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 calculateColour(r geometry.Ray,
depth float64,
scene geometry.Object,
object geometry.Object,
mat geometry.Material,
recursionLimit uint) (colour geometry.Vector) {
colour = mat.BaseColour.Mul(mat.CBase)
if mat.CReflectance != 0 && recursionLimit != 0 {
//calculate normal
normal := object.Normal(r, depth)
dir_proj := normal.Mul(normal.Dot(r.GetDirectionVector()))
reflectedDirection := dir_proj.Mul(2).Sub(r.GetDirectionVector())
incidence := r.Point(depth)
reflectedRay := geometry.MakeRay(incidence.Add(reflectedDirection.Mul(0.01)), reflectedDirection) //add a small amount so that it doesn't intersect the mirror
_, reflectedColour := castRay(reflectedRay, scene, recursionLimit-1)
colour = colour.Add(reflectedColour.Mul(mat.CReflectance))
}
return
}