UV Mapping

[Sheekel]

What is it? (uv mapping)

[jcnossen]

Strictly speaking UV mapping is mapping of 3D space to texture space, through the use of texture coordinates. A lot of people will now want to say that it's mapping of texture space to 3D, but that is the texture mapping part, not the UV mapping. Ok I'll stop nitpicking now

Explanation:

You have a set of polygons that are defined by 3D points (vertices). These 3D points are defined by X,Y and Z coordinates. This is as far as OTA goes. With UV mapping, you add to these vertices UV coordinates, which define to which location on the texture map, the 3D point corresponds.
U is the horizontal coordinate on the texture, V is the vertical.

Look at my wonderful ascii art

Code: Select all

(U=0,V=0)------------(U=1,V=0)
|                            |
|                            |
|                            |
|     Texture image          |
|                            |
|                            |
(U=0,V=1)------------(U=1,V=1)

What happens with 3DO models, is that each polygon vertex automatically gets assigned a texture coordinate at one of the image corners, this is also why it didn't allow more than 4 vertex polygons, because a texture only has 4 corners
But with s3o, you can specify how the texture is mapped to the model.

Code: Select all

(U=0,V=0)------------(U=1,V=0) 
|                            | 
| U=0.2,V=0.3                | 
|     _______U=0.5           | 
|    /       \               | 
|   /          \             | 
|  /_____________\           | 
| U=0.1,V=0.7    U=0.6       | 
|                            | 
(U=0,V=1)------------(U=1,V=1) 

I'm not sure if that clears up a lot, but just search for some tutorials, texture mapping is a really common game technique.

I found another UV mapping application: http://www.uvmapper.com/downloads.html

[[K.B.] Napalm Cobra]

Wings has it built in.

Instructions...
Create uv map.
Export piece to obj.
Edit image file.
Import back in.

[Caydr]

In other words, Wings does everything, and anyone who still uses Rhino should go straight to hell.

[jcnossen]

There is a whole bunch of different ways to do it, imho Ultimate Unwrap has really good auto-unwrapping tools, and other editors might have a lot less fancy stuff. So wings might just suck on this as well....

[Caydr]

Wellllll... I can't say for sure, but wings does appear to work pretty well after a little experimentation. I tried ultimate unwrap as you suggested, but can't get to first base with my imported model.

[smoth]

google.

[SwiftSpear]

Any good modeller will build thier own UV maps. The automated ones are hell to texture, you acctually save alot of time building the UV properly so that you aren't going "WTF does that tryangle on the UV map do? It's in the middle of nowhere!"