public void RefractedColorWithRay()
{
var w = World.Default;
var s = w.Objects[0];
s.Material.Ambient = 1f;
s.Material.Pattern = new TestPattern();
var b = w.Objects[1];
b.Material.Transparency = 1;
b.Material.IOR = 1.5f;
var r = new Ray(0, 0, .1f, 0, 1, 0);
var xs = new List <Intersection>
{
new(-.9899f, s),
new(-.4899f, b),
new(.4899f, b),
new(.9899f, s)
};
var hit = xs[2];
var comps = IntersectionState.Prepare(ref hit, ref r, xs);
var c = w.RefractedColor(ref comps, 5);
Assert.That.VectorsAreEqual(c, new Color(0, .99888f, .04725f), 1e-3f);
}
public void ChapterVI()
{
const float wallZ = 10f;
const float wallSize = 7f;
const int px = 100;
const float pxSize = wallSize / px;
const float half = wallSize / 2f;
var canvas = new Canvas(px, px);
var rayOrigin = Point(0f, 0f, -5f);
var shape = new Sphere {
Material = new PhongMaterial(new Color(1f, .2f, 1f))
};
var l = new PointLight(Point(-10f, 10f, -10f), Color.White);
Parallel.For(0, px, y =>
{
var wY = half - pxSize * y;
for (var x = 0; x < px; x++)
{
var wx = -half + pxSize * x;
var pos = Point(wx, wY, wallZ);
var ray = new Ray(rayOrigin, Vector4.Normalize(pos - rayOrigin));
var hit = shape.Hit(ref ray);
if (hit == null)
{
continue;
}
var comps = IntersectionState.Prepare(ref hit, ref ray);
canvas[x, y] = shape.Material.Shade(l, ref comps, 0);
}
});
}
public void ShadeHitSchlick()
{
var w = World.Default;
var floor = new Plane(Translation(0, -1, 0))
{
Material = { Transparency = .5f, IOR = 1.5f, Reflectivity = .5f }
};
w.Objects.Add(floor);
var s = new Sphere(Translation(0, -3.5f, -.5f))
{
Material =
{
BaseColor = new Color(1, 0, 0),
Ambient = .5f
}
};
w.Objects.Add(s);
var r = new Ray(0, 0, -3, 0, -MathF.Sqrt(2f) / 2f, MathF.Sqrt(2f) / 2f);
var xs = new Intersection(MathF.Sqrt(2f), floor);
var comps = IntersectionState.Prepare(ref xs, ref r);
var color = w.ShadeHit(ref comps, 5);
Assert.That.VectorsAreEqual(color, new Color(.93391f, .69643f, .69243f), 1e-4f);
}
public void SchlickN2GreaterN1()
{
var s = Sphere.GlassSphere;
var r = new Ray(0, .99f, -2, 0, 0, 1);
var xs = new Intersection(1.8589f, s);
var comps = IntersectionState.Prepare(ref xs, ref r);
Assert.That.FloatsAreEqual(comps.Schlick(), .48873f);
}
public void PrecomputingReflectionVector()
{
var s = new Plane();
var r = new Ray(0f, 1f, -1f, 0f, -MathF.Sqrt(2f) / 2f, MathF.Sqrt(2f) / 2f);
var i = new Intersection(MathF.Sqrt(2f), s);
var comps = IntersectionState.Prepare(ref i, ref r);
Assert.AreEqual(comps.Reflect, Direction(0f, MathF.Sqrt(2f) / 2f, MathF.Sqrt(2f) / 2f));
}
public void HitOccursOutside()
{
var r = new Ray(0f, 0f, -5f, 0f, 0f, 1f);
var s = new Sphere();
var i = new Intersection(4f, s);
var comps = IntersectionState.Prepare(ref i, ref r);
Assert.IsFalse(comps.IsInside);
}
public void HitOffsetsPoint()
{
var r = new Ray(0f, 0f, -5f, 0f, 0f, 1f);
var s = new Sphere(Translation(0f, 0f, 1f));
var i = new Intersection(5f, s);
var c = IntersectionState.Prepare(ref i, ref r);
Assert.IsTrue(c.OverPoint.Z < -Constants.Epsilon / 2f);
Assert.IsTrue(c.Point.Z > c.OverPoint.Z);
}
public void ShadingIntersection()
{
var w = World.Default;
var r = new Ray(0f, 0f, -5f, 0f, 0f, 1f);
var s = w.Objects[0];
var i = new Intersection(4f, s);
var comps = IntersectionState.Prepare(ref i, ref r);
var c = w.ShadeHit(ref comps);
Assert.That.VectorsAreEqual(c, new Color(.38066f, .47583f, .2855f));
}
public void UnderPointIstBelowSurf()
{
var r = new Ray(0, 0, -5, 0, 0, 1);
var s = Sphere.GlassSphere;
s.Transform = Translation(0, 0, 1);
var i = new Intersection(5, s);
var comps = IntersectionState.Prepare(ref i, ref r); //third argument is list of i
Assert.IsTrue(comps.UnderPoint.Z > Constants.Epsilon / 2f);
Assert.IsTrue(comps.Point.Z < comps.UnderPoint.Z);
}
public void HitOccursInside()
{
var r = new Ray(0f, 0f, 0f, 0f, 0f, 1f);
var s = new Sphere();
var i = new Intersection(1f, s);
var comps = IntersectionState.Prepare(ref i, ref r);
Assert.IsTrue(comps.IsInside);
Assert.That.VectorsAreEqual(comps.Point, Point(0f, 0f, 1f));
Assert.That.VectorsAreEqual(comps.Eye, Direction(0f, 0f, -1f));
Assert.That.VectorsAreEqual(comps.Normal, Direction(0f, 0f, -1f));
}
public void PrecomputingStateOfIntersection()
{
var r = new Ray(0f, 0f, -5f, 0f, 0f, 1f);
var s = new Sphere();
var i = new Intersection(4f, s);
var comps = IntersectionState.Prepare(ref i, ref r);
Assert.AreEqual(comps.Distance, i.Distance);
Assert.AreEqual(comps.Object, i.Object);
Assert.That.VectorsAreEqual(comps.Point, Point(0f, 0f, -1f));
Assert.That.VectorsAreEqual(comps.Eye, Direction(0f, 0f, -1f));
Assert.That.VectorsAreEqual(comps.Normal, Direction(0f, 0f, -1f));
}
public void ShadingIntersectionInside()
{
var w = World.Default;
var r = new Ray(0f, 0f, 0f, 0f, 0f, 1f);
var s = w.Objects[1];
w.Lights[0] = new PointLight(Point(0f, .25f, 0f), Color.White);
var i = new Intersection(.5f, s);
var comps = IntersectionState.Prepare(ref i, ref r);
var c = w.ShadeHit(ref comps);
Assert.That.VectorsAreEqual(c, new Color(.90498f, .90498f, .90498f));
}
public void ReflectedColorForNonReflectiveMaterial()
{
var w = World.Default;
var r = new Ray(0f, 0f, 0f, 0f, 0f, 1f);
var s = w.Objects[1];
s.Material.Ambient = 1;
var i = new Intersection(1, s);
var comps = IntersectionState.Prepare(ref i, ref r);
var col = w.ReflectedColor(ref comps);
Assert.That.VectorsAreEqual(col, Color.Black);
}
public void SchlickTotalReflection()
{
var s = Sphere.GlassSphere;
var r = new Ray(0, 0, MathF.Sqrt(2f) / 2f, 0, 1, 0);
var xs = new List <Intersection>
{
new(-MathF.Sqrt(2f) / 2f, s),
new(MathF.Sqrt(2f) / 2f, s)
};
var hit = xs[1];
var comps = IntersectionState.Prepare(ref hit, ref r, xs);
Assert.AreEqual(comps.Schlick(), 1f);
}
public void SchlickPerpendicular()
{
var s = Sphere.GlassSphere;
var r = new Ray(0, 0, 0, 0, 1, 0);
var xs = new List <Intersection>
{
new(-1, s),
new(1, s)
};
var hit = xs[1];
var comps = IntersectionState.Prepare(ref hit, ref r, xs);
Assert.That.FloatsAreEqual(comps.Schlick(), .04f);
}
public void RefractedColorOpaque()
{
var w = World.Default;
var s = w.Objects[0];
var r = new Ray(0, 0, -5, 0, 0, 1);
var xs = new List <Intersection>
{
new(4, s),
new(6, s)
};
var hit = xs[0];
var comps = IntersectionState.Prepare(ref hit, ref r, xs);
Assert.AreEqual(w.RefractedColor(ref comps, 5), Color.Black);
}
public void LimitRecursion()
{
var w = World.Default;
var s = new Plane(Translation(0, -1, 0))
{
Material = { Reflectivity = .5f }
};
w.Objects.Add(s);
var r = new Ray(0, 0, -3, 0, -MathF.Sqrt(2f) / 2f, MathF.Sqrt(2f) / 2f);
var i = new Intersection(MathF.Sqrt(2f), s);
var comps = IntersectionState.Prepare(ref i, ref r);
var col = w.ReflectedColor(ref comps, 0);
Assert.That.VectorsAreEqual(col, Color.Black);
}
public void ShadeHitWithReflective()
{
var w = World.Default;
var s = new Plane(Translation(0f, -1f, 0f))
{
Material = { Reflectivity = .5f }
};
w.Objects.Add(s);
var r = new Ray(0, 0, -3, 0, -MathF.Sqrt(2f) / 2f, MathF.Sqrt(2f) / 2f);
var i = new Intersection(MathF.Sqrt(2f), s);
var comps = IntersectionState.Prepare(ref i, ref r);
var col = w.ShadeHit(ref comps, 5);
Assert.That.VectorsAreEqual(col, new Color(.87677f, .92436f, .82918f), 1e-3f);
}
public void ReflectedColorReflectiveMaterial()
{
var w = World.Default;
var s = new Plane(Translation(0, -1, 0))
{
Material = { Reflectivity = .5f }
};
w.Objects.Add(s);
var r = new Ray(0, 0, -3, 0, -MathF.Sqrt(2f) / 2f, MathF.Sqrt(2f) / 2f);
var i = new Intersection(MathF.Sqrt(2f), s);
var comps = IntersectionState.Prepare(ref i, ref r);
var col = w.ReflectedColor(ref comps, 1);
Assert.That.VectorsAreEqual(col, new Color(.19032f, .2379f, .14274f), 1e-3f);
}
public void RefractedColorUnterTotalReflection()
{
var w = World.Default;
var s = w.Objects[0];
s.Material.Transparency = 1;
s.Material.IOR = 1.5f;
var r = new Ray(0, 0, MathF.Sqrt(2f) / 2f, 0, 1, 0);
var xs = new List <Intersection>
{
new(-MathF.Sqrt(2f) / 2f, s),
new(MathF.Sqrt(2f) / 2f, s)
};
var hit = xs[1];
var comps = IntersectionState.Prepare(ref hit, ref r, xs);
Assert.AreEqual(w.RefractedColor(ref comps, 5), Color.Black);
}
public void RefractedColorLimit()
{
var w = World.Default;
var s = w.Objects[0];
s.Material.Transparency = 1;
s.Material.IOR = 1.5f;
var r = new Ray(0, 0, -5, 0, 0, 1);
var xs = new List <Intersection>
{
new(4, s),
new(6, s)
};
var hit = xs[0];
var comps = IntersectionState.Prepare(ref hit, ref r, xs);
Assert.AreEqual(w.RefractedColor(ref comps, 0), Color.Black);
}
public void FindingN1AndN2()
{
var a = Sphere.GlassSphere;
a.Transform = Scale(2f);
var b = Sphere.GlassSphere;
b.Transform = Translation(0, 0, -.25f);
b.Material.IOR = 2f;
var c = Sphere.GlassSphere;
c.Transform = Translation(0, 0, .25f);
c.Material.IOR = 2.5f;
var r = new Ray(0, 0, -4, 0, 0, 1);
var xs = new List <Intersection>
{
new(2f, a),
new(2.75f, b),
new(3.25f, c),
new(4.75f, b),
new(5.25f, c),
new(6, a)
};
var n1 = new[] { 1, 1.5f, 2, 2.5f, 2.5f, 1.5f };
var n2 = new[] { 1.5f, 2, 2.5f, 2.5f, 1.5f, 1 };
for (var i = 0; i <= 5; i++)
{
var hit = xs[i];
var comps = IntersectionState.Prepare(ref hit, ref r, xs);
Assert.AreEqual(comps.N1, n1[i]);
Assert.AreEqual(comps.N2, n2[i]);
}
}