Where to learn about UVmapping?

[konraden]

I have yet to find any good tutorials on more advanced uv creation. All I can find is walkthroughs of the different types of unwrapping and tutorials on how to unwrap a characters.
Sure they are useful if you are completely new to unwrapping but when you are not they have outlived their usefulness.

Can anyone point me in the right direction if I want a good lesson in making good optimized UV´s for games for a wide variety of objects(especially not characters)?
What should I think about, what are "nono" and what are "yesyes".
Right now I am just trying to figure things out myself and usually that only gets one so far .
I am interested in UVmapping for both low and highpoly. Thou low poly I can go trough the World of warcraft files and look how they have done.

/Joakim

[joukejan]

Well learning yourself is one of the best methodes I think. Though there are some tutorials online that can help you through this proces. Eat3D and Gnomonology have some good tutorials on this.

Unwrapping a model can never be done the same way twice. You'll always end up with an other layout.
I do have a couple of things I take with me when unwrapping, they are not neccesarely nono's or yesyes's but they give you an impression of what to consider.

For unique/key models I would prefer not to have overlapping UV's. But for less important models or repertition in the model you can easily use overlapping UV's. But you should always be carefull with overlapping UV's. Don't have overlapping UV's before you are baking a normal map. This will screw the baking up.
Also keep in mind you can use multiple UV sets. In some cases you would want this to do.
Another thing to think of is the proportions/scale. I often use a bigger scale for the parts of the model that is more seen and has more imortance. For example weapons in first person view. Everything in front of the camera should have a bit more detail then way ahead of the camera. In some cases there is a slight blur over whats very close to the camera. So in that case those parts can have less detail and the middle part of the weapon can have some more.
These are some of the considerations you can take in uv mapping your models. But as I said learning yourself is a very good methode, you will come across much errors which you will have to fix and this will give you the opportunity to learn and to get insight on how to best unwrap your models.

Hope this helped!

[Benjammin]

UVing is one of those things thats best learnt through trial and error. Once you understand the basic ideas, the rest is just practice and refinement.
I think your best option is to model something with shapes that you think will be a challenge and work through the process. Its also much easier to get feedback and tips on a forum when there's something for us to point to.
A couple of general tips to follow on from Joukejan's:
1) Seams are ugly. You want to try and have them in areas of the model where there would be a natural seam (spaces between metal plates/planks for example) or in an area of the model thats unlikely to be seen and/or is in shadow.
2) Try and use up as much of your texture space as possible. This needs to be balanced with other considerations such as seams and distortion, but remember that empty texture space is wasted memory for the game engine.