public void RefractedColorOfOpaqueSurfaceIsBlack()
{
var w = World.Default();
var s = w.Objects[0];
var r = new Ray(new Point(0, 0, -5), new Vector(0, 0, 1));
var xs = Intersections.Create(new Intersection(4f, s), new Intersection(6f, s));
var comps = new IntersectionInfo(xs[0], r, xs);
PhongShading.RefractedColor(w, comps, 5).Should().Be(Colors.Black);
}
public void RefractedColorIsBlackIfRemainingBouncesIsZero()
{
var w = World.Default();
var s = w.Objects[0];
s.Material.Transparency = 1.0f;
s.Material.RefractiveIndex = 1.5f;
var r = new Ray(new Point(0, 0, -5), new Vector(0, 0, 1));
var xs = Intersections.Create(new Intersection(4f, s), new Intersection(6f, s));
var comps = new IntersectionInfo(xs[0], r, xs);
PhongShading.RefractedColor(w, comps, 0).Should().Be(Colors.Black);
}
public void RefractedColorIsBlackForTotalInternalRefraction()
{
var w = World.Default();
var s = w.Objects[0];
s.Material.Transparency = 1.0f;
s.Material.RefractiveIndex = 1.5f;
var r = new Ray(new Point(0, 0, MathF.Sqrt(2f) / 2f), new Vector(0, 1, 0));
var xs = Intersections.Create(
new Intersection(-MathF.Sqrt(2f) / 2f, s),
new Intersection(MathF.Sqrt(2f) / 2f, s));
// Inside sphere so look at second intersection.
var comps = new IntersectionInfo(xs[1], r, xs);
PhongShading.RefractedColor(w, comps, 5).Should().Be(Colors.Black);
}
public void RefractsRayWhenHitsTransparentSurface()
{
var w = World.Default();
var a = w.Objects[0];
a.Material.Ambient = 1.0f;
a.Material.Texture = new TestTexture();
var b = w.Objects[1];
b.Material.Transparency = 1.0f;
b.Material.RefractiveIndex = 1.5f;
var r = new Ray(new Point(0, 0, 0.1f), new Vector(0, 1, 0));
var xs = Intersections.Create(
new Intersection(-0.9899f, a),
new Intersection(-0.4899f, b),
new Intersection(0.4899f, b),
new Intersection(0.9899f, a));
var comps = new IntersectionInfo(xs[2], r, xs);
var c = PhongShading.RefractedColor(w, comps, 5);
c.Red.Should().BeApproximately(0f, 0.001f);
c.Green.Should().BeApproximately(0.99888f, 0.001f);
c.Blue.Should().BeApproximately(0.04725f, 0.001f);
}