Ray intersection with 3D quads in XNA?

Question

So I have successfully made a ray the represents the mouse unprojected into the world, and now I need to check if that ray can intersect with a quad object, here is the code

Answer 1

I'm not sure exactly what they mean by "distance along the normal from the origin", but I would assume it just mean the distance from the origin. You can get that from the length property on a Vector3.

If that doesn't work, there is also a constructor for plane which takes three points on the plane:

public Plane (
     Vector3 point1,
     Vector3 point2,
     Vector3 point3
)

You can use this with any 3 points on the plane, such as the corners of your quad, to create a plane.