The radius here is for their spawn trigger, not the NPCs themselves. The triggers are fixed in place, so the circles here wouldn't change.

Explanation: There are two versions of this NPC, depending on which way you approach his lab; one that walks around, and one you can talk to. You can have both spawned by leaving the walking Professor's spawn radius, while barely staying inside the talking Professor's radius, then going back in.

i KNEW IT

(Yes I reposted an old video because I couldn't think of something else in time)

Now that you say it, I should probably link it somewhere on the Cutting Room Floor. It's not the easiest thing to find.
For now here's a download link: mega.nz/file/j3hxBaS...

(also of course it has a Jak and Daxter inspiration lol)

Also fun fact, in the game's official Hashcodes, the planets shown in the orrery are labelled after planets in our real-life solar system, with the Sun, Venus, Mercury, Earth and Mars.
Dunno if it's because the planets are actually named this in the Spyro universe, or if it was just for convenience.

The orrery in the center of this render is weird, because Eurochef is once again showing an unused model referenced by an object, despite something different being hard-coded to show up in-game. This is an early model for the solar system model that sits in the level's center.