/// Evaluate the BRDF for the given pair of directions
Color3f eval(const BSDFQueryRecord &bRec) const {
/* This is a smooth BRDF -- return zero if the measure
is wrong, or when queried for illumination on the backside */
if (bRec.measure != ESolidAngle
|| Frame::cosTheta(bRec.wi) <= 0
|| Frame::cosTheta(bRec.wo) <= 0)
return Color3f(0.0f);
Vector3f wh = (bRec.wi + bRec.wo).normalized();
float cosThetai = Frame::cosTheta(bRec.wi);
float cosThetao = Frame::cosTheta(bRec.wo);
//compute the Beckman term
float D = Microfacet::D(m_alpha, wh) / Frame::cosTheta(wh);
//float D = Warp::squareToBeckmannPdf(wh, m_alpha) / Frame::cosTheta(wh);
//compute the Fresnel term
float F = fresnel(wh.dot(bRec.wi), m_extIOR, m_intIOR);
//compute the geometry term
float G = Microfacet::G(m_alpha, bRec.wi, bRec.wo, wh);
//float G = G1(bRec.wi, wh) * G1(bRec.wo, wh);
return (m_kd * INV_PI) + (m_ks * ((D * F * G)/(4.0f * cosThetai * cosThetao)));
}
MyRGBColor
FresnelReflector::sample_f(const ShadeRec& sr, Vector3D& wr, const Vector3D& wo) const{
float ndotwo = sr.normal * wo;
wr = -wo + 2.0 * sr.normal * ndotwo;
return (fresnel(sr) * white / fabs(sr.normal * wr));
}
Spectrum fDelta(const BSDFQueryRecord &bRec) const {
bool sampleReflection = (bRec.typeMask & EDeltaReflection)
&& (bRec.component == -1 || bRec.component == 0);
bool sampleTransmission = (bRec.typeMask & EDeltaTransmission)
&& (bRec.component == -1 || bRec.component == 1);
bool reflection = bRec.wo.z * bRec.wi.z > 0;
Float fr = fresnel(Frame::cosTheta(bRec.wi), m_extIOR, m_intIOR);
if (sampleReflection && !sampleTransmission && !reflection)
return Spectrum(0.0f);
else if (!sampleReflection && sampleTransmission && reflection)
return Spectrum(0.0f);
if (reflection) {
return m_specularReflectance->getValue(bRec.its) * fr;
} else {
Float etaI = m_extIOR, etaT = m_intIOR;
bool entering = Frame::cosTheta(bRec.wi) > 0.0f;
if (!entering)
std::swap(etaI, etaT);
Float factor = (bRec.quantity == ERadiance)
? (etaI*etaI) / (etaT*etaT) : 1.0f;
return m_specularTransmittance->getValue(bRec.its) * factor * (1 - fr);
}
}
double Clothoid::calcD(double alpha) {
double x, z;
fresnel(sqrt(2 * alpha / PI), x, z);
double d = cos(alpha) * (x)+ (sin(alpha) * z);
return d;
}
void Clothoid::getXY(double s, double a, double b, double c, double& x, double& y) {
double storeX, storeY;
if (a > 0) {
double limit_ = (b + 2 * a * s) / (sqrt(2 * fabs(a) * PI));
fresnel(limit_, storeX, storeY);
x = sqrt(PI / 2 / fabs(a))*((cos(b * b / 4 / a - c))*(storeX)+(sin(b * b / 4 / a - c))*(storeY));
y = sqrt(PI / 2 / fabs(a))*((cos(b * b / 4 / a - c))*(storeY)-(sin(b * b / 4 / a - c))*(storeX));
double x1, y1;
limit_ = (b) / (sqrt(2 * fabs(a) * PI));
fresnel(limit_, storeX, storeY);
x1 = sqrt(PI / 2 / fabs(a))*((cos(b * b / 4 / a - c))*(storeX)+(sin(b * b / 4 / a - c))*(storeY));
y1 = sqrt(PI / 2 / fabs(a))*((cos(b * b / 4 / a - c))*(storeY)-(sin(b * b / 4 / a - c))*(storeX));
x -= x1;
y -= y1;
} else {
a = -a;
double limit_ = (2 * a * s - b) / (sqrt(2 * fabs(a) * PI));
fresnel(limit_, storeX, storeY);
x = sqrt(PI / 2 / fabs(a))*((cos(b * b / 4 / a + c))*(storeX)+(sin(b * b / 4 / a + c))*(storeY));
y = sqrt(PI / 2 / fabs(a))*(-(cos(b * b / 4 / a + c))*(storeY)+(sin(b * b / 4 / a + c))*(storeX));
double x1, y1;
limit_ = (-b) / (sqrt(2 * a * PI));
fresnel(limit_, storeX, storeY);
x1 = sqrt(PI / 2 / fabs(a))*((cos(b * b / 4 / a + c))*(storeX)+(sin(b * b / 4 / a + c))*(storeY));
y1 = sqrt(PI / 2 / fabs(a))*(-(cos(b * b / 4 / a + c))*(storeY)+(sin(b * b / 4 / a + c))*(storeX));
x -= x1;
y -= y1;
}
}
Color trace(Ray& ray, int i){
if(!i) return Color(0,0,0);
Obj* o;
Vector x;
Vector n;
if(firstIntersect(ray, x, n, &o)<0) return La;
Color c=directLight(ray.dir,x,n,o->mat);
if(!o->mat.reflective&&!o->mat.refractive){
double px=(x.x/4+0.5)*phms;
double py=(x.y/4+0.5)*phms;
double u=px-(int)px;
double v=py-(int)py;
Color f=ph2((int)px, (int)py)*(1-u)*(1-v)+
ph2((int)px+1, (int)py)*(u)*(1-v)+
ph2((int)px, (int)py+1)*(1-u)*(v)+
ph2((int)px+1, (int)py+1)*(u)*(v);
c=c+f*(5000./phLim);
}
if(o->mat.reflective) {
Vector refd=reflectDir(ray.dir,n)+x;
Ray ref(x,refd);
if(o->mat.refractive){
bool valid=true;
Vector refrd=refractDir(ray.dir,n,o->mat.n.r,valid);
if(valid){
c=c+fresnel(ray.dir,n,o->mat,false)*trace(ref,i-1);
} else {
c=c+trace(ref,i-1);
}
} else {
c=c+fresnel(ray.dir,n,o->mat,false)*trace(ref,i-1);
}
}
if(o->mat.refractive){
bool valid=true;
Vector refrd=refractDir(ray.dir,n,o->mat.n.r,valid)+x;
if(valid){
Ray refr(x,refrd);
c=c+fresnel(ray.dir,n,o->mat,true)*trace(refr,i-1);
}
}
return c;
}
Spectrum DipoleSubsurfaceIntegrator::Li(const Scene *scene, const Renderer *renderer,
const RayDifferential &ray, const Intersection &isect,
const Sample *sample, RNG &rng, MemoryArena &arena) const {
Spectrum L(0.);
Vector wo = -ray.d;
// Compute emitted light if ray hit an area light source
L += isect.Le(wo);
// Evaluate BSDF at hit point
BSDF *bsdf = isect.GetBSDF(ray, arena);
const Point &p = bsdf->dgShading.p;
const Normal &n = bsdf->dgShading.nn;
Spectrum rho_dr = Spectrum(1.0f);
// Evaluate BSSRDF and possibly compute subsurface scattering
BSSRDF *bssrdf = isect.GetBSSRDF(ray, arena);
if (bssrdf && octree) {
Spectrum sigma_a = bssrdf->sigma_a();
Spectrum sigmap_s = bssrdf->sigma_prime_s();
Spectrum sigmap_t = sigmap_s + sigma_a;
if (!sigmap_t.IsBlack()) {
// Use hierarchical integration to evaluate reflection from dipole model
PBRT_SUBSURFACE_STARTED_OCTREE_LOOKUP(const_cast<Point *>(&p));
DiffusionReflectance Rd(sigma_a, sigmap_s, bssrdf->eta());
Spectrum Mo = octree->Mo(octreeBounds, p, Rd, maxError);
FresnelDielectric fresnel(1.f, bssrdf->eta());
Spectrum Ft = Spectrum(1.f) - fresnel.Evaluate(AbsDot(wo, n));
float Fdt = 1.f - Fdr(bssrdf->eta());
// modulate SSS contribution by rho_dr
//L += (INV_PI * Ft) * (Fdt * Mo);
rho_dr = wet->integrate_BRDF(bsdf, ray.d, 10, BxDFType(BSDF_REFLECTION | BSDF_GLOSSY));
L += (INV_PI * Ft) * (Fdt * Mo) * (Spectrum(1.0f) - rho_dr);
//L += (INV_PI * Ft) * (Fdt * Mo) * (Spectrum(0.0f));
PBRT_SUBSURFACE_FINISHED_OCTREE_LOOKUP();
}
}
L += UniformSampleAllLights(scene, renderer, arena, p, n,
wo, isect.rayEpsilon, ray.time, bsdf, sample, rng, lightSampleOffsets,
bsdfSampleOffsets);
if (ray.depth < maxSpecularDepth) {
// Trace rays for specular reflection and refraction.
//TODO: this has no effect?
L += SpecularReflect(ray, bsdf, rng, isect, renderer, scene,
sample, arena);
L += SpecularTransmit(ray, bsdf, rng, isect,
renderer, scene, sample, arena);
}
return L;
}
Color Fresnel::sample(const IntersectionInfo& info)
{
float eta = ior;
float NdotI = dot(info.normal, info.rayDir);
if (NdotI > 0)
eta = 1.0f / eta;
else
NdotI = -NdotI;
float fr = fresnel(NdotI, eta);
return Color(fr, fr, fr);
}
// for global lighting
MyRGBColor
FresnelReflector::sample_f(const ShadeRec& sr, Vector3D& wr, const Vector3D& wo, float& pdf) const {
float ndotwo = sr.normal * wo;
wr = -wo + 2.0 * sr.normal * ndotwo;
//pdf = sr.normal * wr;
pdf = fabs(sr.normal * wr); // maybe this instead?
// assuming this is correct based on the other sample_f
return(fresnel(sr) * white);
//return (kr * cr);
}
Vec trace(const Ray& r, const int index, const int num_samps) {
// ray-sphere intersection
double t;
if (!intersect(r, t)) return Vec();
// compute the intersection data
const Vec x = r.o + r.d * t, n = (x - sph.p).normalized(), w = -r.d;
// compute Fresnel transmittance at point of emergence
const double T21 = 1.0 - fresnel(w.dot(n), eta);
// integration of the BSSRDF over the surface
unsigned int xi = next_rand(index);
Vec result;
for (int i = 0; i < num_samps; i++) {
// generate a sample
Vec sp, sn, sw;
sample(i, Vec(hal(2, index), hal(3, index), 0.0), sp, sn);
sw = Vec(1, 1, -0.5).normalized();
// directional light source
const double radiance = 8.0*PI;
const double cos_wi_n = sn.dot(sw);
if (cos_wi_n > 0.0) {
// Russian roulette (note that accept_prob can be any value in (0, 1))
const double accept_prob = exp(-(sp - x).len() * min_sigma_tr);
if ((xi / rand_range) < accept_prob) {
const double T12 = 1.0 - fresnel(cos_wi_n, eta);
const double Li_cos = T12 * radiance * cos_wi_n / (samplePDF * accept_prob);
for (int j = 0; j < 3; j++) result[j] += bssrdf(sp, sn, sw, x, n, w, j) * Li_cos;
// reciprocal evaulation with the reciprocity hack
//for (int j = 0; j < 3; j++) result[j] += 0.5 * (bssrdf(sp, sn, sw, x, n, w, j) + bssrdf(x, n, w, sp, sn, sw, j)) * Li_cos;
}
xi = next_rand(xi);
}
}
return T21 * result / (double)num_samps;
}
void shoot(const Color& pow, Ray& ray, int i){
if(i>8) return;
Obj* o;
Vector x;
Vector n;
if(firstIntersect(ray, x, n, &o)<0) return;
if(i&&!o->mat.reflective&&!o->mat.refractive){
if(n*ray.dir<0){
addPhoton(x, pow*(n*ray.dir*-1));
}
return;
}
if(o->mat.reflective) {
Vector refd=reflectDir(ray.dir,n)+x;;
Ray ref(x,refd);
if(o->mat.refractive){
bool valid=true;
Vector refrd=refractDir(ray.dir,n,o->mat.n.r,valid);
if(valid){
shoot(pow*fresnel(ray.dir,n,o->mat,false), ref, i+1);
} else {
shoot(pow, ref, i+1);
}
} else {
shoot(pow*fresnel(ray.dir,n,o->mat,false), ref, i+1);
}
}
if(o->mat.refractive){
bool valid=true;
Vector refrd=refractDir(ray.dir,n,o->mat.n.r,valid)+x;
if(valid){
Ray refr(x,refrd);
shoot(pow*fresnel(ray.dir,n,o->mat,true), refr, i+1);
}
}
}
nex::color fresnel_refraction_btdf::sample(const lumen::sample& sample, const surface& surface,
const nex::vector& wo, nex::vector* wi, float* pdf) const
{
float eta = ni / nt;
*wi = refract(wo, surface.normal, &eta);
*pdf = 1.0f;
// check for total internal reflection
if (*wi == nex::vector(0.0f, 0.0f, 0.0f)) {
return nex::color::black();
}
return (1.0f - fresnel(ni, nt, nex::dot(surface.normal, wo))) *
transmittance / (eta * eta) / std::abs(nex::dot(surface.normal, *wi));
}
Spectrum Lo(const Scene *scene, Sampler *sampler,
const Intersection &its, const Vector &d, int depth) const {
if (!m_ready || m_ssFactor.isZero())
return Spectrum(0.0f);
IsotropicDipoleQuery query(m_zr, m_zv, m_sigmaTr, m_Fdt, its.p);
const Normal &n = its.shFrame.n;
m_octree->execute(query);
if (m_eta == 1.0f) {
return query.getResult() * m_ssFactor * INV_PI;
} else {
Float Ft = 1.0f - fresnel(absDot(n, d));
return query.getResult() * m_ssFactor * INV_PI * (Ft / m_Fdr);
}
}
extern "C" void execute(void *params, BVHShader_functions *func, void *env)
{
BVHShader_surface *surface = (BVHShader_surface*)env;
BVHShader_params *p = (BVHShader_params*)params;
float rayRefract[3];
float rayReflect[3];
BVHColor colorRefraction;
BVHColor colorReflection;
float fresnelFactor;
// Calculate refraction ray
refract(surface->normal, surface->rayInput, rayRefract, p->indexRel);
invert(rayRefract);
normalize(rayRefract);
// Calculate reflection ray
reflect(surface->normal, surface->rayInput, rayReflect);
invert(rayReflect);
normalize(rayReflect);
// Normalize vector
normalize(surface->rayOutput);
// Get fresnel
fresnelFactor = fresnel(surface->normal, surface->rayInput, p->indexRel);
// Calculate reflection and refraction color
if (dotAbs(surface->rayOutput, rayRefract) > 0.9999f)
{
colorRefraction.init(1.0f / dotAbs(surface->rayOutput, surface->normal));
colorReflection.init(0.0f);
}
else if (dotAbs(surface->rayOutput, rayReflect) > 0.9999f)
{
colorRefraction.init(0.0f);
colorReflection.init(1.0f / dotAbs(surface->rayOutput, surface->normal));
}
else
{
colorRefraction.init(0.0f);
colorReflection.init(0.0f);
}
surface->color = p->color * (colorRefraction * (1.0f - fresnelFactor) + colorReflection * fresnelFactor);
surface->emission.init(0.0f);
}
Color3f sample(BSDFQueryRecord &bRec, const Point2f &sample) const {
bRec.measure = EDiscrete;
//check if your are inside or not
//compute the angle between the normal and the incoming direction
float theta1 = Frame::cosTheta(bRec.wi);
float fresnelTerm = fresnel(theta1, m_extIOR, m_intIOR);
//check if entering or leaving
bRec.entering = (theta1 > 0);
float et = m_extIOR;
float ei = m_intIOR;
Vector3f n = Vector3f(0.0, 0.0, 1.0);
if(!bRec.entering) {
std::swap(ei, et);
n(2) = -1.0;
}
// check you should a reflection or refraction
if(sample(0) < fresnelTerm) {
//mirror like reflection
bRec.wo = Vector3f(
-bRec.wi.x(),
-bRec.wi.y(),
bRec.wi.z()
);
bRec.eta = 1.0f;
} else {
float snellsTerm = et / ei;
float wdotn = bRec.wi.dot(n);
Vector3f fstPart = (bRec.wi - (wdotn) * n);
float srqtTerm = std::sqrt(1.0f - snellsTerm * snellsTerm * (1.0f - wdotn * wdotn));
bRec.wo = - snellsTerm * fstPart - n * srqtTerm;
bRec.eta = bRec.entering? m_intIOR / m_extIOR : m_extIOR / m_intIOR;
}
return Color3f(1.0f);
}
Float pdfDelta(const BSDFQueryRecord &bRec) const {
bool sampleReflection = (bRec.typeMask & EDeltaReflection)
&& (bRec.component == -1 || bRec.component == 0);
bool sampleTransmission = (bRec.typeMask & EDeltaTransmission)
&& (bRec.component == -1 || bRec.component == 1);
bool reflection = bRec.wo.z * bRec.wi.z > 0;
Float result = 0.0f;
if (sampleTransmission && sampleReflection) {
Float fr = fresnel(Frame::cosTheta(bRec.wi), m_extIOR, m_intIOR);
result = reflection ? fr : (1-fr);
} else if (sampleReflection) {
result = reflection ? 1.0f : 0.0f;
} else if (sampleTransmission) {
result = reflection ? 0.0f : 1.0f;
}
return result * std::abs(Frame::cosTheta(bRec.wo));
}
/**
* Simple program that starts our raytracer
*/
int main(int argc, char *argv[]) {
try {
RayTracer* rt;
Timer t;
rt = new RayTracer(800, 600);
std::shared_ptr<SceneObjectEffect> color(new ColorEffect(glm::vec3(0.0, 1.0, 0.0)));
std::shared_ptr<SceneObjectEffect> phong(new PhongEffect(glm::vec3(0.0, 0.0, 10.0)));
std::shared_ptr<SceneObjectEffect> steel(new SteelEffect());
std::shared_ptr<SceneObjectEffect> fresnel(new FresnelEffect());
std::shared_ptr<SceneObject> s1(new Sphere(glm::vec3(-3.0f, 0.0f, 6.0f), 2.0f, steel));
rt->addSceneObject(s1);
std::shared_ptr<SceneObject> s2(new Sphere(glm::vec3(3.0f, 0.0f, 3.0f), 2.0f, fresnel));
rt->addSceneObject(s2);
std::shared_ptr<SceneObject> s3(new Sphere(glm::vec3(0.0f, 3.0f, 9.0f), 2.0f, steel));
rt->addSceneObject(s3);
std::string path = "cubemaps/SaintLazarusChurch3/";
std::shared_ptr<SceneObject> cubeMap(new CubeMap(path + "posx.jpg", path + "negx.jpg",
path + "posy.jpg", path + "negy.jpg",
path + "posz.jpg", path + "negz.jpg"));
rt->addSceneObject(cubeMap);
std::shared_ptr<SceneObject> triangle(new Triangle(glm::vec3(0.0f, 2.0f, -1.0f),
glm::vec3(-2.0f, -2.0f, -1.0f), glm::vec3(2.0f, -2.0f, 0.0f), steel));
rt->addSceneObject(triangle);
t.restart();
rt->render();
double elapsed = t.elapsed();
std::cout << "Computed in " << elapsed << " seconds" << std::endl;
rt->save("test", "bmp"); //We want to write out bmp's to get proper bit-maps (jpeg encoding is lossy)
delete rt;
} catch (std::exception &e) {
std::string err = e.what();
std::cout << err.c_str() << std::endl;
return -1;
}
return 0;
}
const BSDF *MetalMaterial::GetBSDF(const DifferentialGeometry &i_dg, size_t i_triangle_index, MemoryPool &i_pool) const
{
BSDF *p_bsdf = new ( i_pool.Alloc(sizeof(BSDF)) ) BSDF(i_dg);
SpectrumCoef_d r, a;
if (mp_refractive_index && mp_absorption)
{
r = mp_refractive_index->Evaluate(i_dg, i_triangle_index);
a = mp_absorption->Evaluate(i_dg, i_triangle_index);
}
else
{
ASSERT(mp_reflectance);
SpectrumCoef_d reflectance = mp_reflectance->Evaluate(i_dg, i_triangle_index);
reflectance.Clamp(0.0, 1.0);
ApproximateFresnelParameters(reflectance, r, a);
}
FresnelConductor fresnel(r, a);
BxDF *p_bxdf;
if (mp_roughness)
{
typedef Microfacet<FresnelConductor,BlinnDistribution> BlinnMicrofacetMetal;
double roughness = MathRoutines::Clamp(mp_roughness->Evaluate(i_dg, i_triangle_index), 0.001, 1.0);
BlinnDistribution blinn(1.0/roughness);
p_bxdf = new ( i_pool.Alloc(sizeof(BlinnMicrofacetMetal)) ) BlinnMicrofacetMetal(SpectrumCoef_d(1.0), fresnel, blinn);
}
else
{
ASSERT(mp_u_roughness && mp_v_roughness);
typedef Microfacet<FresnelConductor,AnisotropicDistribution> AnisotropicMicrofacetMetal;
double u_roughness = MathRoutines::Clamp(mp_u_roughness->Evaluate(i_dg, i_triangle_index), 0.001, 1.0);
double v_roughness = MathRoutines::Clamp(mp_v_roughness->Evaluate(i_dg, i_triangle_index), 0.001, 1.0);
AnisotropicDistribution anisotropic(1.0/u_roughness, 1.0/v_roughness);
p_bxdf = new ( i_pool.Alloc(sizeof(AnisotropicMicrofacetMetal)) ) AnisotropicMicrofacetMetal(SpectrumCoef_d(1.0), fresnel, anisotropic);
}
p_bsdf->AddBxDF(p_bxdf);
return p_bsdf;
}
bool refractRay(const Vec3& origin, const Vec3&incident_dir, const Vec3& normal, const float rei[],
Vec3& refract_dir, float& ref_weight)
{
float eta = rei[0] / rei[1];
float c1 = normal.dot(incident_dir), c2 = 1 - eta*eta*(1 - c1*c1);
if (c2<0)
{
ref_weight = 1.0f;
return false;
}
Vec3 v_nor = normal;
if (c1<0.0f)
c1 = -c1;
else
v_nor *= -1;
refract_dir = eta*incident_dir + (eta*c1 - sqrt(c2))*v_nor;
fresnel(c1, fabs(refract_dir.dot(normal)), rei, ref_weight);
return true;
}
RGBColor
FresnelTransmitter::sample_f(const ShadeRec& sr, const Vector3D& wo, Vector3D& wt) const {
Normal n(sr.normal);
float cos_thetai = n * wo;
float eta = eta_in / eta_out;//ior;
if (cos_thetai < 0.0) { // transmitted ray is outside
cos_thetai = -cos_thetai;
n = -n; // reverse direction of normal
eta = 1.0 / eta; // invert ior
}
float temp = 1.0 - (1.0 - cos_thetai * cos_thetai) / (eta * eta);
float cos_theta2 = sqrt(temp);
wt = -wo / eta - (cos_theta2 - cos_thetai / eta) * n;
return (fresnel(sr) / (eta * eta) * white / fabs(sr.normal * wt));
}
static unsigned int ray_color(const point3 e, double t,
const point3 d,
idx_stack *stk,
const rectangular_node rectangulars,
const sphere_node spheres,
const light_node lights,
color object_color, int bounces_left)
{
rectangular_node hit_rec = NULL, light_hit_rec = NULL;
sphere_node hit_sphere = NULL, light_hit_sphere = NULL;
double diffuse, specular;
point3 l, _l, r, rr;
object_fill fill;
color reflection_part;
color refraction_part;
/* might be a reflection ray, so check how many times we've bounced */
if (bounces_left == 0) {
SET_COLOR(object_color, 0.0, 0.0, 0.0);
return 0;
}
/* check for intersection with a sphere or a rectangular */
intersection ip= ray_hit_object(e, d, t, MAX_DISTANCE, rectangulars,
&hit_rec, spheres, &hit_sphere);
if (!hit_rec && !hit_sphere)
return 0;
/* pick the fill of the object that was hit */
fill = hit_rec ?
hit_rec->element.rectangular_fill :
hit_sphere->element.sphere_fill;
void *hit_obj = hit_rec ? (void *) hit_rec : (void *) hit_sphere;
/* assume it is a shadow */
SET_COLOR(object_color, 0.0, 0.0, 0.0);
for (light_node light = lights; light; light = light->next) {
/* calculate the intersection vector pointing at the light */
subtract_vector(ip.point, light->element.position, l);
multiply_vector(l, -1, _l);
normalize(_l);
/* check for intersection with an object. use ignore_me
* because we don't care about this normal
*/
ray_hit_object(ip.point, _l, MIN_DISTANCE, length(l),
rectangulars, &light_hit_rec,
spheres, &light_hit_sphere);
/* the light was not block by itself(lit object) */
if (light_hit_rec || light_hit_sphere)
continue;
compute_specular_diffuse(&diffuse, &specular, d, l,
ip.normal, fill.phong_power);
localColor(object_color, light->element.light_color,
diffuse, specular, &fill);
}
reflection(r, d, ip.normal);
double idx = idx_stack_top(stk).idx, idx_pass = fill.index_of_refraction;
if (idx_stack_top(stk).obj == hit_obj) {
idx_stack_pop(stk);
idx_pass = idx_stack_top(stk).idx;
} else {
idx_stack_element e = { .obj = hit_obj,
.idx = fill.index_of_refraction
};
idx_stack_push(stk, e);
}
refraction(rr, d, ip.normal, idx, idx_pass);
double R = (fill.T > 0.1) ?
fresnel(d, rr, ip.normal, idx, idx_pass) :
1.0;
/* totalColor = localColor +
mix((1-fill.Kd) * fill.R * reflection, T * refraction, R)
*/
if (fill.R > 0) {
/* if we hit something, add the color */
int old_top = stk->top;
if (ray_color(ip.point, MIN_DISTANCE, r, stk, rectangulars, spheres,
lights, reflection_part,
bounces_left - 1)) {
multiply_vector(reflection_part, R * (1.0 - fill.Kd) * fill.R,
reflection_part);
add_vector(object_color, reflection_part,
object_color);
}
stk->top = old_top;
}
/* calculate refraction ray */
if ((length(rr) > 0.0) && (fill.T > 0.0) &&
(fill.index_of_refraction > 0.0)) {
normalize(rr);
if (ray_color(ip.point, MIN_DISTANCE, rr, stk,rectangulars, spheres,
lights, refraction_part,
bounces_left - 1)) {
multiply_vector(refraction_part, (1 - R) * fill.T,
refraction_part);
add_vector(object_color, refraction_part,
object_color);
}
}
protect_color_overflow(object_color);
return 1;
}
/* @param background_color this is not ambient light */
void raytracing(void* args)
{
arg *data = (arg*) args;
point3 u, v, w, d;
color object_color = { 0.0, 0.0, 0.0 };
const viewpoint *view = (*data).View;
color back = { 0.0 , 0.1 , 0.1 };
uint8_t *pixels = data->pixels;
int start_j,end_j;
/* Separate to count the pixels */
if(pthread_equal(pthread_self(),THREAD[0])) {
start_j = 0;
end_j = 128;
} else if(pthread_equal(pthread_self(),THREAD[1])) {
start_j = 128;
end_j = 256;
} else if(pthread_equal(pthread_self(),THREAD[2])) {
start_j = 256;
end_j = 384;
} else if(pthread_equal(pthread_self(),THREAD[3])) {
start_j = 384;
end_j = 512;
}
/* calculate u, v, w */
calculateBasisVectors(u, v, w, view);
idx_stack stk;
int factor = sqrt(SAMPLES);
#pragma omp parallel for num_threads(64) \
private(stk), private(d), \
private(object_color)
for (int j = start_j ; j < end_j; j++) {
for (int i = 0 ; i < (*data).row; i++) {
double r = 0, g = 0, b = 0;
/* MSAA */
for (int s = 0; s < SAMPLES; s++) {
idx_stack_init(&stk);
rayConstruction(d, u, v, w,
i * factor + s / factor,
j * factor + s % factor,
view,
(*data).row * factor, (*data).col * factor);
if (ray_color(view->vrp, 0.0, d, &stk,(*data).rectangulars,
(*data).spheres, (*data).lights, object_color,
MAX_REFLECTION_BOUNCES)) {
r += object_color[0];
g += object_color[1];
b += object_color[2];
} else {
r += back[0];
g += back[1];
b += back[2];
}
pixels[((i + (j * (*data).row)) * 3) + 0] = r * 255 / SAMPLES;
pixels[((i + (j * (*data).row)) * 3) + 1] = g * 255 / SAMPLES;
pixels[((i + (j * (*data).row)) * 3) + 2] = b * 255 / SAMPLES;
}
}
}
}
void fg(real_t x, real_t *f, real_t *g)
{
void fresnel(real_t, real_t *, real_t *);
real_t absx,c,s,c1,s1,a,xinv,x3inv,c4,p,q;
absx=fabs(x);
if (absx <= 1.6) {
fresnel(x,&c,&s);
a=x*x*1.57079632679490;
c1=cos(a);
s1=sin(a);
a = (x < 0.0) ? -0.5 : 0.5;
p=a-c;
q=a-s;
*f = q*c1-p*s1;
*g = p*c1+q*s1;
} else if (absx <= 1.9) {
xinv=1.0/x;
a=xinv*xinv;
x3inv=a*xinv;
c4=a*a;
p=(((1.35304235540388e1*c4+6.98534261601021e1)*c4+
4.80340655577925e1)*c4+8.03588122803942e0)*c4+
3.18309268504906e-1;
q=(((6.55630640083916e1*c4+2.49561993805172e2)*c4+
1.57611005580123e2)*c4+2.55491618435795e1)*c4+1.0;
*f = xinv*p/q;
p=((((2.05421432498501e1*c4+1.96232037971663e2)*c4+
1.99182818678903e2)*c4+5.31122813480989e1)*c4+
4.44533827550512e0)*c4+1.01320618810275e-1;
q=((((1.01379483396003e3*c4+3.48112147856545e3)*c4+
2.54473133181822e3)*c4+5.83590575716429e2)*c4+
4.53925019673689e1)*c4+1.0;
*g = x3inv*p/q;
} else if (absx <= 2.4) {
xinv=1.0/x;
a=xinv*xinv;
x3inv=a*xinv;
c4=a*a;
p=((((7.17703249365140e2*c4+3.09145161574430e3)*c4+
1.93007640786716e3)*c4+3.39837134926984e2)*c4+
1.95883941021969e1)*c4+3.18309881822017e-1;
q=((((3.36121699180551e3*c4+1.09334248988809e4)*c4+
6.33747155851144e3)*c4+1.08535067500650e3)*c4+
6.18427138172887e1)*c4+1.0;
*f = xinv*p/q;
p=((((3.13330163068756e2*c4+1.59268006085354e3)*c4+
9.08311749529594e2)*c4+1.40959617911316e2)*c4+
7.11205001789783e0)*c4+1.01321161761805e-1;
q=((((1.15149832376261e4*c4+2.41315567213370e4)*c4+
1.06729678030581e4)*c4+1.49051922797329e3)*c4+
7.17128596939302e1)*c4+1.0;
*g = x3inv*p/q;
} else {
xinv=1.0/x;
a=xinv*xinv;
x3inv=a*xinv;
c4=a*a;
p=((((2.61294753225142e4*c4+6.13547113614700e4)*c4+
1.34922028171857e4)*c4+8.16343401784375e2)*c4+
1.64797712841246e1)*c4+9.67546032967090e-2;
q=((((1.37012364817226e6*c4+1.00105478900791e6)*c4+
1.65946462621853e5)*c4+9.01827596231524e3)*c4+
1.73871690673649e2)*c4+1.0;
*f = (c4*(-p)/q+0.318309886183791)*xinv;
p=(((((1.72590224654837e6*c4+6.66907061668636e6)*c4+
1.77758950838030e6)*c4+1.35678867813756e5)*c4+
3.87754141746378e3)*c4+4.31710157823358e1)*c4+
1.53989733819769e-1;
q=(((((1.40622441123580e8*c4+9.38695862531635e7)*c4+
1.62095600500232e7)*c4+1.02878693056688e6)*c4+
2.69183180396243e4)*c4+2.86733194975899e2)*c4+1.0;
*g = (c4*(-p)/q+0.101321183642338)*x3inv;
}
}
cv::Mat HologramDecoder::decode_hologram( cv::Mat hologram, float z, float lambda, float dx, float dy ) {
return fresnel( hologram, dx, dy, lambda * z, lambda );
}
static unsigned int ray_color(const point3 e, double t,
const point3 d,
idx_stack *stk,
const rectangular_node rectangulars,
const sphere_node spheres,
const light_node lights,
color object_color, int bounces_left)
{
rectangular_node hit_rec = NULL, light_hit_rec = NULL;
sphere_node hit_sphere = NULL, light_hit_sphere = NULL;
double diffuse, specular;
point3 l, _l, r, rr;
object_fill fill;
color reflection_part;
color refraction_part;
/* might be a reflection ray, so check how many times we've bounced */
if (bounces_left == 0) {
SET_COLOR(object_color, 0.0, 0.0, 0.0);
return 0;
}
/* check for intersection with a sphere or a rectangular */
intersection ip= ray_hit_object(e, d, t, MAX_DISTANCE, rectangulars,
&hit_rec, spheres, &hit_sphere);
if (!hit_rec && !hit_sphere)
return 0;
/* pick the fill of the object that was hit */
fill = hit_rec ?
hit_rec->element.rectangular_fill :
hit_sphere->element.sphere_fill;
void *hit_obj = hit_rec ? (void *) hit_rec : (void *) hit_sphere;
/* assume it is a shadow */
SET_COLOR(object_color, 0.0, 0.0, 0.0);
for (light_node light = lights; light; light = light->next) {
/* calculate the intersection vector pointing at the light */
subtract_vector(ip.point, light->element.position, l);
multiply_vector(l, -1, _l);
normalize(_l);
/* check for intersection with an object. use ignore_me
* because we don't care about this normal
*/
ray_hit_object(ip.point, _l, MIN_DISTANCE, length(l),
rectangulars, &light_hit_rec,
spheres, &light_hit_sphere);
/* the light was not block by itself(lit object) */
if (light_hit_rec || light_hit_sphere)
continue;
compute_specular_diffuse(&diffuse, &specular, d, l,
ip.normal, fill.phong_power);
localColor(object_color, light->element.light_color,
diffuse, specular, &fill);
}
reflection(r, d, ip.normal);
double idx = idx_stack_top(stk).idx, idx_pass = fill.index_of_refraction;
if (idx_stack_top(stk).obj == hit_obj) {
idx_stack_pop(stk);
idx_pass = idx_stack_top(stk).idx;
} else {
idx_stack_element e = { .obj = hit_obj,
.idx = fill.index_of_refraction
};
idx_stack_push(stk, e);
}
refraction(rr, d, ip.normal, idx, idx_pass);
double R = (fill.T > 0.1) ?
fresnel(d, rr, ip.normal, idx, idx_pass) :
1.0;
/* totalColor = localColor +
mix((1-fill.Kd) * fill.R * reflection, T * refraction, R)
*/
if (fill.R > 0) {
/* if we hit something, add the color */
int old_top = stk->top;
if (ray_color(ip.point, MIN_DISTANCE, r, stk, rectangulars, spheres,
lights, reflection_part,
bounces_left - 1)) {
multiply_vector(reflection_part, R * (1.0 - fill.Kd) * fill.R,
reflection_part);
add_vector(object_color, reflection_part,
object_color);
}
stk->top = old_top;
}
/* calculate refraction ray */
if ((length(rr) > 0.0) && (fill.T > 0.0) &&
(fill.index_of_refraction > 0.0)) {
normalize(rr);
if (ray_color(ip.point, MIN_DISTANCE, rr, stk,rectangulars, spheres,
lights, refraction_part,
bounces_left - 1)) {
multiply_vector(refraction_part, (1 - R) * fill.T,
refraction_part);
add_vector(object_color, refraction_part,
object_color);
}
}
protect_color_overflow(object_color);
return 1;
}
static void *parallel (void* range1)
{
Thread_range *range = (Thread_range *)range1;
point3 d;
idx_stack stk;
color object_color = { 0.0, 0.0, 0.0 };
for (int j = range->height1; j < range->height2; j++) {
for (int i = 0; i < range->ptr->width; i++) {
double r = 0, g = 0, b = 0;
/* MSAA */
for (int s = 0; s < SAMPLES; s++) {
idx_stack_init(&stk);
rayConstruction(d, range->ptr->u,
range->ptr->v, range->ptr->w,
i * range->ptr->factor + s / range->ptr->factor,
j * range->ptr->factor + s % range->ptr->factor,
range->ptr->view,
range->ptr->width * range->ptr->factor,
range->ptr->height * range->ptr->factor);
if (ray_color(range->ptr->view->vrp, 0.0, d,
&(stk), range->ptr->rectangulars,
range->ptr->spheres,
range->ptr->lights, object_color,
MAX_REFLECTION_BOUNCES)) {
r += object_color[0];
g += object_color[1];
b += object_color[2];
} else {
r += range->ptr->background_color[0];
g += range->ptr->background_color[1];
b += range->ptr->background_color[2];
}
range->ptr->pixels[((i + (j * range->ptr->width)) * 3) + 0] = r * 255 / SAMPLES;
range->ptr->pixels[((i + (j * range->ptr->width)) * 3) + 1] = g * 255 / SAMPLES;
range->ptr->pixels[((i + (j * range->ptr->width)) * 3) + 2] = b * 255 / SAMPLES;
}
}
}
return NULL;
}
