Thanks Bidoofdude

It's a mixture of both but mainly a lot of green screen. The building behind Powerglide and the rubble behind Bombshell are the main sets as well as the pillar that falls on Powerglide.

I think as I go I'll introduce a lot more of the sets with just a green screen backdrop for the distance.

If you're thinking of getting some sets I think 28mm scale Wargaming Terrain works perfectly for the Combiner Wars figures.

The ones in the video are called "Battlefield in a Box"