func main() {
plane := geometry.YAxisAlignedPlane{0}
cube1 := geometry.MakeCuboid(geometry.MakeVector(-2, 0, 0), geometry.MakeVector(0.5, 0.5, 0.5))
sphere := geometry.MakeSphere(geometry.MakeVector(2, 0, 0), 2.0)
sphere2 := geometry.MakeSphere(geometry.MakeVector(-2, 2, 0), 0.5)
//cube2 := geometry.MakeCuboid(geometry.MakeVector(1,0,0),geometry.MakeVector(0.5, 0.5, 0.5))
n := geometry.MakeTreeNode(sphere2, cube1)
scene := geometry.MakeTreeNode(plane, n)
scene = geometry.MakeTreeNode(sphere, scene)
//cube := geometry.MakeCuboid(geometry.MakeVector(-2,0,0),geometry.MakeVector(0.5, 0.5, 0.5))
//scene := geometry.MakeTreeNode(sphere, cube)
img := render.RenderImage(1366, 768, scene)
f, err := os.Create("out.png")
if err != nil {
fmt.Println(err)
os.Exit(-1)
}
png.Encode(f, img)
}
func MakeViewRay(u, v, k float64) geometry.Ray {
//var d1 float64 = math.Sqrt(1/(2+4*sinθ2))
// = math.Sqrt(5/14)
const d1 float64 = 0.5976143046671968
//var d2 float64 = -2*sinθ*d1
const d2 float64 = -2 * sinθ * d1
// = -math.Sqrt(2/7)
d := geometry.MakeVector(d1, d2, d1)
bu := geometry.MakeVector(1.0/math.Sqrt(2), 0, -1.0/math.Sqrt(2))
var bv1 float64 = math.Sqrt(1.0 / 7.0) //math.Sqrt(1/(2 + 1/sinθ2))
var bv2 float64 = math.Sqrt(5.0 / 7.0) //bv1/sinθ
bv := geometry.MakeVector(bv1, bv2, bv1)
//fmt.Println(bu.Dot(d), bv.Dot(d), bu.Dot(bv))
o := (bu.Mul(u)).Add(bv.Mul(v)).Add(d.Mul(k))
return geometry.MakeRay(o, d)
}
func castRay(r geometry.Ray, scene geometry.Object, recursionLimit uint) (bool, geometry.Vector) {
if scene.Collides(r) {
depth, object, objectColour := scene.Collision(r)
// if depth < 0 {
// return false, geometry.MakeVector(0,0,0)
// }
// if recursionLimit == 4 {
// fmt.Println("Reflected")
// }
return true, calculateColour(r, depth, scene, object, objectColour, recursionLimit)
}
return false, geometry.MakeVector(0, 0, 0)
}
func RenderImage(width, height uint32, scene geometry.Object) *image.RGBA {
distance := -10.0
const scale float64 = 7.0
const subsamples int = 8
img := image.NewRGBA(image.Rect(0, 0, int(width), int(height)))
b := img.Bounds()
for y := b.Min.Y; y <= b.Max.Y; y++ {
for x := b.Min.X; x <= b.Max.X; x++ {
x_range := b.Max.X - b.Min.X
y_range := b.Max.Y - b.Min.Y
fxr := float64(x_range)
fyr := float64(y_range)
colour := geometry.MakeVector(0, 0, 0)
for i := 0; i < subsamples; i++ {
xjitter := 0.5*rand.Float64() - 0.25
yjitter := 0.5*rand.Float64() - 0.25
if i == 0 { //Always cast a ray through the middle
xjitter = 0
yjitter = 0
}
u := (scale / fxr) * (fxr / fyr) * (float64(x-x_range/2) + xjitter)
v := -(scale / fyr) * (float64(y-y_range/2) + yjitter)
r := MakeViewRay(u, v, distance)
//r := MakeViewRay(math.Abs(distance)*u, math.Abs(distance)*v, distance)
collision, c := castRay(r, scene, 5)
if collision {
colour = colour.Add(c)
}
}
colour = colour.Apply(func(x float64) float64 {
return math.Abs(x) / float64(subsamples)
})
//if colour.y != 0{
//fmt.Println(colour.y)
//}
c := colour.ToArray()
img.Set(x, y, color.RGBA{uint8(c[0]), uint8(c[1]), uint8(c[2]), 255})
}
}
return img
}