// spawn a shadow ray from the intersection point to the light source.
private static bool spawnShadow(Light bulb, Hit finalHit, Shape hitShape, Shape fromShape)
{
Ray shadowRay = new Ray();
shadowRay.start = finalHit.intersect;
shadowRay.direction = Point3.vectorize(shadowRay.start, bulb.Location);
double shadowDist = Point3.distance(shadowRay.start, bulb.Location);
foreach (Shape s in layout.Shapes)
{
// If this is the object we're checking from, ignore. Duh.
if (s.Equals(hitShape) || s.Equals(fromShape) || s.Material.Kt > 0)
{
continue;
}
Hit shadowHit = s.intersect(shadowRay);
if (shadowHit.intersect.z == Constants.FAR_AWAY)
{
continue;
}
// We need to check if hitShape object is in FRONT OF the current one. if it is, we need to ignore this current shape.
Vector3 frontTest = Point3.vectorize(shadowHit.intersect, finalHit.intersect);
if (frontTest.X > 0 && frontTest.Y > 0 && frontTest.Z > 0)
{
continue;
}
// something has to come between the light and the current shape.
double shapeDist = Point3.distance(shadowRay.start, shadowHit.intersect);
if (shapeDist < shadowDist)
{
return(true);
}
}
return(false);
}
private static Color3 fireRay(Ray incomingRay, int depth, Shape fromShape)
{
double closest = Constants.FAR_AWAY;
Color3 retColor = Constants.BGCOLOR;
int whichObject = 0, hitObject = 0;
Hit finalHit = new Hit();
foreach (Shape s in layout.Shapes)
{
Hit rayHit = s.intersect(incomingRay);
whichObject++;
if (rayHit.intersect.z == Constants.FAR_AWAY)
{
continue;
}
double dist = Point3.distance(layout.Cam.Eye, rayHit.intersect);
if (dist < closest && !s.Equals(fromShape))
{
closest = dist;
hitObject = whichObject;
finalHit = rayHit;
}
}
if (hitObject <= 0)
{
return(Constants.BGCOLOR);
}
Shape hitShape = layout.Shapes[hitObject - 1];
retColor = Color3.ambient(hitShape);
// phongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphongphong
Color3 diffuseColor = Color3.Black, specularColor = Color3.Black;
foreach (Light bulb in layout.Lights)
{
if (spawnShadow(bulb, finalHit, hitShape, fromShape))
{
retColor = hitShape.colorShadow(retColor, finalHit, layout.Lights.Count * 3);
}
else
{
if (hitShape is Plane)
{
retColor = hitShape.colorNormal(retColor, incomingRay, finalHit, hitShape, bulb);
}
else
{
diffuseColor += Color3.diffuse(finalHit, hitShape, bulb);
specularColor += Color3.specular(incomingRay, finalHit, hitShape, bulb);
}
}
}
if (hitShape is Sphere)
{
retColor += diffuseColor * hitShape.Material.Kd;
retColor += specularColor * hitShape.Material.Ks;
}
if (depth < Constants.MAX_DEPTH)
{
Color3 reflectColor = Color3.Black;
if (hitShape.Material.Kr > 0)
{
Ray reflectRay = new Ray();
reflectRay.start = finalHit.intersect;
Vector3 normalVec = hitShape.calcNormal(finalHit);
double c = -Vector3.DotProduct(normalVec, incomingRay.direction);
reflectRay.direction = -(incomingRay.direction + (2 * normalVec * c));
reflectRay.direction.Normalize();
reflectColor = fireRay(reflectRay, depth + 1, hitShape);
retColor += reflectColor * hitShape.Material.Kr;
}
if (hitShape.Material.Kt > 0)
{
Ray transRay = new Ray();
double indexRefract;
Vector3 normalVec = Vector3.FaceForward(hitShape.calcNormal(finalHit), -incomingRay.direction);
if (Vector3.DotProduct(-incomingRay.direction, hitShape.calcNormal(finalHit)) < 0)
{
indexRefract = Constants.REFRACTION_INDEX_SPHERE / Constants.REFRACTION_INDEX_AIR;
}
else
{
indexRefract = Constants.REFRACTION_INDEX_AIR / Constants.REFRACTION_INDEX_SPHERE;
}
double discrim = 1 + (Math.Pow(indexRefract, 2) * (Math.Pow(Vector3.DotProduct(-incomingRay.direction, normalVec), 2) - 1));
// Total internal reflection!
if (discrim < 0)
{
retColor += reflectColor * hitShape.Material.Kt;
}
else
{
discrim = indexRefract * Vector3.DotProduct(-incomingRay.direction, normalVec) - Math.Sqrt(discrim);
transRay.direction = (indexRefract * incomingRay.direction) + (discrim * normalVec);
transRay.start = finalHit.intersect;
Color3 transColor = fireRay(transRay, depth + 1, hitShape);
retColor += transColor * hitShape.Material.Kt;
}
}
}
return(retColor);
}