public override bool Scatter(Ray r, HitRecord rec, out Vec3f attenuation, out Ray Scattered, Random drand)
{
Vec3f reflected = Vec3f.Reflect(r.Direction.GetNormal(), rec.Normal);
Scattered = new Ray(rec.Point, reflected + Fuzz * RayTrace1.RandomInUnitSphere(drand));
attenuation = Albedo;
return(Vec3f.Dot(Scattered.Direction, rec.Normal) > 0);
}
public Vec3f Random_in_unit_disk(Random drand)
{
Vec3f p;
do
{
p = 2.0f * new Vec3f((float)drand.NextDouble(), (float)drand.NextDouble(), 0) - new Vec3f(1f, 1f, 0);
} while (Vec3f.Dot(p, p) >= 1f);
return(p);
}
public override bool Scatter(Ray r, HitRecord rec, out Vec3f attenuation, out Ray Scattered, Random drand)
{
Vec3f outward_normal;
Vec3f reflected = Vec3f.Reflect(r.Direction, rec.Normal);
float ni_over_nt;
// try 1,1,0 to see color shift, then change to 1,1,1 and see differance.
attenuation = new Vec3f(1.0f, 1.0f, 1.0f);
Vec3f refracted;
float reflect_prob;
float cosine;
if (Vec3f.Dot(r.Direction, rec.Normal) > 0)
{
outward_normal = -rec.Normal;
ni_over_nt = RefIndex;
cosine = RefIndex * Vec3f.Dot(r.Direction, rec.Normal) / r.Direction.GetLength();
}
else
{
outward_normal = rec.Normal;
ni_over_nt = 1.0f / RefIndex;
cosine = -Vec3f.Dot(r.Direction, rec.Normal) / r.Direction.GetLength();
}
if (Vec3f.Refract(r.Direction, outward_normal, ni_over_nt, out refracted))
{
reflect_prob = Schlick(cosine, RefIndex);
//Scattered = new Ray(rec.Point, refracted);
}
else
{
Scattered = new Ray(rec.Point, reflected); // comment out this line?
reflect_prob = 1.0f;
//return false;
}
if (drand.NextDouble() < reflect_prob)
{
Scattered = new Ray(rec.Point, reflected);
}
else
{
Scattered = new Ray(rec.Point, refracted);
}
return(true);
}
public override bool Hit(Ray r, float tMin, float tMax, ref HitRecord record)
{
Vec3f oc = r.Origin - Center;
float a = Vec3f.Dot(r.Direction, r.Direction);
float b = Vec3f.Dot(oc, r.Direction);
float c = Vec3f.Dot(oc, oc) - Radius * Radius;
float discriminant = b * b - a * c;
if (discriminant > 0)
{
float tempSqrt = MathF.Sqrt(b * b - a * c);
float temp = (-b - tempSqrt) / a;
if (temp < tMax && temp > tMin)
{
record.t = temp;
record.Point = r.PointAtParameter(record.t);
record.Normal = (record.Point - Center) / Radius;
record.Material = this.Material;
return(true);
}
temp = (-b + tempSqrt) / a;
if (temp < tMax && temp > tMin)
{
record.t = temp;
record.Point = r.PointAtParameter(record.t);
record.Normal = (record.Point - Center) / Radius;
record.Material = this.Material;
return(true);
}
}
return(false);
}
