a while ago i made an interactive bathroom visualization, which can be found here : http://forums.epicgames.com/showthread.php?t=774897
since then i received several requests to make a tutorial. so here it is - im gonna cover the various glass materials i made in this scene.
lets start then :
the most important thing to learn in CG (and UDK for that matter) is studying reference, understanding how materials look and behave in real world and trying to replicate it in CG world.
Window glass material :
im gonna start with the easiest one which is the window glass.
its a pretty straight forward material. basically its just a transparent plane with fresnel reflection on it. but from carefully observing this material in real world, you can see that due to the multiple glass planes in today's windows, there seem to be multiple reflections visible. also the glass plane is not a perfectly smooth surface so the world refracting behind it seems to be very subtly distorted. so why not recreate this in udk ?
-this is how the shader network looks. for the window glass i used only one mesh, so to imitate the multiple glass look, i duplicated the reflection, and faked the duplicate with bump offset node - so it looks shifted from the first one.
Solid Glass Shader :
this material is made out of a single cubemap. one neat trick you can do with cubemaps is. that it can be used not only for reflections, but it can also create a very neat and realistic refraction.
all you need to do is swap the textures in the cubemap - as seen above. this will result in a flipped reflection - that will give the illusion of transparent material refracting the world behind it
after that, you'll just stack the cubemaps over. thats about it. i also made the glass just a bit transparent to make an illusion of light wrapping around the material.
this method can be used for solid material like this, or a water in a glass or bottle and so on.
im not sure how long a single post can be, so ill continue in the next post