public DirectionalLight(Vect3D d)
{
_direction = d.Hat();
_intensity = 0.5f;
_color = new RGBColor(1, 1, 1);
_castsShadows = false;
}
public DirectionalLight(RGBColor c, float i, Vect3D d)
{
_color = new RGBColor(c);
_intensity = i;
_direction = d.Hat();
_castsShadows = false;
}
//Approximates the gradient of F(p) at a given point p
protected virtual Normal ApproximateNormal(Point3D p, Vect3D rd)
{
float f = EvaluateImplicitFunction(p);
float f_x = EvaluateImplicitFunction(new Point3D(p.X + EPSILON, p.Y, p.Z));
float f_y = EvaluateImplicitFunction(new Point3D(p.X, p.Y + EPSILON, p.Z));
float f_z = EvaluateImplicitFunction(new Point3D(p.X, p.Y, p.Z + EPSILON));
//Compute vector for normal
Vect3D raw_normal = (new Vect3D((float)(f_x - f), (float)(f_y - f), (float)(f_z - f))).Hat();
//Check if dot product is positive, if so, flip the vector so it's facing the ray origin
if(raw_normal * rd.Hat() > 0.0f) { raw_normal = -raw_normal; }
return (new Normal(raw_normal));
}