RTRay RTRayTracer::genRefractRay(RTVector d, RTVector normal, RTVector closestPoint, double refractionIndex,bool isInside)
{
double n,nt,ni;
if(isInside) {
ni=refractionIndex;
nt=AIR_REFRA;
normal=-normal;
} else {
ni=AIR_REFRA;
nt=refractionIndex;
}
n = ni / nt;
double cosI = -normal.dot(d);
double sinT2 = n * n * (1.0 - cosI * cosI);
if (sinT2 > 1.0) {
exit(EXIT_FAILURE);
}
double cosT = sqrt(1.0 - sinT2);
RTVector refracVector= d * n + normal * (n * cosI - cosT);
double bias = 1e-4;
RTVector ori = (closestPoint-normal)*bias;
// RTVector ori=closestPoint;
RTPoint vertice(ori.getX(),ori.getY(),ori.getZ());
RTRay refracRay(vertice,refracVector);
return refracRay;
}
bool Scene::traceRay(Ray& ray, RenderOption option, float refractiveIndex, int level, Color* acc, HitInfo* hitInfo)
{
if (level > kMaxTraceLevel) {
return false;
}
*acc = kColorBlack;
if (m_rootGroup->hit(ray, hitInfo)) {
Vector3 hitPosition = hitInfo->position;
Vector3 hitNormal = hitInfo->normal;
MaterialRef hitMaterial = hitInfo->material;
if (option & RenderMaterialAmbience) {
Color materialColor;
if (hitMaterial->texture()) {
materialColor = hitMaterial->texture()->texelAt(hitInfo->uv);
} else {
materialColor = hitMaterial->color();
}
*acc += hitMaterial->ambient() * materialColor * (1.0f - hitMaterial->transparency());
}
for (unsigned int i = 0; i < m_lights.size(); i++) {
LightRef light = m_lights[i];
*acc += light->luminanceOfMaterialAt(*hitInfo, this, option) * (1.0f - hitMaterial->transparency());
if (option & RenderReflection) {
if (hitMaterial->reflectivity() > 0.0f && level < kMaxTraceLevel) {
float reflection = 2.0 * ray.direction().dot(hitNormal);
Vector3 reflectionDirection = (ray.direction() - (hitNormal * reflection)).normalize();
Ray reflectedRay(hitPosition, reflectionDirection);
HitInfo reflectionInfo;
Color reflectedColor = kColorBlack;
if (traceRay(reflectedRay, option, refractiveIndex, level + 1, &reflectedColor, &reflectionInfo)) {
reflectedColor = reflectedColor * hitMaterial->reflectivity();
*acc += reflectedColor * (1.0f - hitMaterial->transparency());
}
}
}
if (option & RenderTransparency) {
if (hitMaterial->transparency() > 0.0f && level < kMaxTraceLevel) {
float n = refractiveIndex / hitMaterial->refractiveIndex();
float cosA = -ray.direction().dot(hitNormal);
float cosB = sqrtf(1.0f - n * n * (1 - cosA * cosA));
if (cosB > 0.0f) {
Vector3 refracDirection = (n * ray.direction()) + (n * cosA - cosB) * hitNormal;
Vector3 refracRayOrigin = hitPosition + refracDirection * EPSILON;
Ray refracRay(refracRayOrigin, refracDirection);
HitInfo refracInfo;
Color refracColor = kColorBlack;
if (traceRay(refracRay, option, refractiveIndex, level + 1, &refracColor, &refracInfo)) {
refracColor = refracColor * hitMaterial->transparency();
Color absorbance = hitMaterial->color() * 0.15f * -refracInfo.distance;
Color transparency = Color(expf(absorbance.red), expf(absorbance.green), expf(absorbance.blue));
refracColor = refracColor * transparency;
*acc += refracColor;
}
}
}
}
}
}
return true;
}