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Unwrapping a Sphere?

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TorQue[MoD] polycounter lvl 16
Hey all!

So I'm working on a model of the solar system and obviously have a lot of spheres that I need to unwrap. I didn't think this would be an issue when I started but now I'm finding that unwrapping a sphere without major seams or distortion is a lot harder than one would think and there really aren't any useful tutorials on the subject that I've been able to find.

Does anyone have any tips on how to do this properly in 3D Studio max? I would think pelt mapping a sphere would be an easy way to do it, but I can't seem to loose the distortion in the center area of the sphere.

Any help on this would be greatly appreciated.

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  • DarthNater
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    DarthNater polycounter lvl 10
    I usually cut my sphere in half along the middle loop and then make a 'half loop' cut from pole to pole. You have to be real good at hiding your seams, but it creates less distortion. I do things the hard way though so I'm sure someone (Vig) will come along and make me look like an ass...
  • Mark Dygert
    Quadsphere maybe?

    Start off with a box, unwrap it.
    Turbosmooth it once or twice until its a smooth sphere, might need to relax it.
    Assign all the faces to one smoothing group and you're good to go.
    Now you have a nice sphere made of all quads unwrapped in a predictable way.

    There's a quad sphere primitive shape plug-in for max, probably something for Maya too, otherwise you could just as quickly make it.

    Ha ha ha Darth you crack me up, thats a good method too, could probably easily apply it to a quadsphere too, instead of going with a box map?
  • Grobi
    I remember this image cropping up in a thread a while back;

    293diyf.jpg

    Basically, to make a quad sphere thats easier to unwrap than a regular sphere primitive you should start off with a cube, add a couple of segments to each axis and apply a spherify modifier, you'll be able to follow the example's here pretty easily after that.
  • DarthNater
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    DarthNater polycounter lvl 10
    Yeah your method sounds easier. Never thought of starting with a cube. That's why I don't have a game job yet HA

    Anyway, here's a screenie of how I do it. I'm pretty good at making seams disappear with Photoshop (I'd say I'm more skilled in PS than I am at unwrapping) so you have to play off your strengths. Try Vig's method first, it makes a lot more sense HA.

    Untitled-2.jpg
  • TorQue[MoD]
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    TorQue[MoD] polycounter lvl 16
    Thanks guys for responding so fast!

    Vig, I tried your idea of using a box and then just Msmoothing it a few times to turn it into a sphere but the problem there is it ends up at about 768 polys by the time it looks nicely spherical.

    I was talking to Kman and he pointed out that using a Geosphere with Octa for the Geodesic base type is a much better way to go about it and also makes the poly count much lower. He unwrapped a sphere for me and showed me how he laid it out which was quite good, however after playing around on my own for a bit, I realized that if I simply create a geosphere and load an unwrap onto it, Max unwraps the mesh perfectly without my help at all.
    mars_render.jpg

    It does have a bit of a seam at the top, but with a little work in photoshop, I could make it completely invisible. The only problem now is if I want to add some snowy areas to the poles, I'd need to re-unwrap the top and bottom and it might make a more obvious seam.

    Still, not bad for virtually no work. If anyone else has to do something similar, I definitely suggest using Octa Geospheres.
  • Piflik
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    Piflik polycounter lvl 8
    For Snow Caps you can use simple Maps...one projecting planar from he top for the actuat texture, and one projecting cylindrical from the sides for a Mask...at least thats what I'd do...if you want, you can then bake it into on texture, using the original Unwrap...
  • TorQue[MoD]
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    TorQue[MoD] polycounter lvl 16
    Thanks Piflik, I'll see about doing that!

    BTW, what size of a monitor do you work with? I've got a 40" tv hooked up to my computer with a 1920x1080 resolution and your website requires me to scroll to the right just to see the entire thing. You might want to scale it down just a smidgen :P

    Your models look pretty good otherwise :)
  • Piflik
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    Piflik polycounter lvl 8
    Strange...it should always fill the complete width of the monitor...I used only relative width values...
  • Mark Dygert
    That kicks ass.

    /saved
  • TorQue[MoD]
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    TorQue[MoD] polycounter lvl 16
    Vig? The fact that geospheres are automatically unwrapped? Are you kidding me? Is this the first time in polycount history that someone else told Vig how to do something? lol

    I thought you were the grand champion of max? Quick, brush it off like it was a freudian slip and you already knew how it worked!
  • vahl
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    vahl polycounter lvl 14
    hey Peter !!!! how are you doing these days man ??? been so long :p

    (end of thread derailment :p)

    I'd go the geosphere route too, that or the sphere, but with a spherify kind of modifier on top to make it round without using too many polies :)
  • Mark Dygert
    Heh I get schooled all the time, won't be the last time =P
    Always learn something new.

    Now that you mention it, I remember it coming up in a previous "how do you unwrap a sphere" thread about a year ago. I think Mojokey brought up the geosphere? Because about that time I convinced our modelers to start using them for the eyes in our models (creepy wire views look like teeth). It saved enough polys we could do proper forehead wrinkles.

    I personally don't use them that much in stuff I make, as I hardly ever need just a sphere and I need something with clean straight edges that I can use to build other things with. The quadsphere is pretty good at that. It also ports over to a sculpting app a lot better than a geosphere or a regular sphere with poles.
  • TorQue[MoD]
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    TorQue[MoD] polycounter lvl 16
    Hey Vahl! I'm great bud how are you doing? I've been keeping an eye on your portfolio and polycount postings, you've got some absolutely amazing stuff in there!

    I'm actually starting up a new project now that I met a useful programmer! Its a very small turn based space game actually hence the need for figuring out how to unwrap spheres :P

    Brutal as I'm sure you've figured out has been put on indefinite hold until it gets the proper funding it deserves!

    Vig, I don't believe you get schooled all the time, but I'm sure it happens occasionally. And see, what'd I tell you? It was a freudian slip of sorts... you just forgot that you knew the answer already :)

    Yeah they do look hella freaky in wire form, but hey, they work so what do I care? Lower poly too so that's always a bonus.
  • Scizz
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    Scizz polycounter lvl 10
    Grobi wrote: »
    I remember this image cropping up in a thread a while back;

    293diyf.jpg

    Basically, to make a quad sphere thats easier to unwrap than a regular sphere primitive you should start off with a cube, add a couple of segments to each axis and apply a spherify modifier, you'll be able to follow the example's here pretty easily after that.

    The last picture. How do you get the sphere to unwrap like that? I normally use quad spheres but for doing a prop like a globe, I think unwrapping it this way would be more beneficial.
  • Eric Chadwick
    Select those edges on the model, then do a Pelt relax.
  • Scizz
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    Scizz polycounter lvl 10
    OMG Thank you! Your a life saver.
  • JoshexDirad
    Hi, this will be my first post here if lag doesn't kill it. seriously theres a delay while typing. notepad copy pasta time.

    I too have been studying this, for exactly the same reasons.

    first off, I am a blender guy, so this help may need to be translated into Maxese.

    I just posted how to do this, here:
    https://blenderartists.org/t/spherical-unwraps/685424/2

    If you don't want to go there, another user posted a method thats almost perfect, but leaves gaps at the poles by turning a plane into a sphere and not merging the square faces near the poles into triangles thus allowing you to make a simple cylinder map to it.

    While that method is decent, it presents a problem, you can never ever merge the vertecies at the poles! otherwise you lose the extra edges which give you square UV faces to fill-in the texture space. If you merged them you’d suddenly be missing some texture space coverage and would see very obvious seams.

    However, not merging them will create surface normal inconsistency at the poles (dark spots). (keep in mind blender renders unmerged non-parallel edges as separate surfaces so reflections and shadows will not float over them properly.)

    But there is another way to get a perfect spherical map on a normal UV sphere. It CAN use 100% texture space as well. but it cannot handle generated textures NATIVELY, and will take some extra mapping steps.

    You probably never thought of mapping it corner to corner. that is to say you put the poles at any 2 diagonally opposite corners of the texture space and fill in the rest. It’ll take extra work to make the UV layout, but it’s worth it in the end. Just make sure you unwrap a blank sphere first then make copies with new duplicate materials for each object that way you don’t have to redo the UV layout each time…

    Technically you could use ANY good UV layout you want and get a seamless mapped sphere. It just takes extra steps in the mapping process, so if you don’t like the poles at the corners method, you can follow the following steps with your layout. (hint it will work for just about any shape even an Icosphere!)

    Step 1: make your UV layout how you think it will be best for your sphere. or how it NEEDS TO BE for your project’s aims.

    Step 2: For blender’s built-in generated textures (if using some other square or rectangle texture, ignore this step)

        on your sphere make any layers you need and any generated textures you want to apply, get them adjusted so they look good.
        on a UV unwrapped plane, load the sphere’s material(for a copy of the textures), then bake the generated textures to an image one layer at a time, save them each with easily findable names.

    Step 3: Make a new plane, subdivide it so it has the same number of faces as your sphere but for now maintain a rectangle or square outline.

    Step 4: Unwrap the plane to fill the texture bounds and load your intended sphere textures.

    Step 5: Modify the plane in Edit mode (you might want to open 2 copies of blender, so you can see your sphere’s UV outline while doing this) and adjust the faces of the plane to EXACTLY match the proportions etc. of the UV layout of the sphere!

    Step 6: put a camera above it angled down. set the render settings to not render the background, but instead render alpha. Change the output image format to a format that supports alpha (TGA, PNG, GIF) and switch the texture color settings to RGBA, Change the image proportions to match the proportions of your intended sphere images size on X and Y. adjust the camera height until the plane occupies the entire render area exactly (or until it will exactly match the Sphere’s UV layout (you see what I’m doing here?)).

    Step 7: back on the plane, set it to shadeless, render it 1 texture layer at a time and save each image as an easily understandable name. (I use NOR at the end of a normal map COL at the end of a Color map etc., I.E. Water128x128NOR.tga, Water128x128COL.tga)

    Step 8: on your sphere, import the images you just rendered as textures on your sphere, the UV layout should match exactly and you should not have any visible creases.

    Benefit: No bad normals at the poles, no gaps, blender sees the whole sphere as 1 surface so reflections and shadows flow over the whole sphere properly, everything is merged you don’t have to worry about accidental “select all”+“remove doubles” episodes. Complete coverage. Full control of the UV layout.

    This method is untested. It makes sense logically. I cannot guarantee generated textures will repeat correctly after being saved to an image, that may take some manual adjustment in The GIMP. (copy a small amount of the edges of the image to another layer or image, then delete 1 opposite side of each on X and Y from the original image, paste the opposite side’s pixels there, blend/smudge into place to remove any hard pixel edges.)

    I will be testing this at some point.

  • sacboi
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    sacboi polycount lvl 666
    Hasn't Blender 2.8 / 2.9xx an extra objects preset mesh library/plugin which includes a quad sphere primitive!?

    Should take all of 5mins, if that! too manually unwrap in a predictable way as Mark Dygert commented 11 years ago upthread for Max.

    Or just simply subdivide a cube, without the hassle of dealing with poles.
  • JoshexDirad
    sacboi said:
    Hasn't Blender 2.8 / 2.9xx an extra objects preset mesh library/plugin which includes a quad sphere primitive!?

    Should take all of 5mins, if that! too manually unwrap in a predictable way as Mark Dygert commented 11 years ago upthread for Max.

    Or just simply subdivide a cube, without the hassle of dealing with poles.


    exactly, but, the point of my comment was not the shape, but method to generate and apply the texture to any UV map in a way that has no creases regardless the shape.


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