Do any HDR camera sensor plugins exist?

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I'm currently building a simulation which needs to reproduce camera images in challenging lighting environments. This will require rending a camera frame using HDR techniques and allowing control over the exposure settings. In a nut shell this plugin will need to render to a frame buffer that contains floating point values representing light intensity in lumens instead of 8 bit color values.

I have played around with the OGRE HDR examples looking to build a plugin to be able to do this, but I wanted to find if anyone else had aleady done this. I don't want to re-invent the wheel here!

Thanks.