func BloomFilter(img [][]geometry.Vec3, depth int) [][]geometry.Vec3 {
data := make([][]geometry.Vec3, len(img))
for i, _ := range data {
data[i] = make([]geometry.Vec3, len(img[0]))
}
const box_width = 2
factor := geometry.Float(1.0 / math.Pow(2*box_width+1, 2))
source := img
for iteration := 0; iteration < depth; iteration++ {
for y := box_width; y < len(img)-box_width; y++ {
for x := box_width; x < len(img[0])-box_width; x++ {
var colour geometry.Vec3
for dy := -box_width; dy <= box_width; dy++ {
for dx := -box_width; dx <= box_width; dx++ {
colour.AddInPlace(source[y+dy][x+dx])
}
}
data[y][x] = colour.Mult(factor)
}
}
fmt.Printf("\rPost Processing %3.0f%% \r", 100*float64(iteration)/float64(depth))
source, data = data, source
}
return source
}
func MonteCarloPixel(results chan Result, scene *geometry.Scene, diffuseMap /*, causticsMap*/ *kd.KDNode, start, rows int, rand *rand.Rand) {
samples := Config.NumRays
var px, py, dy, dx geometry.Float
var direction, contribution geometry.Vec3
for y := start; y < start+rows; y++ {
py = scene.Height - scene.Height*2*geometry.Float(y)/geometry.Float(scene.Rows)
for x := 0; x < scene.Cols; x++ {
px = -scene.Width + scene.Width*2*geometry.Float(x)/geometry.Float(scene.Cols)
var colourSamples geometry.Vec3
if x >= Config.Skip.Left && x < scene.Cols-Config.Skip.Right &&
y >= Config.Skip.Top && y < scene.Rows-Config.Skip.Bottom {
for sample := 0; sample < samples; sample++ {
dy, dx = geometry.Float(rand.Float32())*scene.PixH, geometry.Float(rand.Float32())*scene.PixW
direction = geometry.Vec3{
px + dx - scene.Camera.Origin.X,
py + dy - scene.Camera.Origin.Y,
-scene.Camera.Origin.Z,
}.Normalize()
contribution = Radiance(geometry.Ray{scene.Camera.Origin, direction}, scene, diffuseMap /*causticsMap,*/, 0, 1.0, rand)
colourSamples.AddInPlace(contribution)
}
}
results <- Result{x, y, colourSamples.Mult(1.0 / geometry.Float(samples))}
}
}
}
func DiffusePhoton(scene []*geometry.Shape, emitter *geometry.Shape, ray geometry.Ray, colour geometry.Vec3, result chan<- PhotonHit, alpha geometry.Float, depth int, rand *rand.Rand) {
if geometry.Float(rand.Float32()) > alpha {
return
}
if shape, distance := ClosestIntersection(scene, ray); shape != nil {
impact := ray.Origin.Add(ray.Direction.Mult(distance))
if depth == 0 && emitter == shape {
// Leave the emitter first
nextRay := geometry.Ray{impact, ray.Direction}
DiffusePhoton(scene, emitter, nextRay, colour, result, alpha, depth, rand)
} else {
normal := shape.NormalDir(impact).Normalize()
reverse := ray.Direction.Mult(-1)
outgoing := normal
if normal.Dot(reverse) < 0 {
outgoing = normal.Mult(-1)
}
strength := colour.Mult(alpha / (1 + distance))
result <- PhotonHit{impact, strength, ray.Direction, uint8(depth)}
if shape.Material == geometry.DIFFUSE {
// Random bounce for color bleeding
u := normal.Cross(reverse).Normalize().Mult(geometry.Float(rand.NormFloat64() * 0.5))
v := u.Cross(normal).Normalize().Mult(geometry.Float(rand.NormFloat64() * 0.5))
bounce := geometry.Vec3{
u.X + outgoing.X + v.X,
u.Y + outgoing.Y + v.Y,
u.Z + outgoing.Z + v.Z,
}
bounceRay := geometry.Ray{impact, bounce.Normalize()}
bleedColour := colour.MultVec(shape.Colour).Mult(alpha / (1 + distance))
DiffusePhoton(scene, shape, bounceRay, bleedColour, result, alpha*0.66, depth+1, rand)
}
// Store Shadow Photons
shadowRay := geometry.Ray{impact, ray.Direction}
DiffusePhoton(scene, shape, shadowRay, geometry.Vec3{0, 0, 0}, result, alpha*0.66, depth+1, rand)
}
}
}