public void NormalPointOnZ()
{
var sphere = new Sphere();
var pt = Tuple3D.Point(0, 0, 1);
var expected = Tuple3D.Vector(0, 0, 1);
var actual = sphere.NormalAt(pt);
Assert.That(actual, Is.EqualTo(expected));
}
public void NormalIsNormalizedVector()
{
var sphere = new Sphere();
var weirdVal = Math.Sqrt(3) / 3.0;
var pt = Tuple3D.Point(weirdVal, weirdVal, weirdVal);
var actual = sphere.NormalAt(pt);
var actualNormalized = actual.Normalize();
Assert.That(actual, Is.EqualTo(actualNormalized));
}
public void NormalPointOnNonaxialPoint()
{
var sphere = new Sphere();
var weirdVal = Math.Sqrt(3) / 3.0;
var pt = Tuple3D.Point(weirdVal, weirdVal, weirdVal);
var expected = Tuple3D.Vector(weirdVal, weirdVal, weirdVal);
var actual = sphere.NormalAt(pt);
Assert.That(actual, Is.EqualTo(expected));
}
public void NormalOnTranslatedSphere()
{
var sphere = new Sphere
{
Transform = Transformation.Translation(0, 1, 0)
};
var pt = Tuple3D.Point(0, 1.70711, -0.70711);
var expected = Tuple3D.Vector(0, 0.70711, -0.70711);
var actual = sphere.NormalAt(pt);
Assert.That(actual, Is.EqualTo(expected));
}
public void NormalOnTransformedSphere()
{
var sphere = new Sphere
{
//Transform = Transformation.Scaling(1, 0.5, 1) * Transformation.RotationZ(Math.PI/5.0)
Transform = Transformation.Scaling(1, 0.5, 1)
.RotateZ(Math.PI / 5.0)
};
var pt = Tuple3D.Point(0, Math.Sqrt(2) / 2.0, -Math.Sqrt(2) / 2.0);
var expected = Tuple3D.Vector(0, 0.97014, -0.24254);
var actual = sphere.NormalAt(pt);
Assert.That(actual, Is.EqualTo(expected));
}
