Authors:

Had we had all the money in the world to spend and we were doing another studio movie, we probably would have jumped quickly into the Necromonger universe and done an Orpheus Descending movie there. We didn't have that kind of resource. So, we said, this time, "If not that, this time, then what is it? What does this new movie look like?" Quickly, just in talking about it very simply with Vin [Diesel] in his kitchen, we decided on a survival, left-for-dead story, where Riddick could, as a character, reclaim the animal side.

Source: collider.com
Had we had all the money in the world to spend and we were doing another studio movie, we probably would have jumped quickly into the Necromonger universe and done an Orpheus Descending movie there. We didn't have that