public void ReflectanceIsSignificantAtSmallViewAngles()
{
var s = Spheres.GlassSphere();
var r = new Ray(new Point(0, 0.99f, -2f), new Vector(0, 0, 1));
var xs = Intersections.Create(new Intersection(1.8589f, s));
var comps = new IntersectionInfo(xs[0], r, xs);
var reflectance = PhongShading.Schlick(comps);
reflectance.Should().BeApproximately(0.48873f, 0.0001f);
}
public void ReflectanceIsSmallAtPerpendicularViewAngles()
{
var s = Spheres.GlassSphere();
var r = new Ray(new Point(0, 0, 0), new Vector(0, 1, 0));
var xs = Intersections.Create(new Intersection(-1f, s),
new Intersection(1f, s));
var comps = new IntersectionInfo(xs[1], r, xs);
var reflectance = PhongShading.Schlick(comps);
reflectance.Should().BeApproximately(0.04f, 0.0001f);
}
public void SchlickApproximationForTotalInternalReflectionIsOne()
{
var s = Spheres.GlassSphere();
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));
var comps = new IntersectionInfo(xs[1], r, xs);
var reflectance = PhongShading.Schlick(comps);
reflectance.Should().Be(1f);
}