public Plane(Vec origin, Vec x, Vec y)
{
_origin = origin;
X = x;
Y = y;
Z = Vec.Cross(X, Y);
}
public Plane(Vec origin, Vec z)
{
_origin = origin;
//try constructing x and y
Z = z;
X = Vec.Dot(Z, new Vec(1, 0, 0)) == 1 ? new Vec(0, 1, 0): new Vec(1, 0, 0);
Y = Vec.Cross(Z, X);
}