private void AddCube(float cube_half_size, Point3d point, Color color, float specular = 0, float reflecive = 0, float transparent = 0)
{
var cube = new Polyhedron();
cube.MakeHexahedron(cube_half_size);
cube.Translate(point.X, point.Y, point.Z);
cube.color = color;
cube.specular = specular;
cube.reflective = reflecive;
cube.transparent = transparent;
cube.FindNormals();
polyhedrons.Add(cube);
}
private void AddWall(List <Point3d> points, List <float> normal, Color color, float specular = 0, float reflective = 0)
{
Face f = new Face(points);
var wall = new Polyhedron(new List <Face>()
{
f
});
wall.Faces[0].Normal = normal;
wall.color = color;
wall.specular = specular;
wall.reflective = reflective;
polyhedrons.Add(wall);
}
private PointF IntersectRaySphere(Point3d camera, Point3d D, Polyhedron sphere)
{
PointF res = new Point(inf, inf);
float r = sphere.radius;
Point3d OC = Sub(camera, sphere.Center);
float k1 = Dot(D, D);
float k2 = 2 * Dot(OC, D);
float k3 = Dot(OC, OC) - r * r;
float discriminant = k2 * k2 - 4 * k1 * k3;
if (discriminant < 0)
{
return(res);
}
double t1 = (-k2 + Math.Sqrt(discriminant)) / (2 * k1);
double t2 = (-k2 - Math.Sqrt(discriminant)) / (2 * k1);
res.X = (float)t1;
res.Y = (float)t2;
return(res);
}
private void ClosestIntersection(Point3d camera, Point3d D, float t_min, float t_max, ref Polyhedron closest, ref float closest_t, ref Point3d norm)
{
closest_t = inf;
closest = null;
norm = null;
foreach (var polyhedron in polyhedrons)
{
if (polyhedron.is_sphere)
{
PointF t = IntersectRaySphere(camera, D, polyhedron);
if (t.X < closest_t && t_min < t.X && t.X < t_max)
{
closest_t = t.X;
closest = polyhedron;
}
if (t.Y < closest_t && t_min < t.Y && t.Y < t_max)
{
closest_t = t.Y;
closest = polyhedron;
}
}
else
{
Point3d norm_res = null;
float t = IntersectRay(camera, D, polyhedron, ref norm_res);
if (t < closest_t && t_min < t && t < t_max)
{
closest_t = t;
closest = polyhedron;
norm = norm_res;
}
}
}
if (closest != null && closest.is_sphere)
{
var point = Sum(camera, Mul(closest_t, D));
norm = Sub(point, closest.Center);
}
}