Guardians of the Galaxy Vol. 2 director James Gunn recently sat down with Fandango to talk out the latest Marvel movie. In the interview, he revealed some very interesting details about Baby Groot, Ego the Living Planet and lots and lots of dancing.

Among the most interesting points James Gunn touches upon, one of the highlights is some nice bit of information on Ego the Living Planet. The latest Guardians trailer already revealed Ego (Kurt Russell) is Peter Quill’s father. But he’s also a planet. So how on Earth did they actually create the set? Was it all CGI? Mr. Gunn had a very interesting answer and it involved a huge set.

When you build a visual effect set – a set that’s completely comprised of visual effects – it’s composed of a certain number of polygons. And the biggest visual effects set ever is Ego’s planet, which is composed of literally trillions of polygons. It’s an enormous set. Every angle is different; you can move through it in a lot of different places.

It’s one of those sets that you just can’t build practically because it’s the exterior and interior of a planet. You aren’t able to make it practically in any way – the closest wall is thousands of feet back. They started working on [those effects] long before we finished shooting over a year ago. They’ve been working on those for a long, long time and they still aren’t done.

Guardians of the Galaxy Vol. 2 will focus heavily on the relationships between characters. Among the characters joining the main cast are Nebula (Karen Gilian), Mantis (Pom Klementieff) and Yondu (Michael Rooker). So it makes sense that there is new tension with these new characters, which was actually his favorite part of the movie.

My favorite part is the center emotional storylines. The stuff between Ego and Quill; between Nebula and Gamora; between Rocket and Yondu. These are all sort of new family relationships that have a lot of deep emotional aspects to them. It’s fun to make them play in this huge action-adventure film.

Speaking of Yondu, Gunn has high praise for Michael Rooker’s performance and started his unofficial Oscar nomination campaign.

A few of the other things Gunn goes overs in the interview is Baby Groot’s dancing moves—of which there will be a lot—an apparently crazy cool opening credits scene and if Kurt Russell (Ego) and Sylvester Stallone’s (unknown character) roles if Guardians will possibly carry beyond this movie—they will.

But one question he refuses to take the bait is on if there will be a Guardians of the Galaxy 3 and if he will direct it. He does go into detail about how less stressful it was to direct that sequel than the first movie. The whole interview is really interesting.

Guardians of the Galaxy Vol. 2 is in theaters May 5.