bool Plane::intersect(const Ray& ray, IntersectionData& intersectionData)
{
if ((ray.Start().Y() > this->Y() && ray.Direction().Y() > VerySmall) ||
(ray.Start().Y() < this->Y() && ray.Direction().Y() < VerySmall))
{
return false;
}
double yRayDirection = ray.Direction().Y();
double yDifference = ray.Start().Y() - this->Y();
double multiplier = yDifference / -yRayDirection;
if (multiplier > intersectionData.getDistance())
{
return false;
}
Vector intersectionPoint = ray.Start() + ray.Direction() * multiplier;
if (fabs(intersectionPoint.X()) > this->Limit() || fabs(intersectionPoint.Z()) > this->Limit())
{
return false;
}
intersectionData.setIntersectionPoint(intersectionPoint);
intersectionData.setDistance(multiplier);
intersectionData.setNormal(Vector(0.0, 1.0, 0.0));
intersectionData.setTextureU(intersectionData.IntersectionPoint().X());
intersectionData.setTextureV(intersectionData.IntersectionPoint().Z());
return true;
}
//-------------------------------------------------------------
SColor Scene :: IntersectShadow( Ray r, float maxt ) {
//-------------------------------------------------------------
SColor att = SColor(1);
Primitive3D * p;
while( (p = world.NextPrimitive( )) != NULL ) {
float t = p -> Intersect( r );
if ( t > EPSILON && t < maxt) {
Point x = r.Start() + r.Dir() * t;
att *= p -> kt( x );
}
}
return att;
}
//-------------------------------------------------------------
float Sphere :: Intersect( Ray& r ) {
//-------------------------------------------------------------
Vector dist = r.Start() - center;
float b = (dist * r.Dir()) * 2.0;
float a = (r.Dir() * r.Dir());
float c = (dist * dist) - radius * radius;
float discr = b * b - 4.0 * a * c;
if ( discr < 0 ) return -1;
float sqrt_discr = sqrt( discr );
float t1 = (-b + sqrt_discr)/2.0/a;
float t2 = (-b - sqrt_discr)/2.0/a;
if (t1 < EPSILON) t1 = -EPSILON;
if (t2 < EPSILON) t2 = -EPSILON;
if (t1 < 0 && t2 < 0) return -1;
float t;
if ( t1 < 0 && t2 >= 0 ) t = t2;
else if ( t2 < 0 && t1 >= 0 ) t = t1;
else if (t1 < t2) t = t1;
else t = t2;
return t;
}
