private ColorAccumulator CalculateLighting(HitInfo info, int count)
{
ColorAccumulator ca = new ColorAccumulator();
foreach (Light lt in Scene.Lights)
{
GetColor(info, lt, ca, count);
}
return ca;
}
public static ColorAccumulator operator +(ColorAccumulator left, ColorAccumulator right)
{
ColorAccumulator sum = new ColorAccumulator();
sum.R = left.R + right.R;
sum.G = left.G + right.G;
sum.B = left.B + right.B;
return(sum);
}
private ColorAccumulator CastRay(Ray ray, int count)
{
if (count > RayDepth)
{
return(null);
}
ColorAccumulator colorAccumulator = null;
HitInfo info = FindHitObject(ray);
if (info.hitObject != null)
{
colorAccumulator = CalculateLighting(info, count);
//colorAccumulator.Clamp();
}
else
{
colorAccumulator = new ColorAccumulator(BackColor.R, BackColor.G, BackColor.B);
}
return(colorAccumulator);
}
private ColorAccumulator CalculateLighting(HitInfo info, int count)
{
ColorAccumulator colorAccumulator = new ColorAccumulator();
foreach (Light light in Scene.Lights)
{
GetColor(info, light, colorAccumulator, count);
//Bidirectional ray tracing
var randomDirection = StaticRandom.RandomVectorInUnitSphere();
var randomRay = new Ray(light.Location + randomDirection, randomDirection);
var hitInfo = FindHitObject(randomRay);
var secondaryLight = new Light();
secondaryLight.Location = hitInfo.hitPoint - randomRay.Direction;
int squaredDistance = (int)(secondaryLight.Location - randomRay.Source).LengthSquared + 1;
secondaryLight.Color = light.Color;
secondaryLight.Intensity = light.Intensity / squaredDistance;
GetColor(info, secondaryLight, colorAccumulator, count);
}
return(colorAccumulator);
}
public static ColorAccumulator operator +(ColorAccumulator left, ColorAccumulator right)
{
ColorAccumulator sum = new ColorAccumulator();
sum.accumR = left.accumR + right.accumR;
sum.accumG = left.accumG + right.accumG;
sum.accumB = left.accumB + right.accumB;
return sum;
}
private void GetColor(HitInfo info, Light lt, ColorAccumulator ca, int count)
{
Vector3D lightNormal = info.hitPoint - lt.Location;
lightNormal.Normalize();
if (InShadow(info, lt, lightNormal))
{
return;
}
double lambert = Vector3D.DotProduct(lightNormal, info.normal);
if (lambert <= 0)
{
int r, g, b;
r = b = g = 0;
int r2 = 0;
int g2 = 0;
int b2 = 0;
info.hitObj.GetColor(info.hitPoint, ref r, ref g, ref b);
if (info.hitObj.Material != null && info.hitObj.Material is SolidColor)
{
double phongTerm = Math.Pow(lambert, 20) * (info.hitObj.Material as SolidColor).Phong * 2;
r2 = (int)(lt.Color.R * phongTerm);
g2 = (int)(lt.Color.G * phongTerm);
b2 = (int)(lt.Color.B * phongTerm);
double reflet = 2.0f * (Vector3D.DotProduct(info.normal, info.ray.Direction));
Vector3D dir = info.ray.Direction - info.normal * reflet;
Ray reflect = new Ray(info.hitPoint + dir, dir);
ColorAccumulator rca = CastRay(reflect, ++count);
if (rca != null)
{
ca.accumR = ca.accumR + rca.accumR;
ca.accumG = ca.accumG + rca.accumG;
ca.accumB = ca.accumB + rca.accumB;
}
}
ca.accumR += (int)((lt.Color.R * r * -lambert) / 255) + r2;
ca.accumG += (int)((lt.Color.G * g * -lambert) / 255) + g2;
ca.accumB += (int)((lt.Color.B * b * -lambert) / 255) + b2;
}
}
private ColorAccumulator CastRay(Ray ray, int count)
{
if (count > RayDepth)
{
return null;
}
ColorAccumulator ca = null;
HitInfo info = FindHitObject(ray);
if (info.hitObj != null)
{
ca = CalculateLighting(info, count);
ca.Clamp();
}
else
{
ca = new ColorAccumulator(BackColor.R, BackColor.G, BackColor.B);
}
return ca;
}
private void GetColor(HitInfo info, Light light, ColorAccumulator colorAccu, int count)
{
Vector3D lightLocation = light.Location;
Vector3D lightNormal = info.hitPoint - lightLocation;
lightNormal.Normalize();
double lambert = Vector3D.DotProduct(lightNormal, info.normal);
if (lambert <= 0)
{
int r, g, b;
r = g = b = 0;
int r2 = 0;
int g2 = 0;
int b2 = 0;
info.hitObject.GetColor(info.hitPoint, ref r, ref g, ref b);
if (info.hitObject.Material != null)
{
var objectMaterial = info.hitObject.Material;
//Phong
if (objectMaterial is SolidColor)
{
if (InShadow(info, lightLocation, lightNormal))
{
return;
}
double phongTerm = Math.Pow(lambert, 20) * (objectMaterial as SolidColor).Phong * 2 * light.Intensity;
r2 = (int)(light.Color.R * phongTerm);
g2 = (int)(light.Color.G * phongTerm);
b2 = (int)(light.Color.B * phongTerm);
var intensityFactor = light.Intensity * -lambert / 255;
colorAccu.R += (int)(light.Color.R * r * intensityFactor) + r2;
colorAccu.G += (int)(light.Color.G * g * intensityFactor) + g2;
colorAccu.B += (int)(light.Color.B * b * intensityFactor) + b2;
}
//Reflection
else if (objectMaterial is Metal)
{
var metal = objectMaterial as Metal;
//double phongTerm = Math.Pow(lambert, 20) * 0.6 * 2 * light.Intensity;
//r2 = (int)(light.Color.R * phongTerm);
//g2 = (int)(light.Color.G * phongTerm);
//b2 = (int)(light.Color.B * phongTerm);
double reflet = 2.0f * (Vector3D.DotProduct(info.normal, info.ray.Direction));
Vector3D direction = info.ray.Direction - info.normal * reflet;
direction.Normalize();
direction += metal.Fuzz * StaticRandom.RandomVectorInUnitSphere(); //Random in cone
//direction.Normalize();
Ray reflect = new Ray(info.hitPoint + direction / 100000, direction);
ColorAccumulator reflectedColorAccu = CastRay(reflect, ++count);
if (reflectedColorAccu != null)
{
var attenuation = metal.Reflection * light.Intensity;
colorAccu.R += (int)(reflectedColorAccu.R * attenuation) + r2;
colorAccu.G += (int)(reflectedColorAccu.G * attenuation) + g2;
colorAccu.B += (int)(reflectedColorAccu.B * attenuation) + b2;
}
}
}
}
}
