Tcolor TrayTracer::radianceWithExplicitLight(Tray ray,int reflectLevel)
{
if(reflectLevel <= 0)
return Tcolor(0,0,0);
Tcolor finalColor(0,0,0);
auto result = scene()->intersect(ray);
if (result.geometry()) {
auto material = result.geometry ()->material ();
if(!material) return finalColor;
Tcolor selfColor = material->sampleSelfColor ();
//**********Emission.
auto emissionColor = selfColor*material->emission ();
//reflect
Tcolor reflectColor;
auto allLights = scene()->getLightList();
for(int i =0;i<allLights.size ();i++)
{
TexplicitLight * light = allLights[i];
if(!light->isVisible (result.pos (),scene())) continue;
//get the irradiance from the explicit light source.
auto lightDir = light->getDir (result.pos ());
auto lightRadiance = light->getIrradiance (result.pos (),result.normal (),scene());
reflectColor += lightRadiance * material->BRDF (-ray.direction (),-lightDir,result.normal ());
}
//ideal specular radiance from other object.
if(material->reflectiveness () > 0)
{
// get the ideal specular ray.
auto reflectVec = reflect(ray.direction (),result.normal ());
auto reflectRay = Tray(result.pos (),reflectVec);
auto idealSpecularRadiance = radianceWithExplicitLight(reflectRay,reflectLevel - 1);
reflectColor +=idealSpecularRadiance * material->BRDF (-ray.direction (),reflectVec,result.normal ());
}
//render euqation.
finalColor = emissionColor+ selfColor*reflectColor*material->reflectiveness ();
}
return finalColor;
}
Vector3
RefractiveInterface::shade(const Ray& ray, const HitInfo& hit, const Scene& scene, const bool& isFront) const
{
Ray rayLight;
HitInfo hitLight;
Vector3 L = Vector3(0.0f, 0.0f, 0.0f);
const Vector3 viewDir = -ray.d; // d is a unit vector
const PointLights *plightlist = scene.pointLights();
// loop over all of the POINT lights
PointLights::const_iterator plightIter;
for (plightIter = plightlist->begin(); plightIter != plightlist->end(); plightIter++)
{
PointLight* pLight = *plightIter;
Vector3 l = pLight->position() - hit.P;
rayLight.o = hit.P;
rayLight.d = l.normalized();
Vector3 brdf = BRDF(rayLight.d, hit.N, -ray.d, isFront);
if (brdf == 0) continue;
if (scene.trace(hitLight, rayLight, 0.0001, l.length())) continue;
// the inverse-squared falloff
float falloff = l.length2();
float nDotL = fabs(dot(hit.N, l));
Vector3 result = pLight->color();
L += nDotL / falloff * pLight->wattage() *brdf * result;
}
const AreaLights *alightlist = scene.areaLights();
// loop over all of the lights
AreaLights::const_iterator alightIter;
for (alightIter = alightlist->begin(); alightIter != alightlist->end(); alightIter++)
{
AreaLight* aLight = *alightIter;
vec3pdf vp = aLight->randPt();
Vector3 l = vp.v - hit.P; // shoot a shadow ray to a random point on the area light
rayLight.o = hit.P;
rayLight.d = l.normalized();
Vector3 brdf = BRDF(rayLight.d, hit.N, -ray.d, isFront);
if (brdf == 0) continue;
// if the shadow ray hits the "backside of the light" continue to the next area light
if (!aLight->intersect(hitLight, rayLight)){
continue;
}
// if the shadow ray is occluded by another (hence the "skip") object continue the next light
if (scene.trace(hitLight, rayLight, aLight, 0.0001, l.length())){
continue;
}
// the inverse-squared falloff
float falloff = l.length2();
float nDotL = fabs(dot(hit.N, l));
Vector3 result = aLight->color();
L += std::max(0.0f, dot(hitLight.N, -l))* 0.0f, nDotL / falloff*
aLight->wattage() / aLight->area() *brdf * result / (vp.p);
}
// add the ambient component
L += m_ka;
return L;
}
Tcolor TrayTracer::radiancePathTracer(Tray ray, int reflectLevel)
{
if(reflectLevel <=0) return Tcolor(0,0,0);
auto result = scene()->intersect(ray);
if (result.geometry()) {
auto material = result.geometry ()->material ();
auto emissionColor = material->sampleSelfColor () * material->emission ();
auto reflectColor = Tcolor(0,0,0);
switch(material->getType ())
{
case Tmaterial::MaterialType::Mirror://ideal specular object.
{
auto reflectVec = reflect(ray.direction (),result.normal ());
auto reflectRay = Tray(result.pos (),reflectVec);
auto idealSpecularRadiance = radiancePathTracer(reflectRay,reflectLevel - 1);
reflectColor +=idealSpecularRadiance * material->BRDF (-ray.direction (),reflectVec,result.normal ());
}
break;
case Tmaterial::MaterialType::Light://ideal emission object.
{
reflectColor = Tcolor(0,0,0);
}
break;
case Tmaterial::MaterialType::BlinnPhong:
{
}
break;
case Tmaterial::MaterialType::Diffuse:
{
Tvector nl;
if(Tvector::dotProduct (result.normal (),ray.direction ())<0)
{
nl = result.normal ();
}else
{
nl = result.normal ().negatived();
}
double r1=2*TbaseMath::PI*TbaseMath::randF ();
double r2=TbaseMath::randF ();
double r2s=sqrt(r2);
Tvector w=nl;
Tvector u;
if(fabs(w.x())>0.1)
{
u = Tvector(0,1,0);
}else
{
u = Tvector(1,0,0);
}
u = Tvector::crossProduct (u,w);
u.normalize ();
Tvector v=Tvector::crossProduct (w,u);
Tvector dir = (u*cos(r1)*r2s + v*sin(r1)*r2s + w*sqrt(1-r2)).normalized();
reflectColor = radiancePathTracer(Tray(result.pos (),dir),reflectLevel - 1);
}
break;
}
return emissionColor + material->selfColor () * reflectColor * material->reflectiveness ();
}
return Tcolor(0,0,0);
}
