Does a royalty have to be paid on eBook content?

I’m writing an educational eBook and am exploring the possiblity of using UE4 for some simple animations both interactive and non-interactive.
The eBook would only contain 2 or 3 of these animations and they would be very limited, just showing how an area can look from different perspectives.
After perusing the EULA and FAQ I can’t determine for sure whether I would have to pay any royalties. There was a very brief mention of movies and animations plus comic book use being exempt but nothing in detail.
Any insight on this would be greatly appreciated.

You have to pay royalties if the book uses the actual engine when displaying the animations. If you use UE4 to create the animations but record them to be played in the eBook with some other technology, then there are currently no royalties due.

No royalties for non-interactive content, so pre-rendered videos or images don’t require royalty. If you have videos for example then you don’t pay royalties, but if you include example files and projects with the book then you would have to pay royalty.

Thanx for the replies and that brings up another question.
As any interactive use in the eBook would be a very small percentage of total content, does anyone know if Epic has a reduced royalty for such usage?
Thanx again,
PS…Is there actually any way to contact this company as I’ve found none???