markphelps

package primitives

type Lambertian struct {
	C Vector
}

func (l Lambertian) Bounce(input Ray, hit Hit) (bool, Ray) {
	direction := hit.Normal.Add(VectorInUnitSphere())
	return true, Ray{hit.Point, direction}
}

markphelps

var UnitVector = Vector{1, 1, 1}

// rejection method for finding random point on unit sphere
func VectorInUnitSphere() Vector {
	for {
		r := Vector{rand.Float64(), rand.Float64(), rand.Float64()}
		p := r.MultiplyScalar(2.0).Subtract(UnitVector)
		if p.SquaredLength() >= 1.0 {
			return p
		}

markphelps

package primitives

type Material interface {
	Bounce(input Ray, hit Hit) (bool, Ray)
	Color() Vector
}

markphelps

sphere = p.Sphere{p.Vector{0, 0, -1}, 0.5}
floor  = p.Sphere{p.Vector{0, -100.5, -1}, 100}

world = p.World{[]p.Hitable{&sphere, &floor}}

markphelps

type World struct {
	Elements []Hitable
}

func (w *World) Hit(r *Ray, tMin float64, tMax float64) (bool, HitRecord) {
	hitAnything := false
	closest := tMax
	record := HitRecord{}

	for _, element := range w.Elements {

markphelps

func (s *Sphere) Hit(r *Ray, tMin float64, tMax float64) (bool, HitRecord) {
 ...
}

markphelps

type Hitable interface {
	Hit(r *Ray, tMin float64, tMax float64) (bool, HitRecord)
}

markphelps

import (
	"fmt"

	p "github.com/markphelps/go-trace/primitives"
)

markphelps

...
for j := ny - 1; j >= 0; j-- {
  for i := 0; i < nx; i++ {
    rgb := p.Vector{}

    // sample rays for anti-aliasing
    for s := 0; s < 100; s++ {
      u := (float64(i) + rand.Float64()) / float64(nx)
      v := (float64(j) + rand.Float64()) / float64(ny)

markphelps

type HitRecord struct {
    T         float64
    P, Normal Vector
}