How to Make A Perfect Low Polygon Sphere

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Old 01 January 2013   #1
How to Make A Perfect Low Polygon Sphere

Can someone please assist me here? Examine the following picture I made:



As you can see NONE of the methods are perfectly round at a low resolution. And yes, it has to be a polygon. The Dodecahedron and Icosahedron might appear to be round, but they actually have slight dents and imperfections in them that are quite noticeable.

PS: this is a slight repost, but I realised this is a more general issue so I properly posted it here.
 
Old 01 January 2013   #2
To get a perfect sphere in max you just create a default sphere with a ton of segments, it's kind of odd that Maya doesn't have one. I suppose you could create one with nurbs and convert it to polygons.

You could also create a circle shape (or line object) and break half of it off, then use some kind of lathe modifier to create a sphere.
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Last edited by Psyk0 : 01 January 2013 at 04:36 PM.
 
Old 01 January 2013   #3
That's the thing though, I don't want it to have "a ton of segments", it must be low poly. And even if you increase the number of segments, it still is not round, but oval instead.

Edit: Just tried creating a nurbs sphere and converting it to polygon, the result is not bad, just that the polygon then has 216 faces and has those triangles at the top and bottom where the points meet.

Last edited by Broodstar : 01 January 2013 at 04:39 PM.
 
Old 01 January 2013   #4
Define low poly? how many polygons?, usually in a game engine you can get away with geospheres, an octa geosphere made out of 7 segments will end up at 392 triangles.

In case you missed my earlier edit.
You could also create a circle shape (or line object) and break half of it off, then use some kind of lathe modifier to create a sphere, collapse to polygon and done.
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Old 01 January 2013   #5
Well I want them to be as low poly as the objects in the picture I posted, which are all under 60 faces.

I can't believe this has not been asked more frequently, I mean I found 2 or 3 posts on the internet about people asking similar question to what I am asking, but how do people make planets? Marbles? Molecular structures? Yes they can be very high poly, but like I mentioned, even the high poly objects where not perfectly round, except the nurbs conversion to polygon.
 
Old 01 January 2013   #6
Hey man,

Computers cant display a perfect sphere like in the real world. If you want it to look smoother, you'll have to add more resolution untill it appears smooth to the human eye.

-AJ
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Old 01 January 2013   #7
I just want to know how you guys/industry professionals make their low poly spheres
 
Old 01 January 2013   #8
They use normal maps to fake the smoothing. You can still tell they're not perfect spheres by looking at the silhouette, though.
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Old 01 January 2013   #9
I think Meloncov has hit the nail on the head. From your images, it looks like the surface normals of the polygons that make up your low-poly spheres are not being interpolated properly.

If you take a very low poly object and increase the poly count with subdivisions, the tool won't really know that you are trying to make a sphere, it will simply guess at what the vertex normals should be, given the starting polygons. If the starting polygons are "flat" - ie. all the vertex normals of a given polygon are the same - then you will get a very poor result.

Even if your vertex normals are shared, and are taken from the sphere surface at that point on the sphere, if you have too few polygons, you will still get interpolation slope discontinuities along polygon edges. You simply can't avoid that - unless, as Meloncov suggests, you map a normal map onto the polygons that overrides the normal interpolation.

Does that help?
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Old 01 January 2013   #10
in maya use sub-d or nurb surface for smooth sphere that renders fast.
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Old 01 January 2013   #11
Hey,

There is a script on highend3d (creative crash - I think it's called now ) that allows maya to create geospheres. This is what you need. I use it daily. Just search on there in the maya scripts section for geospheres. Or add more resolution to the default quad sphere poly primitive. That's what most people I know do. You need to have more divisions in one axis than the other tho. Just play about until the largest poly's look almost square. Obviously number of divisions overall is relevant to how much screen space the object will occupy in game

Geospheres will give you a good triangulated sphere for less faces than a quad sphere (don't forget each quad = 2 triangles / faces) but 60 poly's (or tri's) just isn't enough for a decent sphere. Tho possibly passable ingame.
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Last edited by rob-beddall : 01 January 2013 at 01:35 AM.
 
Old 02 February 2013   #12
spheres in games are usually either sprites or a smoothed box with a good normal map
 
Old 02 February 2013   #13
In 3ds max, you can create a low-poly sphere out of a box by increasing the segments and adding a spherify modifier. Once you smooth it out it'll look good, be all quads, and low-poly. Just increase the poly count depending on how round you need it to be appear.
 
Old 08 August 2013   #14
if you want to remove slight dents then use soften edge (normal > soften edge) it will smooth your mesh without increasing any more edges.
 
Old 08 August 2013   #15
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