I try to create the demo in this blog post http://www.coronalabs.com/blog/2013/09/03/augmented-reality-experiment/, but the line
crate.fill = { type="camera" }
appears to do nothing.
That’s not in yet. It’s still in the experimental phase 
Ok, maybe in next beta build. 
That’s not in yet. It’s still in the experimental phase
Ok, maybe in next beta build.