public void IsVisible()
{
PerspectiveCamera camera = new PerspectiveCamera
{
Position = new Point3D(0, 0, 100),
LookDirection = new Vector3D(0, 0, -1),
UpDirection = new Vector3D(0, 1, 0)
};
Assert.True(camera.IsVisible(new Point3D(0, 0, 0)));
Assert.True(camera.IsVisible(new Point3D(0, 0, 0), .8));
}
