public void SimpleCameraTest()
{
// Ray cast for screen coordinate 0,0
{
var camera = new SimpleCamera(new Tuple4(0.0, 0.0, -4.0, TupleFlavour.Point), 6.0, 600, 800);
var ray = camera.GetRay(0, 0);
var expectedRay = new Ray(
new Tuple4(0.0, 0.0, -4.0, TupleFlavour.Point),
Tuple4.Normalize(new Tuple4(-3.0, 3.0, 1.0, TupleFlavour.Vector)));
Assert.Equal(expectedRay.origin, ray.origin);
Assert.Equal(expectedRay.dir, ray.dir);
var t = Tuple4.Add(ray.origin, Tuple4.Scale(ray.dir, 4.35890));
Assert.Equal(new Tuple4(-3.0, 3.0, -3.0, TupleFlavour.Point), t);
}
// Ray cast for screen coordinate width,height
{
var camera = new SimpleCamera(new Tuple4(0.0, 0.0, -4.0, TupleFlavour.Point), 6.0, 600, 800);
var ray = camera.GetRay(600, 800);
var expectedRay = new Ray(
new Tuple4(0.0, 0.0, -4.0, TupleFlavour.Point),
Tuple4.Normalize(new Tuple4(3.0, -3.0, 1.0, TupleFlavour.Vector)));
Assert.Equal(expectedRay.origin, ray.origin);
Assert.Equal(expectedRay.dir, ray.dir);
}
{
var camera = new SimpleCamera(new Tuple4(0, 0, -1.0, TupleFlavour.Point), 2.0, 600, 600);
var ray = camera.GetRay(0, 0);
var t = Tuple4.Add(ray.origin, Tuple4.Scale(ray.dir, 1.73205));
Assert.Equal(new Tuple4(-1.0, 1.0, 0.0, TupleFlavour.Point), t);
}
}
public void TupleScaleByTest()
{
var t1 = new Tuple4(1, 7, 3, TupleFlavour.Vector);
var expected = new Tuple4(0.5, 3.5, 1.5, TupleFlavour.Vector);
Assert.Equal(expected, Tuple4.Scale(t1, 0.5));
}
public void Then_scale_scalar3(string a, double s, double t1, double t2, double t3)
{
var c = Tuple4.Scale(cache[a], s);
Assert.True(Constants.EpsilonCompare(t1, c.X));
Assert.True(Constants.EpsilonCompare(t2, c.Y));
Assert.True(Constants.EpsilonCompare(t3, c.Z));
}
public void TupleScaleTest()
{
var t1 = new Tuple4(1, 7, 3, TupleFlavour.Vector);
var t2 = new Tuple4(4, 5, 6, TupleFlavour.Vector);
var expected = new Tuple4(4, 35, 18, TupleFlavour.Vector);
Assert.Equal(expected, Tuple4.Scale(t1, t2));
}
public void Then_scale_vector(string a, string b, double t1, double t2, double t3)
{
var c = Tuple4.Scale(cache[a], cache[b]);
Assert.True(Constants.EpsilonCompare(t1, c.X));
Assert.True(Constants.EpsilonCompare(t2, c.Y));
Assert.True(Constants.EpsilonCompare(t3, c.Z));
Assert.True(c.IsVector());
}
public static Tuple4 GetShadedColor(Tuple4 objectPoint, IMaterial material, Tuple4 white, Tuple4 lightDirection, double intensity, Tuple4 eyeVector, Tuple4 pointOnSurface, Tuple4 surfaceNormal)
{
Tuple4 color = material.GetColor(objectPoint);
Lighting lighting = GetIntensity(material, lightDirection, intensity, eyeVector, pointOnSurface, surfaceNormal);
var shadedColor = Tuple4.Add(
Tuple4.Scale(color, lighting.intensity * lighting.diffuse),
Tuple4.Scale(white, lighting.specular)
);
return(shadedColor);
}
public virtual HitResult[] AllHits(Tuple4 origin, Tuple4 dir)
{
var intersections = GetIntersections(new Ray(origin, dir));
if (intersections == null)
{
return(new HitResult[] { HitResult.NoHit });
}
var result = new HitResult[intersections.Length];
for (int i = 0; i < intersections.Length; ++i)
{
var figure = intersections[i].figure;
var distance = intersections[i].t;
var pointOnSurface = Tuple4.Geometry3D.MovePoint(origin, dir, distance); // orig + dir*dist
// TODO: Remove this cast to BaseFigure
(var surfaceNormal, var objectPoint) = ((BaseFigure)figure).GetTransformedNormal(figure, pointOnSurface, intersections[i].u, intersections[i].v);
var eyeVector = Tuple4.Negate(dir);
var isInside = false;
if (Tuple4.DotProduct(surfaceNormal, eyeVector) < 0)
{
isInside = true;
surfaceNormal = Tuple4.Negate(surfaceNormal);
}
var pointOverSurface = Tuple4.Add(pointOnSurface, Tuple4.Scale(surfaceNormal, Constants.Epsilon));
var pointUnderSurface = Tuple4.Subtract(pointOnSurface, Tuple4.Scale(surfaceNormal, Constants.Epsilon));
var reflectionVector = Tuple4.Reflect(dir, surfaceNormal);
result[i] = new HitResult(true,
figure,
distance,
intersections[i].u,
intersections[i].v,
objectPoint,
pointOnSurface,
pointOverSurface,
pointUnderSurface,
surfaceNormal,
eyeVector,
reflectionVector,
isInside);
}
return(result);
}
public bool IsShadowed(ILight light, Tuple4 pointOverSurface)
{
var lightDir = light.GetLightDirection(pointOverSurface);
if (!lightDir.Equals(Tuple4.ZeroVector))
{
var lh = CalculateIntersection(Tuple4.Add(pointOverSurface, Tuple4.Scale(lightDir, Constants.Epsilon)), lightDir);
if (lh.IsHit)
{
var distance = light.GetLightDistance(pointOverSurface);
if (lh.Distance < distance)
{
return(true);
}
}
}
return(false);
}
private Tuple4 CalculateReflectedColorAt(HitResult hit, int remaining)
{
if (!hit.IsHit || remaining <= 0)
{
return(colors.Black);
}
var material = hit.Figure.Material;
if (Constants.EpsilonZero(material.Reflective))
{
return(Tuple4.ZeroVector);
}
var reflectedRay = new Ray(hit.PointOverSurface, hit.ReflectionVector);
var reflectedColor = CastRay(reflectedRay, remaining - 1);
return(Tuple4.Scale(reflectedColor, material.Reflective));
}
private Tuple4 CalculateColorAt(HitResult hit, double refractiveIndexEntering, double refractiveIndexExiting, int remaining)
{
if (!hit.IsHit)
{
return(colors.Black);
}
var material = hit.Figure.Material;
var surface = Tuple4.ZeroVector;
foreach (var light in lights)
{
// Shadow
if (castShadows && IsShadowed(light, hit.PointOverSurface))
{
continue;
}
surface = Tuple4.Add(surface, light.GetShadedColor(hit.ObjectPoint, material, hit.EyeVector, hit.PointOnSurface, hit.SurfaceNormal));
}
var reflected = CalculateReflectedColorAt(hit, remaining);
var refracted = CalculateRefractedColorAt(hit, refractiveIndexEntering, refractiveIndexExiting, remaining);
Tuple4 color;
if (material.Reflective > 0 && material.Transparency > 0)
{
var reflectance = Schlick(hit, refractiveIndexEntering, refractiveIndexExiting);
color = Tuple4.Add(surface, Tuple4.Add(Tuple4.Scale(reflected, reflectance), Tuple4.Scale(refracted, 1.0 - reflectance)));
}
else
{
color = Tuple4.Add(surface, Tuple4.Add(reflected, refracted));
}
return(new Tuple4(Math.Min(colors.White.X, color.X),
Math.Min(colors.White.X, color.Y),
Math.Min(colors.White.X, color.Z),
TupleFlavour.Vector));
}
private Tuple4 CalculateRefractedColorAt(HitResult hit, double refractiveIndexEntering, double refractiveIndexExiting, int remaining)
{
if (!hit.IsHit || remaining <= 0)
{
return(colors.Black);
}
var material = hit.Figure.Material;
if (Constants.EpsilonZero(material.Transparency))
{
return(colors.Black);
}
// Calculations are based on Snell's law
var ration = refractiveIndexEntering / refractiveIndexExiting;
var cosI = Tuple4.DotProduct(hit.EyeVector, hit.SurfaceNormal);
// sin(t) * sin(t) = (ration * ration) * (1 - cos(I) * cos(I))
var sinTheta2 = ration * ration * (1 - cosI * cosI);
if (sinTheta2 > 1.0)
{
// Total internal reflection
return(colors.Black);
}
var cosTheta = Math.Sqrt(1 - sinTheta2);
var dir = Tuple4.Subtract(Tuple4.Scale(hit.SurfaceNormal, ration * cosI - cosTheta),
Tuple4.Scale(hit.EyeVector, ration));
var refractedRay = new Ray(hit.PointUnderSurface, dir);
var refractedColor = CastRay(refractedRay, remaining - 1);
return(Tuple4.Scale(refractedColor, material.Transparency));
}
protected override Tuple4 GetBaseNormal(IFigure figure, Tuple4 pointOnSurface, double u, double v)
{
return(Tuple4.Add(Tuple4.Scale(N2, u),
Tuple4.Add(Tuple4.Scale(N3, v), Tuple4.Scale(N1, (1.0 - u - v)))));
}
public static Tuple4 GetAmbientColor(Tuple4 objectPoint, IMaterial material)
{
return(Tuple4.Scale(material.GetColor(objectPoint), material.Ambient));
}
protected override Tuple4 GetColorAtPattern(Tuple4 pointInPatternSpace)
{
return(Tuple4.Add(ColorA, Tuple4.Scale(colorDelta, Math.Abs(pointInPatternSpace.X) - Math.Floor(Math.Abs(pointInPatternSpace.X)))));
}
