Remember when he said BB-8 wasn’t possible even though it was an actual remote controlled droid rolling around actual sand?

It wasn’t though.

…stackexchange.com/…/how-does-bb-8-move-in-the-sa…

There were multiple different versions of the BB8 prop, and the ones where it is moving quickly, well, it’s moving over a thin layer of sand on top of something more solid, and he’s got a rig attached to him, that was green screened out.

Neil was basically right, something like BB8 would have terrible traction over sand dunes.

… and it did:

We built the trikes because we needed a stable driving version. We motorized the ball and had the head move around on top by means of a curved track system. Motorized castors on the back allowed us to steer it. That version could go over pretty much any terrain. The only thing that defeated it was deep, very fine sand. - Josh Lee

The other versions were puppets, with green screened out pupeteers and control arms.

You fell for a marketing campaign.

They absolutely did not build a real world BB8 capable of independtly doing everything it does in the movies.