bool Tri::intersect(Ray& _ray, float* thit, Intersection* in) {
Ray ray = _ray.transform(inverseTransform);
if (!intersectP(ray)) { return false; }
if (*thit < t) { return false; }
p = ray.getPos() + ray.getDir() * t;
w = p - a;
vCrossW = glm::cross(v, w);
uCrossW = glm::cross(u, w);
if (glm::dot(vCrossW, vCrossU) < 0) { return false; }
if (glm::dot(uCrossW, uCrossV) < 0) { return false; }
beta = glm::length(vCrossW)/denom;
gamma = glm::length(uCrossW)/denom;
alpha = 1 - beta - gamma;
if (!(beta <= 1 && gamma <= 1 && beta + gamma <= 1)) { return false; }
*thit = t;
in->localGeo.pos = mat4TimesVec3(getTransform(),
(ray.getPos() + t * ray.getDir()), 1.0);
in->localGeo.normal = getNormal();
//shift position slightly towards normal (epsilon shift)
in->localGeo.pos = in->localGeo.pos + in->localGeo.normal * epsilon;
in->primitive = this;
return true;
}
/**
* Intersect a Ray with a plane defined by the 4 coefficients Ax + By + Cz + D = 0.
* A,B,C are the plane normal
*/
bool planeIntersect(const Ray& r, const float *plane, PointF& intersection) {
Normal normal(plane[0], plane[1], plane[2]);
const PointF& rp = r.getPos();
float dotNormalRayDir = Math::dot3(normal, r.getDir());
// Is the ray perpendicular to the plane's normal?
if (fabs(dotNormalRayDir) < PLANE_INTERSECTION_THRESHOLD) {
return false;
}
// Determine which side of the plane the point is on
float distFromPlane = Math::dot3(normal, rp) + plane[3];
float t = distFromPlane/dotNormalRayDir;
// > 0 if ray and normal are in the same direction and
// the ray is on the normal side of the plane or
// If the ray and normal point in opposite directions and
// the ray is not on the normal side of the plane
if (t > 0) {
return false;
}
intersection = Math::vec3AXPlusB(r.getDir(), -t, r.getPos());
return true;
}
bool World::intersect(Ray & r, double & bestT, vec3 &outn, MaterialInfo &outm) {
bestT = numeric_limits<double>::infinity();
if (_DEBUG_INTERSECT1
&& abs(r.direction()[0] - 0.146734796) < 0.05
&& abs(r.direction()[1] + 0.146734796) < 0.05
&& abs(r.direction()[2] + 0.978231971) < 0.05)
int i = 0; //debug statement, stops at a ray aimed at the center of one of the spheres in threespheres.scd
if (_DEBUG_INTERSECT2
&& abs(r.direction()[0] + 0.114776942) < 0.02
&& abs(r.direction()[1] - 0.0619082097) < 0.02
&& abs(r.direction()[2] + 0.991460351) < 0.02)
int i = 0; // debug statement, stops at a ray aimed for the left eye of the bunny in ellipsoids.scd
if (_ASSIGNMENT <= 5 || _FINAL_PROJ) {
// iterate through spheres to see if any of them are intersected
for (vector<Sphere>::iterator sphere = _spheres.begin(); sphere != _spheres.end(); sphere++) {
double intersect = sphere->intersect(r);
if (intersect < bestT) {
//cout << "intersect found" << endl;
bestT = intersect;
//cout << intersect << " ";
vec4 pos = r.getPos(intersect);
//cout << pos[0] << "," << pos[1] << "," << pos[2] << " ";
outn = vec3(sphere->calculateNormal(pos), VW);
//cout << outn[0] << "," << outn[1] << "," << outn[2] << endl;
outm = sphere->getMaterial();
//AS4 stuff
//if (sphere == _spheres.begin()) {
// outm.k[MAT_KSM] *= ksmMod;
// outm.k[MAT_KSP] *= kspMod;
// if (outm.k[MAT_KSP] < 1.0) outm.k[MAT_KSP] = 1.0;
//}
}
}
for (vector<Cube>::iterator cube = _cubes.begin(); cube != _cubes.end(); cube++) {
double intersect = cube->intersect(r);
if (intersect < bestT) {
bestT = intersect;
vec4 pos = r.getPos(intersect);
outn = vec3(cube->calculateNormal(pos), VW);
outm = cube->getMaterial();
outm.color = cube->calculateColor(pos);
}
}
return bestT < numeric_limits<double>::infinity();
}
else
return _bb->intersect(r, bestT, outn, outm);
}
bool intersect_search(Ray ray, Triangle* trig, int nTriangles, PoI* poi)
{
float min_hit = 99999;
int count = 0;
float t_hit;
for (count = 0; count < nTriangles; count ++)
{
Triangle t = trig[count];
//t.scale(2, 1, 1); //scale by x-axis by 2
bool hit = t.hit(ray, &t_hit);
if (hit && t_hit < min_hit)
{
min_hit = t_hit;
poi->setCollision(ray.getDir() * min_hit + ray.getPos());
poi->setColor(t.kd);
Vector myNorm = t.getNormal();
//if normal faces the wrong way, then needs to do soemthing about it
//cos(angle) = dot_product / (a.len * b.len)
float cosine = myNorm.Vdot(ray.getDir()) / (myNorm.getMag() * ray.getDir().getMag());
if (cosine < 0)
{
myNorm = myNorm * -1;
}
poi->setNormal(t.getNormal());
}
}
if (min_hit != 99999)
{
return true;
}
return false;
}
bool Tri::intersectP(Ray& ray) {
t = (glm::dot(a, planeNormal) - glm::dot(ray.getPos(), planeNormal)) /
glm::dot(ray.getDir(), planeNormal);
if (t > 0) { return true; }
else { return false; }
}