kyle,

Here is another sphere plugin similar to Anim8or's default sphere. It is a Blender sphere. I'm not really sure it is better than Anim8or's sphere. Give it a try.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on September 14, 2014, 10:30:46 pm
I was just checking out Anim8or's native sphere plugin using the new CAD ruler. I see that in front view, the "Y" dimension measures a bit longer than "X" when there is an odd number of latitude divisions simply because the ruler measures from face to face in "X", and point to point in "Y." As you would expect, a sphere with an even number of latitude divisions measures the same in "X" as in "Y." The plugin seems to work correctly, for me at least.


The reason I don't ordinarily use these spheres is because they look odd near the poles when subdivided, especially when textures are applied.
Title: Re: Default spheres looking more like ovals?
Post by: jwalt on September 14, 2014, 11:10:11 pm
Maybe you should upload one so one of us can take a look. I can't imagine a sphere made on yours looks fine but not on ours.

I hadn't realized you folks were talking about textured spheres, so my comment is worthless. I'll have to pay more attention. Probably has something to do with those pesky triangles near the poles.  ;-)
Title: Re: Default spheres looking more like ovals?
Post by: Kyle on September 14, 2014, 11:32:41 pm
The other plugin seems to create a perfect sphere on my end. Though it doesn't completely replace the built in one for two reasons: one, it doesn't allow me to change the divisions that I can tell, and two, at least in the beta the center axis seems off somehow. It rotates fine until I let go, then its coords completely change for no reason. But again that could be a bug in the beta.

I hadn't realized you folks were talking about textured spheres, so my comment is worthless. I'll have to pay more attention. Probably has something to do with those pesky triangles near the poles.  ;-)
Textured or untextured, it shouldn't matter.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on September 14, 2014, 11:40:34 pm
Here is a plugin for a blender quad sphere if you are interested. I particularly like this one.
Title: Re: Default spheres looking more like ovals?
Post by: jwalt on September 15, 2014, 12:00:05 am

 Textured or untextured, it shouldn't matter.


I subdivided (smoothed), and now see what you are talking about. I hadn't noticed this before.
Title: Re: Default spheres looking more like ovals?
Post by: Kyle on September 15, 2014, 12:12:08 am
Here is a plugin for a blender quad sphere if you are interested. I particularly like this one.
That's an interesting one for sure. Probably one of the more useful ones Ive seen so far.

Still hoping to find a good replacement for the built in tool though.
Title: Re: Default spheres looking more like ovals?
Post by: cooldude234 on September 15, 2014, 12:26:48 am
Yea maybe Steve will look into fixing it. At least fix the UV coordinates for the Geodesic spheres, that way I could have a planet without its attic caps looking like a swirly ice cream cone :P
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on September 15, 2014, 12:33:05 am
Yeah, now I see what you mean. The Anim8or spheres don't subdivide very well. I think you are going to have the same problem subdividing any sphere constructed with longitudinal vertices converging at poles. It seems to me like it has more to do with subdividing than the spheres themselves.
Title: Re: Default spheres looking more like ovals?
Post by: CrashDrive on September 15, 2014, 01:03:37 am
cooldude234 I think you mean arctic caps. lol

ronaldefarmer It definitely shows up after subdivision. Even my imported sphere had a slight variation but not
as bad as the default sphere. The sphere itself is perfect though. Creating one with 48 x 24 divisions still shows perfect
and the more divisions the more accurate the subdivision. Think we just have to live with it.  :)
Title: Re: Default spheres looking more like ovals?
Post by: cooldude234 on September 15, 2014, 03:12:34 am
LOL, it was originally misspelled and spellchecker came up and I just clicked on it thinking it would correct it to arctic instead of attic :P
Title: Re: Default spheres looking more like ovals?
Post by: Kyle on September 15, 2014, 04:26:34 am
It shows up before and after subdivision, because its really about the proportions. It just becomes more apparent after subdividing because it simplifies things visually.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on September 15, 2014, 04:45:01 am
Kyle,

Here is that Blender UV Sphere again if you want it. The original wasn't centered correctly but it should be fixed now.
Title: Re: Default spheres looking more like ovals?
Post by: ENSONIQ5 on September 15, 2014, 09:02:22 am
I must be missing something, standard sphere objects are identical from all directions on my system.  Image attached is a standard sphere, front view, with a duplicate over-laid and rotated 90 degrees in the Z axis.  The outsides align perfectly.

After subdivision there can be a difference, the poles don't subdivide well.  I normally subdivide the standard dodeca-rhomacuboctrahedron (or whatever it is... looks like a soccer ball!), divides down to quads and lacks the polar distortion.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on September 15, 2014, 03:00:50 pm
ENSONIQ5, Same here, it just seems to be a problem with subdividing the sphere as far as I can tell.
Title: Re: Default spheres looking more like ovals?
Post by: Kyle on September 15, 2014, 06:59:54 pm
My bad ENSONIQ, looks like your right.
Title: Re: Default spheres looking more like ovals?
Post by: CrashDrive on September 15, 2014, 07:15:22 pm
Well...this is an interesting topic. I believe I said that in my previous post.
We are all correct in one way or another.

Sphere divisions in Anim8or I just realized are limited to 32x16, so overall dimensions
read perfect, but the surface won't be smooth.

Geodesic divisions are limited to only 6, so no luck here.

The Dodecahedron  primitive leaves an uneven surface as well, as far as I tell.

Subdivision on any of these leaves a non spherical surface.

The sphere below is visually perfectly smooth and absolutely spherical by measurements.
Unfortunately it was made using 256 x 256 divisions ( in another program) and weighs in at a
hefty 3.5 megs.


Is there a way to make a visually smooth sphere with perfect dimensions in Anim8or ?
Title: Re: Default spheres looking more like ovals?
Post by: Kyle on September 16, 2014, 01:00:42 am
I guess we could manually squash it along the Y axis until its just right. That would be annoying though.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on September 16, 2014, 04:09:29 am
I don't think you can make a perfect sphere in Anim8or presently. Here is one exported from Blender. It isn't perfect but it is very close, better than the others that I uploaded. I have attached a new plugin if anyone wants to check it out.
Title: i have found a video
Post by: TheSmoothGodMaster on October 12, 2014, 02:23:47 am
heres a video on the anim8or shapes, it covers the sphere/oval. [url]www.
[url]
Title: Re: Default spheres looking more like ovals?
Post by: CrashDrive on October 12, 2014, 03:28:24 am
Although appreciated, making basic shapes isn't what this topic is about. :)
Title: Re: Default spheres looking more like ovals?
Post by: Raxx on October 14, 2014, 06:20:31 am
Well, I know I'm a bit late, but here's a solution I made if you're working with mesh objects. It's a simple spherical deformer script, which places all points an equal distance from the midpoint of the mesh. Basically, spherizes it. There's also an attribute option called spherize_Factor, which you can set from 0.0 to 1.0 (1 being entirely spherical, and 0 being the original shape). Select the mesh shape you want to deform and run the script, and it'll turn it into a perfect sphere.

The image shows an example of it working on a subdivided sphere and cube. It'll work on any mesh, really.

Title: Re: Default spheres looking more like ovals?
Post by: cooldude234 on October 15, 2014, 06:32:50 am
Very nice script indeed, but the problem doesn't lie in the vertexes themselves (anim8or has geodesic for much more even spheres) but rather their UV coordinates and anim8ors way of generating them.
As you see in the image attached when anim8or generates the uv coordinates spherically you have issues with the 'poles' of the sphere.
I kinda wish there was a feature in anim8or to manually edit each and every individual vertices UV coordinate. It would make fixing these things by hand much easier.
Title: Re: Default spheres looking more like ovals?
Post by: ENSONIQ5 on October 15, 2014, 07:16:50 am
I kinda wish there was a feature in anim8or to manually edit each and every individual vertices UV coordinate. It would make fixing these things by hand much easier.

There is now.  In vertex edit mode, click a face (or faces) and click the UV button to individually adjust the UV mapping for the selection only.
Title: Re: Default spheres looking more like ovals?
Post by: CrashDrive on October 15, 2014, 08:23:02 am
Raxx, you have created the closest yet. There is still a minute spherical variance, (very minute) and
the poles still show slight visible creases, but you made a definite improvement. 
The heavy weight sphere I created (in Blender) has no visible creases and no spherical variation whatsoever.
The LON and LAT divisions in Anim8or are very limited, so I can't create the same sphere in Anim8or.

Anyhow, Ive managed with what we've got so far and I don't see that changing any time soon. :) 
Title: Re: Default spheres looking more like ovals?
Post by: cooldude234 on October 15, 2014, 09:09:58 am
There is now.  In vertex edit mode, click a face (or faces) and click the UV button to individually adjust the UV mapping for the selection only.
Just checked, and there isn't.
And I just realized you said faces. Obviously you misunderstood what I said :P I want to edit the UV coordinate of the INDIVIDUAL vertex and not the face (which is 3 or more vertices).
That way you could easily set the exact texture locations that you need, instead of having to guess where things are freehandedly and be stuck with only one projection type per mesh!
Title: Re: Default spheres looking more like ovals?
Post by: ENSONIQ5 on October 15, 2014, 09:22:25 am
Aha, yep, my bad cooldude234, I did indeed misunderstand.  To be honest I don't really do much UV mapping in Anim8or, I generally map everything in Lithunwrap since I use Anim8or mainly as a modeller and import everything into Carrara which tends to mess up the standard Anim8or mapping.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on October 15, 2014, 05:20:19 pm
Raxx: I can see how your Spherize script could be useful for more than just fixing imperfect spheres. Would it be possible to make this script work like Anim8or's built-in tools so that you can click a button, then adjust the Spherize attribute by dragging? This is a great script.
Title: Re: Default spheres looking more like ovals?
Post by: Raxx on October 15, 2014, 08:10:13 pm
cooldude234, there's always my super awesome UVTools (http://www.anim8or.com/smf/index.php/topic,4809.0.html) scripts :P Anyway, I was addressing the OP issue of non-uniform sphere geometry.

I thought maybe it'd be nice if one could subdivide a cube, adjust it to be perfectly spherical (using my script), and use a cube map for texturing the sphere. I gave it a shot, but there's UV distortion at the edges since the faces aren't all identical in size and shape, and seams :(


ronaldefarmer, can you share that icosphere you posted, but as a .obj so that I can check out its UVs? I might write an icosphere script of my own with unlimited divisions, but only if I can get a logical UV pattern for it. As for the spherize script, I was considering that, and since you're requesting it, I guess I'll make it ;) Expect something posted in the scripts board in the near future.
Title: Re: Default spheres looking more like ovals?
Post by: ronaldefarmer on October 15, 2014, 11:33:57 pm
Raxx: Here is that icosphere, and also a quadsphere in case you are interested.

About your spherize script, What if the spherize attribute could have a negative value. I used the script to "fatten" a cube (so that the sides were convex) using values less than one, and I am wondering if it might be possible for the attribute to have negative values so that the sides would be concave.
Title: Re: Default spheres looking more like ovals?
Post by: CrashDrive on October 16, 2014, 03:54:07 am
I never realized the default sphere had creases at the poles after subdivision.

Been playing around with the Spherize script a bit more.
Started with a cube and subdivided> mesh> Spherize (twice) and got a perfect sphere and no visible creases.
The script really works nice.

Title: Re: Default spheres looking more like ovals?
Post by: cooldude234 on October 16, 2014, 05:22:38 am
Raxx I really like your Cube mapping method. It looks much better than anim8or's default spherical mapping.
I might look into this some more and make a simple standalone tool in C++ to fix this problem for now at least.
Title: Re: Default spheres looking more like ovals?
Post by: Kyle on October 19, 2014, 11:40:56 pm
Sounds like a nice script Raxx. I cant seem to get it to work for some reason though. I load the script, even restarted anim8or, select a mesh hit sphereize but see no effect.  Tried it after a subdivision as well.
Title: Re: Default spheres looking more like ovals?
Post by: Raxx on October 20, 2014, 01:14:06 am
Hi Kyle, are there any errors in the console window? Also, it doesn't work on subdivision meshes themselves, as of yet. I'm almost done with the advanced spherize script and will have it posted shortly.

[update] Posted in the ASL Scripts board.
Title: Re: Default spheres looking more like ovals?
Post by: Kyle on October 20, 2014, 06:29:54 am
Think I got it. I guess I wasn't subdividing before hand. Seems promising. Looking forward to any improvements. Keep it up!