cv::Vec3b Camera::CastRay(Scene scene, Ray r)
{
std::vector<SpherePoint> Intersections =
FindIntersectionPoints(scene.GetSphereList(), r);
cv::Vec3b ReturnColor(255, 255, 255);
// If the ray intersected with any of them, find the closest point
if (Intersections.size() != 0)
{
Sphere ClosestSphere(Point(0,0,0),0,cv::Vec3b(0,0,0),Finish(0,0,0,0));
Point ClosestPoint(0, 0, 0);
double ShortestDistance = std::numeric_limits<double>::max();
for (auto& SpherePoint : Intersections)
{
Sphere& S = SpherePoint.s;
Point& P = SpherePoint.p;
double TempDist = r.Location.FromThisToThat(P).Length();
if (TempDist < ShortestDistance)
{
ShortestDistance = TempDist;
ClosestSphere = S;
ClosestPoint = P;
}
}
// Compute ambient component
cv::Vec3d& SceneAmb = scene.GetAmbientLightColor();
cv::Vec3b SphereAmbientColor = ClosestSphere.Color * ClosestSphere.Fin.Ambient;
SphereAmbientColor[0] *= SceneAmb[0];
SphereAmbientColor[1] *= SceneAmb[1];
SphereAmbientColor[2] *= SceneAmb[2];
// Compute diffuse component
// Translate the intersection point to avoid precision errors
cv::Vec3b DiffuseColor(0, 0, 0);
cv::Vec3b SpecularColor(0, 0, 0);
Vector SphereNormal = SphereNormalAtPoint(ClosestSphere, ClosestPoint);
ClosestPoint = ClosestPoint.Translate(SphereNormal * 0.01);
Vector PointToLight = ClosestPoint.FromThisToThat(scene.GetLightPosition()).Normalize();
// Check to see if intersection point is on the same side as the light
// And to make sure there is not another sphere in the way
double DotProduct = PointToLight.Dot(SphereNormal);
if (DotProduct > 0)
{
Intersections = FindIntersectionPoints(scene.GetSphereList(), Ray(ClosestPoint, PointToLight));
// Need to account for when spheres are past the light
if (Intersections.size() == 0)
{
cv::Vec3d& LightColor = scene.GetLightColor();
DiffuseColor = ClosestSphere.Color * ClosestSphere.Fin.Diffuse;
DiffuseColor[0] *= DotProduct * LightColor[0];
DiffuseColor[1] *= DotProduct * LightColor[1];
DiffuseColor[2] *= DotProduct * LightColor[2];
// Compute the specular light contribution
Vector ReflectionVector = PointToLight - (SphereNormal * (2 * DotProduct));
Vector ViewDirection = r.Location.FromThisToThat(ClosestPoint).Normalize();
double SpecIntensity = ReflectionVector.Dot(ViewDirection);
if (SpecIntensity > 0)
{
double Multiplier =
ClosestSphere.Fin.Specular *
std::pow(SpecIntensity, 1 / ClosestSphere.Fin.Roughness);
SpecularColor[0] = Multiplier * LightColor[0] * 255;
SpecularColor[1] = Multiplier * LightColor[1] * 255;
SpecularColor[2] = Multiplier * LightColor[2] * 255;
}
}
}
ReturnColor = SphereAmbientColor + DiffuseColor + SpecularColor;
}
return ReturnColor;
}
