Using half the UV space

Incomitatum

I figure before you can walk, you should crawl; hell, I have been trying to run...

So I am working on some game design, and also want to use low poly assets. I notice most of these use 32, 64, or 128 pixels and use them well.

I want to learn to use the most of what little I am given. On my character's face I can use a 64x128, but I am not sure how. I have laid out my UVs on the bottom half of the space, but I am not sure where to go from there?

Do I just export it and cut the thing in half in photoshop, and then scale the V down to 0.5 in Max (on the model); I mean I am sure that will work, but is it the -right- way to go about that?

All help is appreciated.

-Andrew

SHEPEIRO

pictures will help so-much

Incomitatum

I am talking about using a 64x128 rather than a 128x128; just asking how this is normally done.

SHEPEIRO

sorry i guess so but with out a pic of your original Uvs its hard to tell, come on were artists we work in pictures ;-)

EarthQuake

I think the answer to your question is this: unwrap to the side you want to use, only that half, and then stretch those uvs by 200%, now when you apply a 1:2 texture to it, it will show up correctly.

Incomitatum

Yeah I have it with a Tiling of U.1 V.2, and and offset of U.0 and V.0.25; works fine. I was just wondering if this is the -right- way to do it. I guess it is. Whatever works.

Eric Chadwick

Max does let you set the aspect ratio in the Unwrap editor (options), you could try that. It does make things a little weird though, when you rotate something it squishes/stretches as it goes around. But it might be easier for you.

MoP

Max doesn't actually squish it as you rotate if you set the custom aspect ratio, Eric. I work in this way all the time, with textures like 2048x256. Rotate/scale/everything is fine.

The broken way is what Maya does

Eric Chadwick

Ah, misinformed I am. Thanks MoP.

Mark Dygert

The warping and stretching Eric talks about normally happens in older versions of Max when the a material with the correct dimensions hasn't been assigned. The other cause is the transforms have been heavily screwed with and need to be reset. Reset Xform normally takes care of it. The last time I hit that issue was max8...

Eric Chadwick

Heh, my last employer only wanted to use square textures, so I haven't used rects since oh maybe max 5. I should qualify my assumptions a bit more.

Incomitatum

Well, in Max, this has all worked fine. I use the bottom half of the sheets on things like heads and hats which are unwrapped using cylindrical mapping. Doing this means I only need to affect the V: it has an offset of 0.25 and tiling of 2.0 in my material editor.

This has come to bite my programmer in the ass. We are using XNA and exporting our models out as FBX using ASCII so he can modify the texture paths. Thing is, on the texture that are 2:1, the engine scales them UP so that they are square, and thus we get smearing/stretching.

I am a good conceptual programmer. But not familiar with the framework for XNA.

I suppose we need to have it run a check to see if the texture is square or not, and if not then tile by 2 and offset by 0.25, like in my material editor.

If I consistently use the -same- half of the texture sheet, this should be fine. Right?

If any of you have experience with this, your wisdom is greatly needed/appreciated.

Thank you for your continued input,

-Andrew

Joshua Stubbles

Err, I have no idea how XNA works, but it sounds wonky. We use rectangular textures on the 360, so I don't know why XNA wouldn't allow it. I've never used the offset feature in the material editor though - I just move the UV's to offset stuff. Remember, you don't have to stay inside the 0,1 UV box.

Incomitatum

Off Topic:

Remember, you don't have to stay inside the 0,1 UV box.

Wha??? Really?? Since when? I mean, hell, I will take your word for it, but I thought the only time things were allowed to go -out- was when you were offsetting so that things would tile correctly.

So, since you -can- go out, though there is not benefit in my current scenario, what are some of the advantages to doing this?

On Topic:

Yeah, really I am an artist trolling for techical details and progamming notes to hand off to my programmer. Everything is hand made in XNA but there are a few modules that can help make life easier; loads of tutorials too.

Eric Chadwick

Don't setup UV offsets in the Material Editor, most exporters don't read that data, they only read what's in the mesh UVs (what you can edit via the modifier stack). This is probably why your textures are looking stretched in-game, but not in Max. A quick way to fix this is to reset the material, and use the UVW Xform modifier instead, since it actually affects the UVs. Hope that makes sense.

Incomitatum

@ EricChadwick

THAT did the trick... thank you very much; never knew that modifier existed.

Richard Kain

The correct answer, of course, is to use Blender.

In Blender when you choose a texture in the UV face editing window, your UV workspace automatically scales to the dimensions of that image. So if your image is 1:2, all the UVs you were setting up will automatically scale to that aspect ratio. And if you select your texture before you start your unwrapping, you can work with that aspect ratio from the word go. And if you don't feel like cooking up the texture ahead of time, Blender has the option of generating a texture for you that is good for testing.

Michael Knubben

What's Blender, Richard? Is it some sort of plugin that he can use in his 3d application of choice: 3d studio Max?

Do tell us more about it, maybe we'll all want to use it, eh?
Also: let Jesus into your life, Richard.

System

Holy Mary mother of... heh you crack me up MightyPea:poly140: yeh but, no but, what is Blender?

Mark Dygert

Richard Kain wrote: »

The correct answer, of course, is to use Blender.

In Blender when you choose a texture in the UV face editing window, your UV workspace automatically scales to the dimensions of that image. So if your image is 1:2, all the UVs you were setting up will automatically scale to that aspect ratio. And if you select your texture before you start your unwrapping, you can work with that aspect ratio from the word go. And if you don't feel like cooking up the texture ahead of time, Blender has the option of generating a texture for you that is good for testing.

The funny thing is so does 3dsmax. In fact you can even set up your UV area without ever applying a texture.
I think the underlying message I'm sending here is, know both tools before making a comparison. If you don't you're just taking your dancing pony to the dog show.