Help! Art test :)

The_Kozmonaut

So I am about to start an art test and I have a couple of questions.

1. How do you make a rectangle UV map? (256x512)

and the second I will quote the doc they sent with the test:

"The alpha channel of the normal map texture should be used for specularity."

What does that mean? I have honestly never heard of that before.
Every time I have an art test I get hung up on the technical stuffs

ImSlightlyBored

for 2, save your normals as an rgba doc (tga does this,not sure what others do or what they want off you) and in ps's channels, put your grayscale spec (power) map and seperate in-engine.

rooster

1: what program? (I'm assuming you mean make your uv window match the dimensions?)
2: in your normal map image create an alpha channel ( in the channels tab in photoshop) and put your specular map into the alpha

Joseph Silverman

Make your specular like normal, but greyscale only. Instead of including it seperately, save it in the Alpha channel (photoshop channels tab, create new, paste it in, make sure to save as a TGA or something with alphas) of your normal map.

Rectangle UVs are easy. Just lay out your uvs twice as wide (so over two boxes in the grid, if you're a max user) and scale down by 1:2 horizontally before you bake out into a 256x512.

stimpack

There is an option in the uvw editor to set the size ratio. Just type in the size you need and lay out your uv's. Then when you bake be sure to type in the dimensions. ez as that.

The_Kozmonaut

thanks everybody. I believe they use max so I am using max 2009 on this project.

The_Kozmonaut

I do have one more question about tileable textures. Any good tutorials or can anyone explain how it is done. I know how to make a tileable texture using offset and all that in photoshop. I mean how is it used practically in games?

Justin Meisse

If you're used to doing characters, you probably haven't moved your UV's outside of the 0-1 box in the UV editor, give it a shot, you'll see that the texture tiles outside the box.

In the UV bitmap options put a check on "Tile Bitmap" and adjust how many times you want it to tile to see it tiling in your edit UVWs window, that doesn't have any effect on how the texture tiles it's just so you can see it tile when you are moving around the UVs.

The_Kozmonaut

"Model the tree in under 2000 Polygons, using two 1024X1024 tiling textures (one color map and one normal map) for the bark"

So does this mean I dont make a high poly version and bake the normals? Do I just use crazy bump to create the normals? I am really confused about tiling....

Tumerboy

you can bake geo down to a normal map, that's no problem. Just in this case, make sure your GEO is tileable and it should work fine. I'd double check the map it generates.

The_Kozmonaut

Well this is still not sinking in. This will be my first time tiling anything and I dont quite get it. I think my main question is how do you lay out UV's for a tiling texture? Are there any tutorials around about tiling? need some serious help here

Sage

try and think of it as a straight line. You get a cylinder or cube and you make it seamless the uvs seamless. Then you scale it up so it tiles. So you want to keep your uvs as straight as possible especially at the seams so the pixels can line up. How would you texture the barrel of a gun or any long object. To get the most out of it you are going to spilt the object into chunks so that you can line up uv islands and take up less of the texture sheet. In this case, if you have to use one texture that tiles for an entire object you have to do the same except you get a square to do it with.

A tree is sort of like a long cylinder that has a taper modifier and is following a path deform, with probably a twist here and there. The you might be able to get around the uv issue using a loft for the the main trunk and several lofts for each of the branches. Might save time.

Meh I hope that helps and doesn't confuse you more.

Alex

The_Kozmonaut

okay so this is the tree I am working on. I dont understand how I make a tileable normal map out of this tree.

oobersli

i'm pretty sure it means.... make a generic bark texture you can tile in all directions for the bark. The normal map is just to get the bark to pop out more but not to actually form the individual details of the tree.

So pretty much just build your low poly tree and tile the bark texture all about it. I could be wrong, but thats just my take on the info you've given us.

Tumerboy

oobersli wrote: »

i'm pretty sure it means.... make a generic bark texture you can tile in all directions for the bark. The normal map is just to get the bark to pop out more but not to actually form the individual details of the tree.

So pretty much just build your low poly tree and tile the bark texture all about it. I could be wrong, but thats just my take on the info you've given us.

QFT

This is what they are asking for. A low poly tree, with a simple, tiling texture applied to it. Making a z-brush/mudbox model and going nuts on the details of a high res model, is not going to help you in this situation.

Either way, no offense, but you are probably not ready for the position you applied for if you don't even understand the basics of tiling textures.

The_Kozmonaut

well the tree in zbrush took about 30 mins so it is no problem to scrap it. I read a mini tutorial at chrisholden.net and i think i get the idea. I was just thinking you had to stay in the 0 to 1 space of the UVs

Eric Chadwick

Some tips here, must be the same art test.
http://boards.polycount.net/showthread.php?t=55188

The_Kozmonaut

yea looks like it is the same. Thanks a lot