Fillet mechanism

 From:  BurrMan
This may have been discussed, but I dont know what its called to check.

The ability to change the "Center" of the fillet between the 2 surfaces. The fillet being more on one surface than the other. Is this called variable also? I interpret variable as being able to have a fillet go from 1 to 4 inches or something. Anyway, saw it in a video and was wondering if it would come to MoI.