private static Intersection getIntersection(Ray ray, SphereObject obj, Model model) {
RealMatrix transform = obj.getTransform();
final RealMatrix transformInverse = obj.getTransformInverse();
ray = ray.transform(transformInverse);
Vector3D c = VectorUtils.toVector3D(obj.getCenter());
Vector3D p0 = VectorUtils.toVector3D(ray.getP0());
Vector3D p1 = VectorUtils.toVector3D(ray.getP1());
float a = (float) p1.dotProduct(p1);
Vector3D p0c = p0.subtract(c);
float b = (float) p1.dotProduct(p0c) * 2.0f;
float cc = (float) (p0c.dotProduct(p0c)) - obj.getSize() * obj.getSize();
Double t = quadraticEquationRoot1(a, b, cc);
if (t == null || t < EPSILON) {
return new Intersection(false);
}
Intersection result = new Intersection(true);
result.setObject(obj);
final Vector3D p = p0.add(p1.scalarMultiply(t));
RealVector pv = VectorUtils.toRealVector(p);
pv.setEntry(3, 1.0);
RealVector pt = transform.preMultiply(pv);
result.setP(VectorUtils.toVector3D(pt));
RealVector nv = pv.subtract(obj.getCenter());
final RealVector nvt = transformInverse.transpose().preMultiply(nv);
result.setN(VectorUtils.toVector3D(nvt).normalize());
result.setDistance(t);
return result;
}
public static Intersection intersect(Ray ray, Model model) {
Intersection result = new Intersection(false);
int matchCount = 0;
for (DrawedObject obj : model.getObjects()) {
if (obj instanceof TriangleObject) {
Intersection intersection = getIntersection(ray, (TriangleObject) obj, model);
final boolean match = intersection.isMatch();
if (match) {
++matchCount;
}
if (match && intersection.getDistance() < result.getDistance()) {
result = intersection;
}
} else if (obj instanceof SphereObject) {
Intersection intersection = getIntersection(ray, (SphereObject) obj, model);
final boolean match = intersection.isMatch();
if (match) {
++matchCount;
}
if (match && intersection.getDistance() < result.getDistance()) {
result = intersection;
}
}
}
result.setIntersectionCount(matchCount);
return result;
}
private static int findColor(Intersection hit, Camera cam, Model model) {
if (hit.isMatch()) {
RealVector light = LightCalculations.computeLight(cam.getFrom3(), model, hit, 0);
return toColour(light);
}
return 0;
}
private static Intersection getIntersection(
TriangleObject obj, DecompositionSolver solver, Vector3D p, Vector3D pc, double[] params) {
RealVector constants = new ArrayRealVector(params, false);
RealVector solution = solver.solve(constants);
double alpfa = solution.getEntry(0);
double beta = solution.getEntry(1);
boolean match = false;
if (alpfa >= 0 && beta >= 0 && alpfa + beta <= 1.0) {
match = true;
} else {
match = false;
}
final Intersection intersection = new Intersection(match);
intersection.setObject(obj);
intersection.setP(p);
return intersection;
}
private static Intersection getIntersection(Ray ray, TriangleObject obj, Model model) {
Vector3D p0 = VectorUtils.toVector3D(ray.getP0());
Vector3D p1 = VectorUtils.toVector3D(ray.getP1());
Vector3D a = obj.getA();
Vector3D b = obj.getB();
Vector3D c = obj.getC();
Vector3D n = obj.getN();
double den = p1.dotProduct(n);
if (den != 0.0) {
double t = (a.dotProduct(n) - p0.dotProduct(n)) / den;
if (t < EPSILON) {
return new Intersection(false);
}
Vector3D p = p0.add(p1.scalarMultiply(t));
Vector3D pc = p.subtract(c);
final Intersection intersection = getIntersection(obj, p, pc);
if (intersection != null) {
intersection.setDistance(t);
return intersection;
}
}
return new Intersection(false);
}
