Geometry cutoff in Eye Sockets and Neck

Hi,

(In a just a head model) Is it normal that meshes make a hole/cut off the geometry in the eye sockets and under the neck area?
I see it quite often
Why is that?

Since you have an eyeball in the eye you don’t need geometry behind it. As for the neck, there’s some advantages for having the head as a separate object, like controlling animation separately and separate materials. Usually it works OK because there’s a natural separation where the clothing is. Also, some games absolutely require it because they have the ability to customize characters where they switch out head models.

Does having geometry behind the eye affect the rigging process much?