OK, well I put together a quickie video tutorial that shows how to create and render this image using Final Gather in Mental Ray:
The link to the tut is:
The 6.27MB ZIP file contains:
(1) The TSCC codec that you will need to install before you can watch the video.
(2) The TSCC encoded AVI file.
Sorry it's so large but I didn't add sound so I tended to linger a little on each click of the mouse so you could see what is going on.
A quick note: I hope that the mods and everyone at SM dont mind me posting my homemade video tutorial. I purposefully branded it with "Originally posted at SimplyMaya.Com" so that anyone who sees it will know that where it came from but that it is not an official SM product. If there is a Mental Ray/FG vid in the works or you'd just rather that I didn't post this, please let me know ASAP and I will take down the link
That'll do donkey... that'll do...