public override Vector3 GetColor(ShadeRec sr)
{
float x = sr.LocalHitPoint.X;
float y = sr.LocalHitPoint.Y;
float z = sr.LocalHitPoint.Z;
float x_size = b.X / num_x_checkers; // in radians - azimuth angle
float z_size = a.Z / num_z_checkers;
int i_phi = MathHelper.Floor(x / x_size);
int i_theta = MathHelper.Floor(z / z_size);
float f_phi = x / x_size - i_phi;
float f_theta = z / z_size - i_theta;
float phi_line_width = 0.5f * x_line_width;
float theta_line_width = 0.5f * z_line_width;
bool in_outline = (f_phi < phi_line_width || f_phi > 1.0 - phi_line_width) ||
(f_theta < theta_line_width || f_theta > 1.0 - theta_line_width);
if ((i_phi + i_theta) % 2 == 0)
{
if (!in_outline)
return (color1);
}
else
{
if (!in_outline)
return (color2);
}
return (line_color);
}
public override bool Hit(Ray ray, ref float tmin, ref ShadeRec sr)
{
if (bbox.Hit(ray))
return base.Hit(ray, ref tmin, ref sr);
else
return false;
}
public override Vector3 Global_Shade(ShadeRec sr)
{
if (sr.Depth == 1)
return (Vector3.Zero);
else
return ls * t.GetColor(sr);
}
public override Vector3 Area_Light_Shade(ShadeRec sr)
{
Vector3 wo = -sr.Ray.Direction;
Vector3 L = ambient.RHO(sr, wo) * sr.World.AmbientLight.L(sr);
int num_lights = sr.World.Lights.Count;
for (int j = 0; j < num_lights; j++)
{
Light light_ptr = sr.World.Lights[j];
Vector3 wi = light_ptr.GetDirection(sr); //compute_direction ?
wi.Normalize();
float ndotwi = Vector3.Dot(sr.Normal, wi);
float ndotwo = Vector3.Dot(sr.Normal, wo);
if (ndotwi > 0.0 && ndotwo > 0.0)
{
bool in_shadow = false;
if (sr.World.Lights[j].Shadows)
{
Ray shadow_ray = new Ray(sr.HitPoint, wi);
in_shadow = light_ptr.InShadow(shadow_ray, sr);
}
if (!in_shadow)
L += diffuse.F(sr, wo, wi) * light_ptr.L(sr) * light_ptr.G(sr) * ndotwi / sr.World.Lights[j].PDF(sr);
}
}
return (L);
}
public override Vector3 GetColor(ShadeRec sr)
{
float x = sr.LocalHitPoint.X - center.X;
float y = sr.LocalHitPoint.Y - center.Y;
float z = sr.LocalHitPoint.Z - center.Z;
float phi = MathHelper.Atan2(x, z);
float phi_size = 2 * MathHelper.PI / num_angular_checkers;
float theta_size = radius / num_radial_checkers;
float ra = MathHelper.Sqrt(x * x + z * z) / radius;
int i_phi = MathHelper.Floor(phi / phi_size);
int i_theta = MathHelper.Floor(ra / theta_size);
float f_phi = phi / phi_size - i_phi;
float f_theta = ra / theta_size - i_theta;
float phi_line_width = 0.5f * angular_line_width;
float theta_line_width = 0.5f * radial_line_width;
bool in_outline = (f_phi < phi_line_width || f_phi > 1.0 - phi_line_width) ||
(f_theta < theta_line_width || f_theta > 1.0 - theta_line_width);
if ((i_phi + i_theta) % 2 == 0)
{
if (!in_outline)
return (color1);
}
else
{
if (!in_outline)
return (color2);
}
return (line_color);
}
public override bool Hit(Ray ray, ref float tmin, ref ShadeRec sr)
{
Vector3 v0 = (Mesh.Vertices[index0]);
Vector3 v1 = (Mesh.Vertices[index1]);
Vector3 v2 = (Mesh.Vertices[index2]);
float a = v0.X - v1.X, b = v0.X - v2.X, c = ray.Direction.X, d = v0.X - ray.Position.X;
float e = v0.Y - v1.Y, f = v0.Y - v2.Y, g = ray.Direction.Y, h = v0.Y - ray.Position.Y;
float i = v0.Z - v1.Z, j = v0.Z - v2.Z, k = ray.Direction.Z, l = v0.Z - ray.Position.Z;
float m = f * k - g * j, n = h * k - g * l, p = f * l - h * j;
float q = g * i - e * k, s = e * j - f * i;
float inv_denom = 1.0f / (a * m + b * q + c * s);
float e1 = d * m - b * n - c * p;
float beta = e1 * inv_denom;
if (beta < 0.0)
return (false);
float r = e * l - h * i;
float e2 = a * n + d * q + c * r;
float gamma = e2 * inv_denom;
if (gamma < 0.0)
return (false);
if (beta + gamma > 1.0)
return (false);
float e3 = a * p - b * r + d * s;
float t = e3 * inv_denom;
if (t < MathHelper.Epsilon)
return (false);
tmin = t;
sr.Normal = interpolate_normal(beta, gamma); // for smooth shading
sr.LocalHitPoint = ray.Position + t * ray.Direction;
return (true);
}
public override Vector3 Sample_F(ShadeRec sr, Vector3 wo, ref Vector3 wi, ref float pdf)
{
float ndotwo = Vector3.Dot(sr.Normal, wo);
wi = -wo + 2.0f * sr.Normal * ndotwo;
pdf = Vector3.AbsDot(sr.Normal, wi);
return kr * cr.GetColor(sr);
}
public override Vector3 Area_Light_Shade(ShadeRec sr)
{
Vector3 wo = -sr.Ray.Direction;
Vector3 L = ambient.RHO(sr, wo) * sr.World.AmbientLight.L(sr);
int num_lights = sr.World.Lights.Count;
for (int j = 0; j < num_lights; j++)
{
Vector3 wi = sr.World.Lights[j].GetDirection(sr);
float ndotwi = Vector3.Dot(sr.Normal, wi);
if (ndotwi > 0.0)
{
if (Shadows)
{
bool in_shadow = false;
if (sr.World.Lights[j].Shadows)
{
Ray shadowRay = new Ray(sr.HitPoint, wi);
in_shadow = sr.World.Lights[j].InShadow(shadowRay, sr);
}
if (!in_shadow)
L += (diffuse.F(sr, wo, wi)
+ specular.F(sr, wo, wi)) * sr.World.Lights[j].L(sr) * ndotwi * sr.World.Lights[j].G(sr) / sr.World.Lights[j].PDF(sr);
}
else
{
L += (diffuse.F(sr, wo, wi)
+ specular.F(sr, wo, wi)) * sr.World.Lights[j].L(sr) * ndotwi * sr.World.Lights[j].G(sr) / sr.World.Lights[j].PDF(sr);
}
}
}
return (L);
}
public override Vector3 Area_Light_Shade(ShadeRec sr)
{
if (Vector3.Dot(-sr.Normal, sr.Ray.Direction) > 0.0f) //here may be ConcaveSphere not support
return (Radiance * Color);
else
return (Vector3.Zero);
}
public ShadeRec HitObjects(Ray ray)
{
ShadeRec sr = new ShadeRec(this);
float t = 0;
Vector3 normal = Vector3.Zero;
Vector3 local_hit_point = Vector3.Zero;
float tmin = float.MaxValue;
int num_objects = Objects.Count;
for (int j = 0; j < num_objects; j++)
{
if (Objects[j].Hit(ray, ref t, ref sr) && (t < tmin))
{
sr.Hit_an_object = true;
tmin = t;
sr.Material = Objects[j].GetMaterial();
sr.HitPoint = ray.Position + t * ray.Direction;
normal = sr.Normal;
local_hit_point = sr.LocalHitPoint;
}
}
if (sr.Hit_an_object)
{
sr.T = tmin;
sr.Normal = normal;
sr.LocalHitPoint = local_hit_point;
}
return (sr);
}
public override Vector3 Shade(ShadeRec sr)
{
if (Vector3.Dot(-sr.Normal, sr.Ray.Direction) > 0.0f)
return (Radiance * Color);
else
return (Vector3.Zero);
}
public override Vector3 Sample_F(ShadeRec sr, Vector3 wo, ref Vector3 wi, ref float pdf)
{
float ndotwo = Vector3.Dot(sr.Normal, wo);
wi = -wo + 2.0f * sr.Normal * ndotwo;
pdf = MathHelper.Abs(Vector3.Dot(sr.Normal, wi));
return (ReflectionCoefficient * Color);
}
public override bool Hit(Ray ray, ref float tmin, ref ShadeRec sr)
{
if (!bbox.Hit(ray))
return false;
float t = 0;
Vector3 normal = new Vector3(), local_hit_point = Vector3.Zero;
bool hit = false;
tmin = float.MaxValue;
int num_objects = Objects.Count;
for (int j = 0; j < num_objects; j++)
if (Objects[j].Hit(ray, ref t,ref sr) && (t < tmin))
{
hit = true;
tmin = t;
Material = Objects[j].GetMaterial();
normal = sr.Normal;
local_hit_point = sr.LocalHitPoint;
}
if (hit)
{
sr.T = tmin;
sr.Normal = normal;
sr.LocalHitPoint = local_hit_point;
}
return (hit);
}
public override bool Hit(Ray ray, ref float tmin, ref ShadeRec sr)
{
if (!bbox.Hit(ray))
return (false);
float t = Vector3.Dot((center - ray.Position), normal) / Vector3.Dot(ray.Direction, normal);
if (t <= MathHelper.Epsilon)
return (false);
Vector3 p = ray.Position + t * ray.Direction;
float v = center.DistanceSquared(p);
if (v < w_squared && v > i_squared)
{
double phi =MathHelper.Atan2(p.X, p.Z);
if (phi < 0.0)
phi += MathHelper.TwoPI;
if (phi <= max_azimuth && phi >= min_azimuth)
{
tmin = t;
sr.Normal = normal;
sr.LocalHitPoint = p;
return (true);
}
else
return false;
}
else
return (false);
}
public override bool Hit(Ray ray, ref float tmin, ref ShadeRec sr)
{
float t;
Vector3 temp = ray.Position - center;
float a = Vector3.Dot(ray.Direction, ray.Direction);
float b = 2.0f * Vector3.Dot(temp, ray.Direction);
float c = Vector3.Dot(temp, temp) - radius * radius;
float disc = b * b - 4.0f * a * c;
if (disc < 0.0)
return (false);
else
{
float e = MathHelper.Sqrt(disc);
float denom = 2.0f * a;
t = (-b - e) / denom;
if (t > MathHelper.BigEpsilon)
{
tmin = t;
sr.Normal = -(temp + t * ray.Direction) / radius;
sr.LocalHitPoint = ray.Position + t * ray.Direction;
return (true);
}
t = (-b + e) / denom;
if (t > MathHelper.BigEpsilon)
{
tmin = t;
sr.Normal = -(temp + t * ray.Direction) / radius;
sr.LocalHitPoint = ray.Position + t * ray.Direction;
return (true);
}
}
return (false);
}
public override Vector3 GetColor(ShadeRec sr)
{
float x = sr.LocalHitPoint.X;
float y = sr.LocalHitPoint.Y;
float z = sr.LocalHitPoint.Z;
float ph = y;
float phi = MathHelper.Atan2(x, z);
if (phi < 0.0)
phi += 2.0f * MathHelper.PI;
float phi_size = 2.0f * MathHelper.PI / num_horizontal_checkers; // in radians - azimuth angle
float theta_size = h / num_vertical_checkers; // in radians - polar angle
int i_phi = MathHelper.Floor(phi / phi_size);
int i_theta = MathHelper.Floor(ph / theta_size);
float f_phi = phi / phi_size - i_phi;
float f_theta = ph / theta_size - i_theta;
float phi_line_width = 0.5f * vertical_line_width;
float theta_line_width = 0.5f * horizontal_line_width;
bool in_outline = (f_phi < phi_line_width || f_phi > 1.0 - phi_line_width) ||
(f_theta < theta_line_width || f_theta > 1.0 - theta_line_width);
if ((i_phi + i_theta) % 2 == 0)
{
if (!in_outline)
return (color1);
}
else
{
if (!in_outline)
return (color2);
}
return (line_color);
}
internal static ShadeRec trace(Tracer tr, Ray ray)
{
ShadeRec sr = new ShadeRec(tr.World);
float t = 0;
Vector3 normal = Vector3.Zero;
Vector3 local_hit_point = Vector3.Zero;
float tmin = float.MaxValue;
int num_objects = tr.World.Objects.Count;
for (int j = 0; j < num_objects; j++)
if (tr.World.Objects[j].Hit(ray, ref t, ref sr) && (t < tmin))
{
sr.Hit_an_object = true;
tmin = t;
sr.Material = tr.World.Objects[j].Material;
sr.HitPoint = ray.Position + t * ray.Direction;
normal = sr.Normal;
local_hit_point = sr.LocalHitPoint;
}
if (sr.Hit_an_object)
{
sr.T = tmin;
sr.Normal = normal;
sr.LocalHitPoint = local_hit_point;
}
return sr;
}
public override bool Hit(Ray ray, ref float tmin, ref ShadeRec sr)
{
if (box.Hit(ray))
{
return m.Hit(ray, ref tmin, ref sr);
}
return false;
}
public override Vector3 Path_Shade(ShadeRec sr)
{
Vector3 wo = -sr.Ray.Direction;
Vector3 wi = Vector3.Zero;
float pdf = 0;
Vector3 fr = reflective.Sample_F(sr, wo, ref wi, ref pdf);
Ray reflected_ray = new Ray(sr.HitPoint, wi);
return (fr * sr.World.Tracer.TraceRay(reflected_ray, sr.Depth + 1) * (sr.Normal * wi) / pdf);
}
public override Vector3 GetDirection(ShadeRec sr)
{
float r = Radius;
Vector3 new_location = Vector3.Zero;
new_location.X = Location.X + r * (2.0f * MathHelper.RandomFloat() - 1.0f);
new_location.Y = Location.Y + r * (2.0f * MathHelper.RandomFloat() - 1.0f);
new_location.Z = Location.Z + r * (2.0f * MathHelper.RandomFloat() - 1.0f);
return (Vector3.Normalize(new_location - sr.LocalHitPoint));
}
public override Vector3 GetDirection(ShadeRec sr)
{
Vector3 finaldir = Vector3.Zero;
finaldir.X = Direction.X + r * (2.0f * MathHelper.RandomFloat() - 1.0f);
finaldir.Y = Direction.Y + r * (2.0f * MathHelper.RandomFloat() - 1.0f);
finaldir.Z = Direction.Z + r * (2.0f * MathHelper.RandomFloat() - 1.0f);
finaldir.Normalize();
return finaldir;
}
public bool TIR(ShadeRec sr)
{
Vector3 wo = (-sr.Ray.Direction);
float cos_thetai = Vector3.Dot(sr.Normal, wo);
float eta = eta_in / eta_out;
if (cos_thetai < 0.0)
eta = 1.0f / eta;
return (1.0f - (1.0f - cos_thetai * cos_thetai) / (eta * eta) < 0.0f);
}
public override bool Hit(Ray ray, ref float tmin, ref ShadeRec sr)
{
float t;
Vector3 temp = ray.Position - center;
float a = Vector3.Dot(ray.Direction, ray.Direction);
float b = 2.0f * Vector3.Dot(temp, ray.Direction);
float c = Vector3.Dot(temp, temp) - radius * radius;
float disc = b * b - 4.0f * a * c;
if (disc < 0.0)
return (false);
else
{
float e = MathHelper.Sqrt(disc);
float denom = 2.0f * a;
t = (-b - e) / denom; // smaller root
if (t > MathHelper.Epsilon)
{
Vector3 hit = ray.Position + t * ray.Direction - center;
float phi = MathHelper.Atan2(hit.X, hit.Z);
if (phi < 0.0)
phi += MathHelper.TwoPI;
if (hit.Y <= radius * cos_theta_min &&
hit.Y >= radius * cos_theta_max &&
phi >= phi_min && phi <= phi_max)
{
tmin = t;
sr.Normal = (temp + t * ray.Direction) / radius; // points outwards
sr.LocalHitPoint = ray.Position + tmin * ray.Direction;
return (true);
}
}
t = (-b + e) / denom; // larger root
if (t > MathHelper.Epsilon)
{
Vector3 hit = ray.Position + t * ray.Direction - center;
float phi = MathHelper.Atan2(hit.X, hit.Z);
if (phi < 0.0)
phi += MathHelper.TwoPI;
if (hit.Y <= radius * cos_theta_min &&
hit.Y >= radius * cos_theta_max &&
phi >= phi_min && phi <= phi_max)
{
tmin = t;
sr.Normal = (temp + t * ray.Direction) / radius; // points outwards
sr.LocalHitPoint = ray.Position + tmin * ray.Direction;
return (true);
}
}
}
return (false);
}
public override bool InShadow(Ray ray, ShadeRec sr)
{
float t = float.MaxValue;
int num_objects = sr.World.Objects.Count;
float d = Vector3.Distance(Location, (ray.Position));
for (int j = 0; j < num_objects; j++)
if (sr.World.Objects[j].ShadowHit(ray, ref t) && t < d)
return (true);
return (false);
}
public override Vector3 L(ShadeRec sr)
{
if (!DistanceAttenuation)
return (Radiance * Color);
else
{
float d = Vector3.Distance(sr.HitPoint, (Location));
return (Radiance * Color / (d * d));
}
}
public override Vector3 F(ShadeRec sr, Vector3 wo, Vector3 wi)
{
Vector3 L = Vector3.Zero;
float ndotwi = Vector3.Dot(sr.Normal, wi);
Vector3 r = -wi + 2.0f * sr.Normal * ndotwi;
float rdotwo = Vector3.Dot(r, wo);
if (rdotwo > 0.0)
L = ReflectionCoefficient * SpecularTexture.GetColor(sr) * MathHelper.Pow(rdotwo, Exponent);
return (L);
}
public override Vector3 GetDirection(ShadeRec sr)
{
w = sr.Normal;
v = Vector3.Cross(new Vector3(0.0034f, 1, 0.0071f), w);
v.Normalize();
u = Vector3.Cross(v, w);
Vector3 sp = sampler.SampleHemisphere();
wi = sp.X * u + sp.Y * v + sp.Z * w;
return (wi);
}
public override bool InShadow(Ray ray, ShadeRec sr)
{
float t = float.MaxValue; // may be need an initialization
int num_objects = sr.World.Objects.Count;
float d = (Position - ray.Position).Length();
for (int j = 0; j < num_objects; j++)
if (sr.World.Objects[j].ShadowHit(ray, ref t) && t < d)
return (true);
return (false);
}
public override bool Hit(Ray ray, ref float tmin, ref ShadeRec sr)
{
float t;
float ox = ray.Position.X;
float oy = ray.Position.Y;
float oz = ray.Position.Z;
float dx = ray.Direction.X;
float dy = ray.Direction.Y;
float dz = ray.Direction.Z;
float a = dx * dx + dz * dz;
float b = 2.0f * (ox * dx + oz * dz);
float c = ox * ox + oz * oz - radius * radius;
float disc = b * b - 4.0f * a * c;
if (disc < 0.0)
return (false);
else
{
float e = MathHelper.Sqrt(disc);
float denom = 2.0f * a;
t = (-b - e) / denom; // smaller root
if (t > MathHelper.Epsilon)
{
float yhit = oy + t * dy;
if (yhit > y0 && yhit < y1)
{
tmin = t;
sr.Normal = new Vector3((ox + t * dx) * inv_radius, 0.0f, (oz + t * dz) * inv_radius);
sr.Normal.Normalize();
if (Vector3.Dot(-ray.Direction, sr.Normal) < 0.0f)
sr.Normal = -sr.Normal;
sr.LocalHitPoint = ray.Position + tmin * ray.Direction;
return (true);
}
}
t = (-b + e) / denom; // larger root
if (t > MathHelper.Epsilon)
{
float yhit = oy + t * dy;
if (yhit > y0 && yhit < y1)
{
tmin = t;
sr.Normal = new Vector3((ox + t * dx) * inv_radius, 0.0f, (oz + t * dz) * inv_radius);
sr.Normal.Normalize();
if (Vector3.Dot(-ray.Direction, sr.Normal) < 0.0f)
sr.Normal = -sr.Normal;
sr.LocalHitPoint = ray.Position + tmin * ray.Direction;
return (true);
}
}
}
return (false);
}
public override bool InShadow(Ray ray, ShadeRec sr)
{
float t = float.MaxValue;
int num_objects = sr.World.Objects.Count;
for (int j = 0; j < num_objects; j++)
{
if (sr.World.Objects[j].ShadowHit(ray, ref t))
return true;
}
return (false);
}
