Just for sex? I guess not. I'd say there are certain limits both ways.
I'll explain the rest with a math equation because that's super erotic.
x = physical desire.
y = personality, interests, etc.
Then if,
ax + by > C,
where a and b are constants that determine x and y's relative importance to one another and C is the constant that describes the minimum combined love score.
From my previous statement, it is obvious that a, b =/= 0. Otherwise, enough personality or enough hotness could conceivably lead to enough C, which is not possible.
I hope this was helpful.