IntersectionInfo Sphere::rayIntersect(Ray _ray) {
Point3f e = _ray.e();
Point3f c = center_;
Vector3f d = _ray.d();
float discriminant = dot(d,(e-c))*dot(d,(e-c))-
dot(d,d)*(dot((e-c),(e-c))-radius_*radius_);
if (discriminant < 0.0) {
return IntersectionInfo(0.0,
Point3f(),
Vector3f(),
IntersectionInfo::miss());
} else {
float t1 = (dot(d*-1.0,(e-c))+sqrt(discriminant))/dot(d,d);
float t2 = (dot(d*-1.0,(e-c))-sqrt(discriminant))/dot(d,d);
float t;
if (t1 < t2) {
t = t1;
} else {
t = t2;
}
if (t < _ray.tMin() || t > _ray.tMax()) {
return IntersectionInfo(0.0,
Point3f(),
Vector3f(),
IntersectionInfo::miss());
}
Point3f p = e + d*t;
Vector3f n = 2.0*(p-c);
n.normalize();
return IntersectionInfo(t, p, n, IntersectionInfo::hit());
}
}
// _____________________________________________________________________________
void UniformGrid::intersectCellShapes(const glm::ivec3& index,
const Ray& ray,
std::vector<IntersectionInfo>* intersections) const {
auto it = m_Shapes.find(index);
if (it != m_Shapes.end()) {
const size_t numShapes = it->second.size();
for (size_t i = 0; i < numShapes; ++i) {
const std::pair<Shape*, uint64_t>& current = it->second.at(i);
Mesh* mesh;
if ((mesh = dynamic_cast<Mesh*>(current.first))) {
Ray transformedRay = mesh->getInverseTransformMatrix() * ray;
std::vector<size_t> hits;
std::vector<float> b1;
std::vector<float> b2;
std::vector<REAL> t = intersectTriangles(transformedRay,
mesh->getVertices(),
current.second, current.second + 3, &hits, &b1, &b2);
if (t.size() == 0) {
continue;
}
float tVal = t[0];
glm::vec4 position = ray.origin()
+ static_cast<float>(tVal) * ray.direction();
const std::vector<vec3>& normals = mesh->getNormals();
float beta = b1[0];
float gamma = b2[0];
float alpha = 1 - beta - gamma;
// printf("alpha/beta/gamma(%.2f/%.2f/%.2f)\n", alpha, beta, gamma);
intersections->push_back(IntersectionInfo(tVal,
position,
glm::normalize(mesh->getTransformMatrix() * glm::vec4(
((alpha * normals[current.second])
+ (beta * normals[current.second + 1])
+ (gamma * normals[current.second + 2])), 0.0f)),
mesh->getMaterialPtr(),
glm::vec2(0.0f)));
} else {
intersections->push_back(current.first->getIntersectionInfo(ray));
}
}
}
}
