never thought about it

I have never payed atention to this.I am sure it is simple but...

I wanna know why is important the direction of a surface normals when it comes to lighting.Don't get me wrong.I know why is important for modeling but for lighting???

I'm not a Maya user, but I guess normals are important part of lighting calculation...

I think light ray emitted from light source hits objects surface, and is reflected in direction calculated by surface normal.

But I may be wrong.

why is it important for modeling ??

it is important for light calculation, as empeck said. Calculating angles between light rays and normals helps alot and simplyfy the process of rendering

In maya you can not combine objects with diferent normals direction...

surface normals always have to point out...but there are cases when they have to point in - when making skydome....

There were few more things that i just can't remember right now...

Thx for explanation :-)

i am practising pixel and vertex shaders right now, so here is some theory of how the normals look like when u bump map something.

http://www.gamedev.net/reference/articles/article1903.asp

Did not read the whole thing.Just what i needed.Now i get it...

Thanks man