public override IntersectionInfo intersect(Ray ray)
{
IntersectionInfo info = new IntersectionInfo();
info.shape = this;
Vector3D dst = Vector3D.subtract(ray.position, this.position);
double B = dst.dot(ray.direction);
double C = dst.dot(dst) - (this.radius * this.radius);
double D = (B * B) - C;
if (D > 0)
{ // intersection!
info.isHit = true;
info.distance = (-B) - Math.Sqrt(D);
info.position = Vector3D.add(ray.position, Vector3D.multiplyScalar(ray.direction, info.distance));
info.normal = Vector3D.subtract(info.position, this.position).normalize();
info.color = this.material.getColor(0, 0);
}
else
{
info.isHit = false;
}
return(info);
}
public Color getPixelColor(Ray ray, Scene scene)
{
IntersectionInfo info = this.testIntersection(ray, scene, null);
if (info.isHit)
{
Color color = this.rayTrace(info, ray, scene, 0);
return(color);
}
return(scene.background.color);
}
public override IntersectionInfo intersect(Ray ray)
{
IntersectionInfo info = new IntersectionInfo();
double Vd = this.position.dot(ray.direction);
if (Vd == 0)
{
return(info); // no intersection
}
double t = -(this.position.dot(ray.position) + this.d) / Vd;
if (t <= 0)
{
return(info);
}
info.shape = this;
info.isHit = true;
info.position = Vector3D.add(ray.position, Vector3D.multiplyScalar(ray.direction, t));
info.normal = this.position;
info.distance = t;
if (this.material.hasTexture)
{
Vector3D vU = new Vector3D(this.position.y, this.position.z, -this.position.x);
Vector3D vV = vU.cross(this.position);
double u = info.position.dot(vU);
double v = info.position.dot(vV);
info.color = this.material.getColor(u, v);
}
else
{
info.color = this.material.getColor(0, 0);
}
return(info);
}
public IntersectionInfo testIntersection(Ray ray, Scene scene, BaseShape exclude)
{
int hits = 0;
IntersectionInfo best = new IntersectionInfo();
best.distance = 2000;
for (int i = 0; i < scene.shapes.Count; i++)
{
BaseShape shape = scene.shapes[i];
if (shape != exclude)
{
IntersectionInfo info = shape.intersect(ray);
if (info.isHit && info.distance >= 0 && info.distance < best.distance)
{
best = info;
hits++;
}
}
}
best.hitCount = hits;
return(best);
}
public Color rayTrace(IntersectionInfo info, Ray ray, Scene scene, int depth)
{
// Calc ambient
Color color = Color.multiplyScalar(info.color, scene.background.ambience);
Color oldColor = color;
double shininess = Math.Pow(10, info.shape.material.gloss + 1);
for (int i = 0; i < scene.lights.Count; i++)
{
Light light = scene.lights[i];
// Calc diffuse lighting
Vector3D v = Vector3D.subtract(light.position, info.position).normalize();
if (this.options.renderDiffuse)
{
double L = v.dot(info.normal);
if (L > 0.0)
{
color = Color.add(color, Color.multiply(info.color, Color.multiplyScalar(light.color, L)));
}
}
// The greater the depth the more accurate the colours, but
// this is exponentially (!) expensive
if (depth <= this.options.rayDepth)
{
// calculate reflection ray
if (this.options.renderReflections && info.shape.material.reflection > 0)
{
Ray reflectionRay = this.getReflectionRay(info.position, info.normal, ray.direction);
IntersectionInfo refl = this.testIntersection(reflectionRay, scene, info.shape);
if (refl.isHit && refl.distance > 0)
{
refl.color = this.rayTrace(refl, reflectionRay, scene, depth + 1);
}
else
{
refl.color = scene.background.color;
}
color = Color.blend(color, refl.color, info.shape.material.reflection);
}
// Refraction
/* TODO */
}
/* Render shadows and highlights */
IntersectionInfo shadowInfo = new IntersectionInfo();
if (this.options.renderShadows)
{
Ray shadowRay = new Ray(info.position, v);
shadowInfo = this.testIntersection(shadowRay, scene, info.shape);
if (shadowInfo.isHit && shadowInfo.shape != info.shape /*&& shadowInfo.shape.type != 'PLANE'*/)
{
Color vA = Color.multiplyScalar(color, 0.5);
double dB = (0.5 * Math.Pow(shadowInfo.shape.material.transparency, 0.5));
color = Color.addScalar(vA, dB);
}
}
// Phong specular highlights
if (this.options.renderHighlights && !shadowInfo.isHit && info.shape.material.gloss > 0)
{
Vector3D Lv = Vector3D.subtract(info.shape.position, light.position).normalize();
Vector3D E = Vector3D.subtract(scene.camera.position, info.shape.position).normalize();
Vector3D H = Vector3D.subtract(E, Lv).normalize();
double glossWeight = Math.Pow(Math.Max(info.normal.dot(H), 0), shininess);
color = Color.add(Color.multiplyScalar(light.color, glossWeight), color);
}
}
color.limit();
return(color);
}
