Different shading

[Jike]

I would be very happy if people could give me a few sentences on these things:

So here we go:

Difference between Normal Mapping, Bump Mapping, Height Mapping and SSAO (and how it is created and what it does)

What is displacement Mapping and what is Tesselation? What is Parallax Mapping?

How exactly should I understand phong shading? What does iridescence mean?

Thanks in advance, I hope this clears up some stuff for me

[marks]

Difference between Normal Mapping, Bump Mapping, Height Mapping and SSAO (and how it is created and what it does)

Bump mapping - grey scale texture, height information only
Normal mapping - RGB texture, 3-axis vector information for the direction of the tangent normal of each pixel
Height Map - Same as Bump mapping, but usually used to deform large areas of terrain in a level editor
SSAO (Screen Space Ambient Occlusion) - Same as Ambient Occlusion render effect in a software renderer, however rendered in realtime.

What is displacement Mapping and what is Tesselation? What is Parallax Mapping?

Displacement mapping - same as bump mapping except it actually moves the verts of the mesh instead of just making it be lit differently.
Parallax mapping is essentially a bumpmap which is used in conjunction with a normalmap (greyscale parallax map) to define surface depth better:

Tesselation is a DirectX11 function which dynamically subdivides a mesh based on viewing distance. Its a bit more complicated than that, but this should give you a good idea:

How exactly should I understand phong shading?

Phong mask = specular texture (defines brightness of specular highlight)
Phong exponent = gloss texture (defines size / sharpness of specular highlight)

What does iridescence mean?

Iridescence (also known as goniochromism) is generally known as the property of certain surfaces which appear to change colour as the angle of view changes. Iridescence is commonly seen in items such as soap bubbles, butterfly wings, and sea shells.

[Gary]

I new a lot of that, but not all of it, thanks Marks.

I also think someone a while back got parallax mapping was in Source, but sadly it's broken now.

[Jike]

OH great this helped a lot.

Few questions remain:
-Parallax Mapping, does this mean it is a mixture of the different lighting and the geometry deforming, is it like something similar to Displacement mapping. If so, which differences remain?

Hows does tesselation work? With displacement mapping? are different displacement maps exchanged dynamiclly or is everything intelligently worked out on-the-fly?

also what is the difference then between a phong texture and a specular texture?

thanks for the info so far, this finally clears up some stuff for me

EDIT: Cleared the phong thing up for me:

[marks]

-Parallax Mapping, does this mean it is a mixture of the different lighting and the geometry deforming, is it like something similar to Displacement mapping. If so, which differences remain?

No, there is no geometry deformation, its purely lighting data. I dont know too much about how parallax + normalmaps interact with each other beyond that.

Hows does tesselation work? With displacement mapping? are different displacement maps exchanged dynamiclly or is everything intelligently worked out on-the-fly?

Yes hardware tessellation is used in conjunction with displacement mapping, essentially changing a tesselation level moves "up" a resolution on the displacement texture - at least this is how I understand it. It's kinda like LOD's except with displacement maps and realtime subdividing of the mesh rather than saving different mesh resolutions.

[Vilham]

Phong shading is simply a calculation performed to create semi realistic shading on an object rather than something like Gouraud shading which also does semi realistic shading but uses obviously a different method. I can't remember the exact formula used, I had to learn it in my final year at uni when I was programming using openGL.

[Jike]

Are there any other interesting texture/shading types, you people would like to share with me?

also, why the hell is phong only for models? does it not make sense having it on LightMappedGeneric?

[marks]

Thats down to Valve, a lot of other engines support gloss on BSP type surfaces. As Vilham said, Valve's Phong shader calculates lighting per-pixel rather than per-vertex (VertexLitGeneric uses linear-interpolated vertex shading, aka Gouraud Shading (first other person I've met who knows the actual correct name for that, kudos Vilham)).

That's pretty much it Jike really You covered all the bases pretty well.

[Vilham]

Finally found this:
http://www.cs.nott.ac.uk/~bai/graphics/lighting.pdf

Scroll down to the shading part, it explains all.

[Jike]

well thanks yall