// For Shading Purposes
void RT_shade(Ray* ray, int depth) {
if (depth <= MAX_DEPTH){
// Color Coefficients
Vector4* diffuseCoeff = new Vector4();
Vector4* specularCoeff = new Vector4();
double shininess;
// Diffuse and Specular Terms
double diffuseTerm[3] = {0.0, 0.0, 0.0};
double specularTerm[3] = {0.0, 0.0, 0.0};
if (ray->intersectedObject == SPHERE) {
diffuseCoeff->ReInitialize(spheres[ray->intersectID].color_diffuse);
specularCoeff->ReInitialize(spheres[ray->intersectID].color_specular);
shininess = spheres[ray->intersectID].shininess;
}
else if (ray->intersectedObject == TRIANGLE) {
// Interpolate diffuse and specular coefficients
double alpha, beta;
ObtainIntermediateTriangleIntersection(ray->intersectID, ray->intersectPoint, &alpha, &beta);
diffuseCoeff->ReInitialize();
InterpolateTriangleProperty(triangles[ray->intersectID].v[0].color_diffuse,
triangles[ray->intersectID].v[1].color_diffuse,
triangles[ray->intersectID].v[2].color_diffuse,
alpha, beta, diffuseCoeff, false);
specularCoeff->ReInitialize();
InterpolateTriangleProperty(triangles[ray->intersectID].v[0].color_specular,
triangles[ray->intersectID].v[1].color_specular,
triangles[ray->intersectID].v[2].color_specular,
alpha, beta, specularCoeff, false);
// Interpolate shininess
if (alpha > 0) {
double intermediateShininess = beta * triangles[ray->intersectID].v[2].shininess
+ (1 - beta) * triangles[ray->intersectID].v[1].shininess;
shininess = ((alpha - 1) * triangles[ray->intersectID].v[0].shininess
+ intermediateShininess) / alpha;
}
else {
shininess = triangles[ray->intersectID].v[0].shininess;
}
}
// Boundary Checking
assert(diffuseCoeff->HasNonNegativeEntries());
assert(!diffuseCoeff->HasGreaterThanOneEntries());
assert(specularCoeff->HasNonNegativeEntries());
assert(!specularCoeff->HasGreaterThanOneEntries());
assert(shininess >= 0);
// Normal Vector: N
Vector4* N = new Vector4(ray->normal);
N->ConvertToUnitVector();
// Viewer Direction: V = ray->intersectedPoint - ray->source = -ray->dir
Vector4* V = new Vector4(ray->dir);
V->Scale(-1);
V->ConvertToUnitVector();
int dontCheckObject = NONE;
int dontCheckObjectID = NONE;
if (ray->intersectedObject == TRIANGLE) {
dontCheckObject = ray->intersectedObject;
dontCheckObjectID = ray->intersectID;
}
unsigned int i;
for (i = 0; i < num_lights; i++) {
// Shoot a ray in the direction of the light
Vector4* lightPos = new Vector4(lights[i].position);
Ray* checkShadow = new Ray(ray->intersectPoint, lightPos);
bool shadow = false;
double nearestTIntersect = FindNearestTIntersection(checkShadow,dontCheckObject,dontCheckObjectID);
double point2LightDistance = FindDistanceOfIntersectedPointWithLight(ray,i);
if (nearestTIntersect != INFINITY
&& nearestTIntersect< point2LightDistance)
{
shadow = true;
}
// Point to Light Vector: L = light_pos - intersectedPoint
Vector4* L = new Vector4(lights[i].position);
L->Subtraction(ray->intersectPoint);
L->ConvertToUnitVector();
// Reflected Ray: R = 2(N.L)N - L
Vector4* R = new Vector4(ray->normal);
R->Scale(2 * N->DotProduct(L));
R->Subtraction(L);
R->ConvertToUnitVector();
// Dot Product of N and L: NL
double NL = N->DotProduct(L);
if (NL < 0) {
NL = 0;
}
// Dot Product of R and V: RV
double RV = R->DotProduct(V);
if (RV < 0) {
RV = 0;
}
assert(NL <= 1 && RV <= 1);
double attenuationTerm = depth==1?1:1;
if (!shadow) {
unsigned int j;
for (j = 0; j < 3; j++) {
diffuseTerm[j] += attenuationTerm * lights[i].color[j] * diffuseCoeff->vector[j] * NL;
specularTerm[j] += attenuationTerm * lights[i].color[j] * specularCoeff->vector[j] * pow(RV, shininess);
}
}
delete(L);
delete(R);
delete(lightPos);
delete(checkShadow);
}
// Adding diffused light
Vector4* diffusedColor = new Vector4(diffuseTerm);
// //For Debugging Purposes
// if(ray->intersectedObject == SPHERE){
// ray->color->Display();
// diffusedColor->Display();
// cout<<"................................................."<<endl;
// }
ray->color->Addition(diffusedColor);
delete(diffusedColor);
// Adding specular light
Vector4* specularColor = new Vector4(specularTerm);
ray->color->Addition(specularColor);
delete(specularColor);
//R = 2*(NI)N - I ; N = N; I = V = ray->source - ray->IntersectPoint
Vector4* R_ = new Vector4(ray->normal);
Vector4* I = new Vector4(ray->dir);
I->Scale(-1);
R_->Scale(2*N->DotProduct(I));
R_->Subtraction(I);
Vector4* end = new Vector4(ray->intersectPoint);
end->Addition(R_);
Ray* reflectedRay = new Ray(ray->intersectPoint, end);
delete(R_);
delete(I);
delete(end);
assert(dontCheckObject!=SPHERE);
RT_trace(reflectedRay, depth+1, dontCheckObject, dontCheckObjectID);
//For Debugging
// if(ray->intersectedObject==TRIANGLE/* && ray->intersectPoint->vector[1]<-2*screenX/4
// && ray->intersectPoint->vector[1]>-3*screenX/4*/){
// cout<<ray->intersectID;
// cout<<"---->";
// ray->normal->Display();
// cout<<"------>";
// I->Display();
// cout<<I->DotProduct(ray->normal)<<"\t";
// cout<<reflectedRay->dir->DotProduct(ray->normal);
// reflectedRay->dir->Display();
// cout<<": "<<reflectedRay->tIntersect<<"\t";
// reflectedRay->color->Display();
// cout<<endl;
// }
if(reflectedRay->tIntersect!=INFINITY){
reflectedRay->color->Scale(specularCoeff->vector[0], specularCoeff->vector[1], specularCoeff->vector[2]);
ray->color->Addition(reflectedRay->color);
}
delete(reflectedRay);
delete(N);
delete(V);
delete(specularCoeff);
delete(diffuseCoeff);
}
}
double FindNearestTIntersection(Ray* ray, int noCheckObject = NONE, int noCheckID = NONE){
assert((noCheckObject==NONE && noCheckID==NONE)
|| (noCheckObject==SPHERE && noCheckID>=0 && noCheckID<num_spheres)
|| (noCheckObject==TRIANGLE && noCheckID>=0 && noCheckID<num_triangles));
int dontCheckSphereID = NONE;
int dontCheckTriangleID = NONE;
if(noCheckObject==SPHERE){
dontCheckSphereID = noCheckID;
}
if(noCheckObject==TRIANGLE){
dontCheckTriangleID = noCheckID;
}
int index1 = NONE;
double nearestSphereIntersect = FindNearestTIntersectionWithSphere(ray,&index1, dontCheckSphereID);
int index2 = NONE;
double nearestTriangleIntersect = FindNearestTIntersectionWithTriangle(ray,&index2, dontCheckTriangleID);
// // For Debugging Purposes
// printf("[%f,%f]\t",nearestSphereIntersect,nearestTriangleIntersect);
int index = NONE;
double nearestTIntersect = INFINITY;
if (nearestSphereIntersect < nearestTriangleIntersect){
nearestTIntersect = nearestSphereIntersect;
index = index1;
}
else{
nearestTIntersect = nearestTriangleIntersect;
index = index2;
// // For Debugging Purposes
// intersectTriangle[index] = 1;
}
if (index != NONE) {
ray->intersectID = index;
ray->tIntersect = nearestTIntersect;
// Obtaining Intersection Point = P0 + t*dir
ray->intersectPoint->ReInitialize(ray->dir->vector);
ray->intersectPoint->Scale(nearestTIntersect);
ray->intersectPoint->Addition(ray->source);
ray->color->ReInitialize(ambient_light);
if (index == index1){
ray->intersectedObject = SPHERE;
// Obtaining normal at Intersection Point = intersectPoint - center
ray->normal->ReInitialize(spheres[index].position);
ray->normal->Scale(-1);
ray->normal->Addition(ray->intersectPoint);
ray->normal->ConvertToUnitVector();
// Assuming ambient coefficient = diffused coefficient, add ambient light
ray->color->Scale(spheres[index].color_diffuse[0], spheres[index].color_diffuse[1],
spheres[index].color_diffuse[2]);
}
else {
ray->intersectedObject = TRIANGLE;
// Obtaining normal at Intersection Point
double alpha = 0.0, beta = 0.0;
ObtainIntermediateTriangleIntersection(index, ray->intersectPoint, &alpha, &beta);
//printf("\n(%f,%f):%f\n",alpha,beta,ray->tIntersect);
InterpolateTriangleProperty(triangles[index].v[0].normal, triangles[index].v[1].normal,
triangles[index].v[2].normal, alpha, beta, ray->normal, true);
// Assuming ambient coefficient = diffused coefficient, add ambient light
Vector4* diffusedCoeff = new Vector4();
InterpolateTriangleProperty(triangles[index].v[0].color_diffuse, triangles[index].v[1].color_diffuse, triangles[index].v[2].color_diffuse,
alpha, beta, diffusedCoeff);
assert(diffusedCoeff->HasNonNegativeEntries());
ray->color->Scale(diffusedCoeff->vector[0], diffusedCoeff->vector[1], diffusedCoeff->vector[2]);
delete(diffusedCoeff);
}
}
return nearestTIntersect;
}