I’m not entirely sure that I understand your goal here.
Are you trying to determine whether or not a vertex is within the frustum of the camera? You can then use isInFrustum(planes) on the vector.
Are you instead trying to determine whether or not another object is in front of the object the vertices belong to? Could you use occlusion culling?
Or are you simply trying to determine whether or not the face belonging to a vertex is facing the camera? You could do some Dot products between the normal of the vertex and the camera direction