Digital set extensions?

Hi everyone
I am not new to blender but a questio i have had for a while is how to create a digital set extension. I know about matchmoving, macting the lighting and all that but how do you create a nice blend from the real set to the virtual? when this is done there will be a sharp edge where the real, ends and the virtual begins how can i get a nice blend between the two without it looking like an extended set?
Thanks for any help

Much depends on the nature of the set itself – a sharp edge might not be a disadvantage if it can be matched to some feature of the set construction, and lighting & perspective are properly matched. Building some interactive lighting or shadowing into the composite can help a great deal also.

For soft-edged blends you can use the real-life and/or CGI footage to generate hi-contrast matte plates for use in the compositor, blurring edges where necessary for soft transitions. These can be filtered or painted or both. It’s much like rotoscoping in some ways, and can be tedious work, but also very effective if done well.

So it is possible in Blender?

Yes. Though you may need to do some work in a dedicated 2D package if you need something like film grain or video noise. Blender has several noise algorythms but I haven’t been able to use them to effectively mimic film grain. I’m sure someone out there knows how but it’s fairly simplistic and believable via Photoshop and batch processing. Procedural textures just seem to be too irregularly regular for this. Any type of motion/feature tracking will need to be done externally also thgough we’ll hopefully get this in Blender V2.50.

See here:
http://wiki.blender.org/index.php/BlenderDev/ReconstructionAndMotionTracking

http://wiki.blender.org/index.php/User:Keir/TrackingDiary

http://wiki.blender.org/index.php/User:Keir/TrackingDiary

I’m thinking that libmv project is going to be the motion tracker that’s going to be integrated into Blender. Here’s a link showing a video tracked using it.