How to calculate the view vector in Phong Lighting Model? All the books and reference I have read say that the view vector is calculated by subtracting the point where eye is at, from the point where we want to calculate light. But since, eye is at (0, 0, 0) the view vector would be just the negative of the point where eye is at? Is my understanding correct?
EDIT

While the basic principle of vector calculation below is correct, as Sebastián Mestre pointed out, in lighting you would use the vector from the lighted fragment to the eye position. Therefore, you would in fact use $v = -(point - eye) = eye - point = -point$, so you were actually correct in your "negative" assumption. Still (what might have been more a typo than a misunderstanding), it is the negative position of the lighted fragment, rather than the negative eye (which would still be the origin).

As Sebastián also said in a comment to you, you would usually normalize the view vector after you have calculated it. Sebastián is the MVP.



Calculating a vector $v$ from point $A$ to point $B$ is subtracting the values of $B$ from $A$:

$v = \left(\begin{array}{c}x\\y\\z\end{array}\right) = B - A = \left(\begin{array}{c}b_x - a_x\\b_y-a_y\\b_z-a_z\end{array}\right)$

So in your case, you need to subtract the $eye$ point from the point you're calculating light ($pos$) for:

$
v = point -eye
$

Your $eye$ is the origin, so remaining is only the $point$. Therefore: no, it is not the negative position of the lighted point, but the positive position.