public void LightOnSurfaceInShadow()
{
var s = new Sphere();
var m = new Material();
var position = Point.Zero;
var eyeV = new Vector(0, 0, -1f);
var normal = new Normal(0, 0, -1);
var light = new PointLight(new Point(0, 0, -10), new Color(1f, 1f, 1f));
var result = PhongShading.Lighting(m, s, light, position, eyeV, normal, 0);
result.Should().BeEquivalentTo(new Color(0.1f, 0.1f, 0.1f));
}
public void FullReflectionOfLightOffset45Deg()
{
var s = new Sphere();
var m = new Material();
var position = Point.Zero;
var eyeV = new Vector(0, -MathF.Sqrt(2) / 2, -MathF.Sqrt(2) / 2);
var normal = new Normal(0, 0, -1);
var light = new PointLight(new Point(0, 10, -10), new Color(1f, 1f, 1f));
var result = PhongShading.Lighting(m, s, light, position, eyeV, normal, 1);
result.Should().BeEquivalentTo(new Color(1.6364f, 1.6364f, 1.6364f));
}
public void LightOnSurfaceInPartialShadow()
{
var s = new Sphere();
var m = new Material {
Ambient = 0.1f, Diffuse = 0.9f, Specular = 0
};
var position = new Point(0, 0, -1);
var eyeV = new Vector(0, 0, -1f);
var normal = new Normal(0, 0, -1);
var light = new PointLight(new Point(0, 0, -10), new Color(1f, 1f, 1f));
var result = PhongShading.Lighting(m, s, light, position, eyeV, normal, 0.5f);
result.Should().BeEquivalentTo(new Color(0.55f, 0.55f, 0.55f));
}
public void LightingWithPatternApplied()
{
var s = new Sphere();
var m = new Material
{
Texture = new StripeTexture(Colors.White, Colors.Black),
Ambient = 1f,
Diffuse = 0f,
Specular = 0f
};
var eye = new Vector(0, 0, -1);
var normal = new Normal(0, 0, -1);
var light = new PointLight(new Point(0, 0, -10), Colors.White);
var c1 = PhongShading.Lighting(m, s, light, new Point(0.9f, 0, 0), eye, normal, 1);
var c2 = PhongShading.Lighting(m, s, light, new Point(1.1f, 0, 0), eye, normal, 1);
c1.Should().Be(Colors.White);
c2.Should().Be(Colors.Black);
}
public void RaycastTest()
{
const int canvasPixels = 100;
var canvas = new Canvas(canvasPixels, canvasPixels);
var s = new Sphere {
Material = { Texture = new SolidColor(new Color(0.4f, 0.2f, 1)) }
};
var light = new PointLight(new Point(-10, 10, -10), new Color(1f, 1f, 1f));
//var t = Transforms.Shear(0.1f, 0, 0, 0, 0, 0).Scale(0.9f, 1f, 1f);
//s.SetTransform(t);
var rayOrigin = new Point(0f, 0f, -5f);
const float wallZ = 10f;
const float wallSize = 7.0f;
const float pixelSize = wallSize / canvasPixels;
const float half = wallSize / 2;
for (var y = 0; y < canvasPixels; y++)
{
var worldY = half - pixelSize * y;
for (var x = 0; x < canvasPixels; x++)
{
var worldX = -half + pixelSize * x;
var position = new Point(worldX, worldY, wallZ);
var r = new Ray(rayOrigin, (position - rayOrigin).Normalize());
var xs = s.Intersects(r);
var hit = xs.Hit();
if (!hit.HasValue)
{
continue;
}
var point = r.Position(hit.Value.T);
var shape = hit.Value.Geometry;
var normal = shape.NormalAt(point, hit.Value);
var eye = -r.Direction;
var color = PhongShading.Lighting(shape.Material, shape, light, point, eye, normal, 1);
canvas.WritePixel(color, x, y);
}
}
PPM.ToFile(canvas, Environment.GetFolderPath(Environment.SpecialFolder.MyPictures), "raycast");
}
public void CalculateLightingWithAreaLight()
{
var corner = new Point(-0.5f, -0.5f, -5);
var v1 = new Vector(1, 0, 0);
var v2 = new Vector(0, 1, 0);
var light = new AreaLight(corner, v1, 2, v2, 2, Colors.White);
var s = new Sphere
{
Material = { Ambient = 0.1f, Diffuse = 0.9f, Specular = 0f, Texture = new SolidColor(Colors.White) }
};
var eye = new Point(0, 0, -5);
var pt = new Point(0, 0, -1);
var eyeV = (eye - pt).Normalize();
var normal = new Normal(pt.X, pt.Y, pt.Z);
var r = PhongShading.Lighting(s.Material, s, light, pt, eyeV, normal, 1.0f);
r.Should().Be(new Color(0.9965f, 0.9965f, 0.9965f));
pt = new Point(0, 0.7071f, -0.7071f);
eyeV = (eye - pt).Normalize();
normal = new Normal(pt.X, pt.Y, pt.Z);
r = PhongShading.Lighting(s.Material, s, light, pt, eyeV, normal, 1.0f);
r.Should().Be(new Color(0.6232f, 0.6232f, 0.6232f));
}