Green Screen keying is fairly easy with the use of a few tools.  One of the greatest things I have found is this custom made lot called Green Screen Movie lot I am not sure who made it as I downloaded lots of well, lots.  So I do apologize to the creator of this wonderful lot, for not being able to give him or her their just do credit.  

downloads/greenscreenmovielot.rar

Use this lot it has a green room setup with musical instruments.  I filmed in this room the walls and floors are green.  For this test shot, which means, I wanted to make a video and had no script, idea or clue which way to go.  So I saw this room and decide to film.  I set the Sims to learning the instruments.  I used a really nice tool called the InSIMenator you can find the download on www.InSIMenator.net  This tool will allow you to keep your Sims mood maxed.  You can do all kinds of cheats with this one tool.   For this video I just use the InSIMenator to keep the mood of my Sims happy while they learned to play their instrument.

downloads/InSIMenator (UV) v2.7b SIM Edition.zip

Last tool that I used on this video is GunMod's Camera Mod 3.1 This Mod changes the camera controls.  This mod is HIGHLY recommend.  These controls will allow you to get shots that otherwise are not possible.

downloads/MTS2_GunMod_159909_GCM-31-C.zip

Ok now you have all the tools that I used.   Load the lot to you town, and film away. Then load the footage into what every editing software you have.  I use Adobe Premiere,  Most software has some form of keying, found in the Video Effects folder in most cases.    Premiere has a green screen preset.  but if you have chroma keying you can still accomplish.  Play with the chroma settings to get the desired effect. 

What to put behind your cast?  We for this test I used a generic stock footage piece that came with some of my software.  You can use what every your imagination can come up with.  This technique can be use for several reason and many different ways.  Let your imagination go wild and see just what you can do.

I will be added more Ideas using this technique.  Send me links to your work and I will post it here at PsiRaptor.com

This video is just a test piece so the quality was saved at a lower rate the file uploaded to YouTube was only 2.02mb