@Override
public Illumination illuminate(Vec3D point) {
Vec3D lightDirection = point.subtract(position);
double r2 = lightDirection.dotProduct(lightDirection);
double distance = Math.sqrt(r2);
lightDirection = lightDirection.multiply(1 / distance);
Vec3D lightIntensity = color.multiply(intensity / (4 * Math.PI * r2));
return new Illumination(lightDirection, lightIntensity, distance);
}
@Override
public Double intersect(Ray ray) {
// Moller-Trumbore algorithm
Vec3D v0v1 = v1.subtract(v0);
Vec3D v0v2 = v2.subtract(v0);
Vec3D pvec = ray.direction.crossProduct(v0v2);
normal = v0v1.crossProduct(v0v2).normalize();
double det = v0v1.dotProduct(pvec);
if (Options.culling)
if (det < Options.kEpsilon) return null;
else if (Math.abs(det) < Options.kEpsilon) return null;
double invDet = 1 / det;
Vec3D tvec = ray.origin.subtract(v0);
u = tvec.dotProduct(pvec) * invDet;
if (u < 0 || u > 1) return null;
Vec3D qvec = tvec.crossProduct(v0v1);
v = ray.direction.dotProduct(qvec) * invDet;
if (v < 0 || u + v > 1) return null;
return v0v2.dotProduct(qvec) * invDet;
}