LookVector from ViewMatrix?

// get the look vector of the camera from the view matrix
Vector3f vLookVector;
m_mxView.LookVector(&vLookVector);

// calculate the center of the sphere
m_frusSphere.Center() = m_vCameraPosition + (vLookVector * (fViewLen * 0.5f) + m_fNearPlane);


I do not understand what this piece of code is looking for.
What exactly would a look vector be?

Would it be the position of the Player minus the position of the Camera
vPlayerPos - vCameraEye = vForward

I guess it would be a unit vector (length 1) in the direction that the player/camera was looking.

Thats what I figured.

I am just getting some bogus sphere to sphere collision results.
and I believe it has to do with the frustum sphere I am drawing.

My old quadtree node sphere to each of the 6 frustrum plane test worked out great.
Now using the same sphere's and pressing each sphere against the frustum sphere...a ton less tests...but at certain angles the terrain just gets completly culled.

why?