A casual question for a laid back Saturday.

When finding violin notes, is the main method muscle memory OR relative position from the last (fingered) note ? 

Muscle memory simply picks a note by aiming at some point on a fingerboard. 

Relative positioning might be finding a "B" just below a "C" or a "G" just up one string from a "C".

Does anyone ever think about that? 

If finger position is not under control then "relative position" doesn't work very well.  Major teachers such as Applebaum and FM emphasize finger position control.

PS  Shifting, I think, would be ALL muscle memory (?)