Learning Blender: A Hands-On Guide to Creating 3D Animated Characters

Setting Up the Scene

Before you start compositing, you need to know what to do first. In our example, there is something that obviously stands out: you need the floor to go away, but you want to keep the shadows it receives from the character so you can composite on top of the real footage.

It’s really simple to do that in Blender Render because there is a setting for the materials that allows you to include an object that only receives shadows while the object itself will be transparent.

Just try it: create a new material for the floor, but in the Properties Editor on the Shadows panel of the Material tab, enable Shadows Only. Also, under Shadows Only, you’ll see a drop-down list: select the option Shadow Only instead of Shadows and Distance. ...