public bool Intersects(Ray ray, out double distance)
{
distance = 0.0;
if (Contains(ray.Start))
return true;
double t1 = (Min.X - ray.Start.X) * ray.DirFrac.X;
double t2 = (Max.X - ray.Start.X) * ray.DirFrac.X;
double t3 = (Min.Y - ray.Start.Y) * ray.DirFrac.Y;
double t4 = (Max.Y - ray.Start.Y) * ray.DirFrac.Y;
double t5 = (Min.Z - ray.Start.Z) * ray.DirFrac.Z;
double t6 = (Max.Z - ray.Start.Z) * ray.DirFrac.Z;
double tmin = Math.Max(Math.Max(Math.Min(t1, t2), Math.Min(t3, t4)), Math.Min(t5, t6));
double tmax = Math.Min(Math.Min(Math.Max(t1, t2), Math.Max(t3, t4)), Math.Max(t5, t6));
// if tmax < 0, ray (line) is intersecting AABB, but whole AABB is behind us
if (tmax < 0.0)
return false;
// if tmin > tmax, ray doesn't intersect AABB
if (tmin > tmax)
return false;
distance = tmin;
return true;
}
public override Intersection Intersects(Ray ray)
{
double denom = Vector3.DotProduct(normal, ray.Direction);
if (Math.Abs(denom) > 0.0001)
{
double t = Vector3.DotProduct(position - ray.Start, normal) / denom;
if (t > 0.0005)
return new Intersection(t, ray.PointAt(t), this, normal, null);
}
return Intersection.False;
}
public override Intersection Intersects(Ray ray)
{
Intersection closestIntersec = Intersection.False;
closestIntersec.Distance = double.MaxValue;
foreach (Triangle tri in Triangles)
{
Intersection res = tri.Intersects(ray);
if (res.Intersects && res.Distance > 0.0005 && res.Distance < closestIntersec.Distance)
closestIntersec = res;
}
return closestIntersec;
}
public override Intersection Intersects(Ray ray)
{
Vector3 T = ray.Start - Vertex0.Position;
Vector3 P = Vector3.CrossProduct(ray.Direction, E2);
Vector3 Q = Vector3.CrossProduct(T, E1);
double denom = Vector3.DotProduct(P, E1);
if (Math.Abs(denom) > 0.0001)
{
double u = Vector3.DotProduct(P, T) / denom;
double v = Vector3.DotProduct(Q, ray.Direction) / denom;
double t = Vector3.DotProduct(Q, E2) / denom;
bool kl = denom < 0.0;
if ((u >= 0.0 && u <= 1.0) && (v >= 0.0 && u + v <= 1.0))
return new Intersection(t, ray.PointAt(t), this, kl ? Normal : Normal.Negated, new Vector2(u, kl ? v : 1 - v)); // (kl ? v : 1-v) automatic texture flipping
}
return Intersection.False;
}
private void DrawRay(Color color, Ray ray)
{
Vector2 start = new Vector2(ray.Start.X, ray.Start.Z);
Vector2 center = VectorToPixel(start);
double ellipseRadius = 50.0 / areaSize;
g.FillEllipse(new SolidBrush(color), (int)(center.X - ellipseRadius), (int)(center.Y - ellipseRadius), (int)(ellipseRadius * 2), (int)(ellipseRadius * 2));
Pen p = new Pen(color, 2f);
Vector2 dir = new Vector2(ray.Direction.X, ray.Direction.Z).Normalized;
DrawLine(p, start, start + dir * 2);
}
public override Intersection Intersects(Ray ray)
{
Intersection interT1 = T1.Intersects(ray);
Intersection interT2 = T2.Intersects(ray);
Intersection res = Intersection.False;
if (!interT1.Intersects && !interT2.Intersects)
return res;
if (interT1.Intersects && !interT2.Intersects)
res = interT1;
if (!interT1.Intersects && interT2.Intersects)
res = interT2;
res = interT1.Distance < interT2.Distance ? interT1 : interT2;
if (res.Object == T2)
{
res.BaryCoords.X = 1.0 - res.BaryCoords.X;
res.BaryCoords.Y = 1.0 - res.BaryCoords.Y;
}
res.Object = this;
return res;
}
public override Intersection Intersects(Ray ray)
{
double a = Vector3.DotProduct(ray.Direction, ray.Direction);
double b = 2 * Vector3.DotProduct(ray.Direction, ray.Start - Position);
Vector3 rayToCenter = ray.Start - Position;
double c = Vector3.DotProduct(rayToCenter, rayToCenter) - radius2;
double dis = b * b - 4 * a * c;
if (dis >= 0.0)
{
double t = (-Math.Sqrt(dis) - b) / (2.0 * a);
Vector3 point = ray.PointAt(t);
return new Intersection(t, point, this, (point - Position).Normalized, null);
}
return Intersection.False;
}
public abstract Intersection Intersects(Ray ray);
private Vector3 Trace(Ray ray, int depth)
{
if (depth > 3)
return Vector3.Zero;
Intersection res = IntersectScene(ray);
if (!res.Intersects)
return backgroundColor;
// lights!
double lambertAmount = EvalLights(res);
IObject obj = res.Object;
Material mat = materials[obj.Material];
Vector3 objColor = obj.EvalMaterial(res, mat);
Vector3 resultColor = objColor * mat.Ambient + objColor * lambertAmount * mat.Lambert;
//if (specular != 0.0)
//{
// Ray reflected = ray.Reflect(res.Point, res.Normal);
// reflected.Start += reflected.Direction * 0.001;
// Color? reflectColor = Trace(reflected, depth + 1);
// if (reflectColor.HasValue)
// resultColor += new Vector(reflectColor.Value) * specular;
//}
return resultColor;
}
private Intersection IntersectSceneExcept(Ray ray, params IObject[] objs)
{
Intersection closestIntersec = Intersection.False;
closestIntersec.Distance = double.MaxValue;
foreach (var o in objects.Except(objs))
{
Intersection res = o.Intersects(ray);
if (res.Intersects && res.Distance > 0.0005 && res.Distance < closestIntersec.Distance)
closestIntersec = res;
}
return closestIntersec;
}
private double GetAmbientOcclusion(Intersection res, int rays)
{
int notblocked = 0;
for (int i = 0; i < rays; i++)
{
//Vector2 sample = pdisk_64[i];
double theta = 2 * Math.PI * MwcRng.GetUniform();
double phi = Math.Acos(MwcRng.GetUniform() * 2 - 1);
Vector3 rand = new Vector3(
Math.Cos(theta) * Math.Sin(phi),
Math.Sin(theta) * Math.Sin(phi),
Math.Cos(phi)
);
if (Vector3.DotProduct(rand, res.Normal) < 0.0)
rand.Negate();
Ray newray = new Ray(res.Point, rand);
Intersection res2 = IntersectSceneExcept(newray, res.Object);
if (!res2.Intersects)
notblocked++;
}
return notblocked * 1.0 / rays;
}
