I'm trying to understand what HDR is and how it works.

I understand the basic concepts and have an slight idea of how it is implemented with D3D/hlsl.

However it's still pretty foggy.

Say I'm rendering a sphere with a texture of the earth and a small point list of vertices to act as stars, how would I render this in HDR ?

Here are a few things I'm confused about:

• I'm guessing, I can't use just any basic image format for the texture as the values would be limited to [0, 255] and clamped to [0, 1] in a shader. Same goes for the back buffer, I take it the format needs to be a float point format ?

• What are the other steps involved ? Surely there has to be more than just using floating point formats to render to a render target and then apply some bloom as a post process ? (considering the output will be 8bpp anyway)

Basically, what are the steps for HDR ? How does it work ? I can't seem to find any good papers / articles that describe the process, other than this one, but it seems to skim over the basics a little, so it's confusing.