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UV Mapping

Hey
I was wondering if any of you Could help me. I have always had problems with uv mapping and texturing in general.

The main problem is I dont totally understand it Even after tutorials I still cannot grasp it completely So I was wondering if any of you could advice me on it.

See I get the bit where its basically like a Jigsaw but I am not completely sure What needs to be stitched together Etc so if any of you could help me It would be greatly appreciated.

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  • Joshua Stubbles
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    Joshua Stubbles polycounter lvl 19
    This does a good breakdown of what UV mapping is. It was linked to on the Polycount Wiki. Please check out the wiki, it's got oodles of info.

    http://waylon-art.com/uvw_tutorial/uvwtut_01.html
  • Eric Chadwick
  • Mr. Bean
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    Hi Greenbullet,

    I like to think of a texture as a lot like a map of the world: a model, like the Earth, is three dimensional, but a map (or in this case a texture map) is flat and 2d. When the model is flattened into a texture, the only way to be able to see all of it at once and not have parts hidden underneath others is to break it into parts. When you break it into parts, seams are created because the texture is no longer continuous (a map of the Earth has a seam because the map "stops" on the right and left edge, instead of continuing all the way around like a globe. If you rolled a paper up into a cylinder and wrote a sentence that goes all the way around the paper, when you unroll the paper the sentence would be cut off at the right and left edges.). Unwrapping is just the process of creating the UV layout--the "map"--which we can paint or place the texture over.

    You'll want to unwrap the model so that the seams are located strategically. You should try to have seams hidden where they're difficult or impossible to see. I don't think there's a universal rule you can follow when it comes to stitching parts together...One of the biggest keys is to avoid stretching in the texture, so sometimes it's impossible to stitch parts together without getting really ugly stretching. I guess I'd say that it's best to stitch together UVs when you can, because it gets rid of seams and can make texturing a little easier, but only when they're from the same part of the model (if you're unwrapping a character, you don't want to stitch parts of the hand to parts of the face). If you're using 3ds Max, when you select UVs in the Edit UVWs window, edges on other UVs that can be automatically stitched to edges from the UVs you have selected show up blue. Just because you can stitch doesn't mean you should, though. There are also instances when it doesn't matter as much if there are seams, so it's alright not to stitch parts. An example of this would be when the texture will be metal, so there will be edges or highlights painted over where the seams are.

    It's a good idea to have a checker texture applied to your model while unwrapping so you can tell if there's stretching, or if parts need to be scaled, mirrored or rotated. Another tip is to scale UV "clusters" (clusters, shells, islands, etc. are just nicknames for groups of UVs) up when that part in the texture will have a lot of detail, and make them smaller if they won't be seen well or at all. You have to pack UVs very tightly together, so it's important to save space when you can. When UVs are identical you can place them on top of each other to save space. You can mirror UVs if necessary to be able to make them fit on top of other UVs that are identical but mirrored, but keep in mind that mirroring a UV from its normal position will also mirror the texture you put over that part.

    You might want to wait until you're more comfortable with unwrapping before you try some of the techniques I talked about in that last paragraph. This stuff is confusing enough without worrying about scaling and mirroring UVs, so make sure you get the hang of basic unwrapping before you start experimenting with those things.

    If you haven't already, you might want to take a look at Racer445's AK video tutorial. There are parts to the tutorial that show how he unwraps and textures. I also recommend you take a look at this tutorial.

    I hope all that helps you. Unwrapping isn't easy, and it can be a little tedious, so be patient with yourself and keep practicing!

    PS: To give credit where it's due, I would like to make it clear that I've learned just about all of the above from tutorials and other artists who have been kind enough to share tips and advice.
  • warby
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    warby polycounter lvl 18
    a uvmap doesnt necesarily have to have that jigsaw puzzle layout most effcient environment assets have lots and lots of crazy overlapping uvs reusing/sharing pixels when ever possible.
  • littleclaude
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    littleclaude quad damage
    Forgive me for bringing this thread back to life but I thought you might like to see this.

    UV mapping in Maya in a few clicks with the new unfold 3D option.

    And for UV packing - http://www.polycount.com/forum/showthread.php?t=145328

    Untitled_1.jpg

    Untitled_2.jpg
  • StriderAnimus
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    Hello Polycount. I'm kind of new at Maya and 3d modeling in general and I have a question about UV mapping that I can't seem to find the answer to anywhere or at least that I can understand. I'm working on a Mech that's bassed on a tutorial site online and
    I've arrived at a wall I'm really stuck. When I try to unfold my UV's after I've selected the edges I want to cut, I shown what is basically a straight line or if you will a profile view of a flat 2d image. I would like to see it from a front point of view in my UV texture editor panel. Thanks for any help it means a lot I'm going crazy!
  • Eric Chadwick
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    StriderAnimus, a screenshot would help.
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