Quote: "Screen-Space Effect ( Motion, Depth of Field, Bloom, HDR )"
me thinks reading more carefully.
Just for interest. High Definition Range, and Light Bloom are different effects.
Light Bloom is where it appears that high brightness surfaces are glowing, this is quite an unrealistic effect on it's own unless your using a Camera lens.
High Defintion Range, in the truest sense is the ability to display the low-dark colours to the high-bright colours. Given only the GeForce 6 using 64-bit Colour can technically do this, you create the effect by using a Clamp Effect.
As such when your in darker areas you adjust the colour depth range to compensate to see the darker shaders, so when your transitioning to the lighter areas everything seems bright until you adjust to that light level.
Half-Life 2 (updated) and FarCry use this effect very well. A while back I created my own to mimic human eyes better given our eyes actually adjust quite differently to cameras as purple is the dark colour adjustment (something that Carrots have in abundance, which in-fact they used to be before farmers in Denmark started breeding Orange ones because no one wanted to eat something purple hense why they're attributed to being able to see in the dark) and for light areas we see green first.
If done correctly the effect does look truely amazing.
Quote: "I don't know anything about shaders, but I love how, in Half-Life 2, you can look around and some materials (walls and floors usually) have a shiny 'wet' look to them. Almost like the reflection is a big white square that moves with the eye--- too hard to explain."
By product of the cheap & effective Dot3 Cubemapping. In some instances it looks so real it's awesome (like metals), but in others it can spoil the effect (like woods and masonry).
Most of Half-Life 2 effects only work with high-resolution textures. You have the exact same effects in Doom 3, but because they're using 256x256 rather than 1024x1024 texture the difference is just incredible. Try lowering the Texture Quality to Low (256x256) and all of the Shaders really loose thier quality so much.
The wobble effect where the reflection isn't like a pure reflection but appears to curve with surfaces is due to the Reflection/Refraction mapping. When you combine it post-Bump mapping using the Pixel Normal rather than the Vertex Normal, it allows the surface to alter the reflection to warp it around the normalised texture.
The effect is quite good, and if done properly can be quite quick.
Bump Mapping -> Normal Mapping itself is relatively simplistic, given your just offsetting the pixels based on the light index (taken from the normal either vertex or pixel) normalised by the eye position. Then the final result is projected in object space, well you could just you texture space, but it's easier to combine the cubemap in object space.
when your talking about object space this is the area that the object is rendered in, from the eye point of view. You fill in the information just as if it was a 2D Image, but given your working from a real 3D image and data it provides you with the information you need to create the shading, texture, etc...
