Created
January 28, 2019 16:16
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tinykaboom with gfx
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| package main | |
| import ( | |
| "image" | |
| "image/color" | |
| "math" | |
| "github.com/peterhellberg/gfx" | |
| ) | |
| var ( | |
| sphereRadius = 1.5 | |
| noiseAmplitude = 0.2 | |
| ) | |
| func main() { | |
| frame := render(640, 480, math.Pi/3.0) | |
| gfx.SavePNG("/tmp/gfx-tinykaboom-step5.png", frame) | |
| } | |
| func render(width, height int, fov float64) *Frame { | |
| frame := NewFrame(width, height) | |
| fw, fh := float64(width), float64(height) | |
| for j := 0; j < height; j++ { | |
| for i := 0; i < width; i++ { | |
| fi, fj := float64(i), float64(j) | |
| dir := gfx.V3((fi+0.5)-fw/2, -(fj+0.5)+fh/2, -fh/(2*math.Tan(fov/2))) | |
| if hit, ok := sphereTrace(gfx.V3(0, 0, 3), dir.Norm()); ok { | |
| ld := gfx.V3(10, 10, 10).Sub(hit).Norm() | |
| li := math.Max(0.4, ld.Dot(distanceFieldNormal(hit))) | |
| frame.Buffer[i+j*width] = gfx.V3(1, 1, 1).Mul(li) | |
| } else { | |
| frame.Buffer[i+j*width] = gfx.V3(0.1, 0.1, 0.1) | |
| } | |
| } | |
| } | |
| return frame | |
| } | |
| func signedDistance(p gfx.Vec3) float64 { | |
| d := math.Sin(16*p.X) * math.Sin(16*p.Y) * math.Sin(16*p.Z) * noiseAmplitude | |
| return p.SqLen() - (sphereRadius + d) | |
| } | |
| func sphereTrace(orig, dir gfx.Vec3) (gfx.Vec3, bool) { | |
| pos := orig | |
| for i := 0; i < 128; i++ { | |
| d := signedDistance(pos) | |
| if d < 0 { | |
| return pos, true | |
| } | |
| pos = pos.Add(dir.Mul(math.Max(d*0.1, 0.01))) | |
| } | |
| return pos, false | |
| } | |
| func distanceFieldNormal(pos gfx.Vec3) gfx.Vec3 { | |
| const eps = 0.1 | |
| d := signedDistance(pos) | |
| nx := signedDistance(pos.Add(gfx.V3(eps, 0, 0))) - d | |
| ny := signedDistance(pos.Add(gfx.V3(0, eps, 0))) - d | |
| nz := signedDistance(pos.Add(gfx.V3(0, 0, eps))) - d | |
| return gfx.V3(nx, ny, nz).Norm() | |
| } | |
| type Frame struct { | |
| Buffer []gfx.Vec3 | |
| bounds image.Rectangle | |
| gfx.Float64Scaler | |
| } | |
| func NewFrame(w, h int) *Frame { | |
| return &Frame{ | |
| Buffer: make([]gfx.Vec3, w*h), | |
| bounds: gfx.IR(0, 0, w, h), | |
| Float64Scaler: gfx.NewLinearScaler().Domain(0, 1).Range(0, 255), | |
| } | |
| } | |
| func (f *Frame) At(x, y int) color.Color { | |
| v := f.Buffer[x+y*f.bounds.Max.X] | |
| return color.NRGBA{ | |
| uint8(f.ScaleFloat64(v.X)), | |
| uint8(f.ScaleFloat64(v.Y)), | |
| uint8(f.ScaleFloat64(v.Z)), | |
| 255, | |
| } | |
| } | |
| func (f *Frame) Bounds() image.Rectangle { | |
| return f.bounds | |
| } | |
| func (f *Frame) ColorModel() color.Model { | |
| return color.NRGBAModel | |
| } |
Step 3: let us draw a pattern on our sphere
package main
import (
"image"
"image/color"
"math"
"github.com/peterhellberg/gfx"
)
const (
sphereRadius = 1.5
noiseAmplitude = 0.2
)
func main() {
frame := render(640, 480, math.Pi/3.0)
gfx.SavePNG("/tmp/gfx-tinykaboom-step3.png", frame)
}
func render(width, height int, fov float64) *Frame {
frame := NewFrame(width, height)
fw, fh := float64(width), float64(height)
for j := 0; j < height; j++ {
for i := 0; i < width; i++ {
fi, fj := float64(i), float64(j)
dir := gfx.V3((fi+0.5)-fw/2, -(fj+0.5)+fh/2, -fh/(2*math.Tan(fov/2)))
if hit, ok := sphereTrace(gfx.V3(0, 0, 3), dir.Norm()); ok {
ld := gfx.V3(10, 10, 10).Sub(hit).Norm()
li := math.Max(0.4, ld.Dot(distanceFieldNormal(hit)))
d := (math.Sin(16*hit.X)*math.Sin(16*hit.Y)*math.Sin(16*hit.Z) + 1) / 2
frame.Buffer[i+j*width] = gfx.V3(1, 1, 1).Mul(d * li)
} else {
frame.Buffer[i+j*width] = gfx.V3(0.1, 0.1, 0.1)
}
}
}
return frame
}
func signedDistance(p gfx.Vec3) float64 {
return p.SqLen() - sphereRadius
}
func sphereTrace(orig, dir gfx.Vec3) (gfx.Vec3, bool) {
pos := orig
for i := 0; i < 128; i++ {
d := signedDistance(pos)
if d < 0 {
return pos, true
}
pos = pos.Add(dir.Mul(math.Max(d*0.1, 0.01)))
}
return pos, false
}
func distanceFieldNormal(pos gfx.Vec3) gfx.Vec3 {
const eps = 0.1
d := signedDistance(pos)
nx := signedDistance(pos.Add(gfx.V3(eps, 0, 0))) - d
ny := signedDistance(pos.Add(gfx.V3(0, eps, 0))) - d
nz := signedDistance(pos.Add(gfx.V3(0, 0, eps))) - d
return gfx.V3(nx, ny, nz).Norm()
}
type Frame struct {
Buffer []gfx.Vec3
bounds image.Rectangle
gfx.Float64Scaler
}
func NewFrame(w, h int) *Frame {
return &Frame{
Buffer: make([]gfx.Vec3, w*h),
bounds: gfx.IR(0, 0, w, h),
Float64Scaler: gfx.NewLinearScaler().Domain(0, 1).Range(0, 255),
}
}
func (f *Frame) At(x, y int) color.Color {
v := f.Buffer[x+y*f.bounds.Max.X]
return color.NRGBA{
uint8(f.ScaleFloat64(v.X)),
uint8(f.ScaleFloat64(v.Y)),
uint8(f.ScaleFloat64(v.Z)),
255,
}
}
func (f *Frame) Bounds() image.Rectangle {
return f.bounds
}
func (f *Frame) ColorModel() color.Model {
return color.NRGBAModel
}
Step 4: displacement mapping
package main
import (
"image"
"image/color"
"math"
"github.com/peterhellberg/gfx"
)
const (
sphereRadius = 1.5
noiseAmplitude = 0.2
)
func main() {
frame := render(640, 480, math.Pi/3.0)
gfx.SavePNG("/tmp/gfx-tinykaboom-step4.png", frame)
}
func render(width, height int, fov float64) *Frame {
frame := NewFrame(width, height)
fw, fh := float64(width), float64(height)
for j := 0; j < height; j++ {
for i := 0; i < width; i++ {
fi, fj := float64(i), float64(j)
dir := gfx.V3((fi+0.5)-fw/2, -(fj+0.5)+fh/2, -fh/(2*math.Tan(fov/2)))
if hit, ok := sphereTrace(gfx.V3(0, 0, 3), dir.Norm()); ok {
ld := gfx.V3(10, 10, 10).Sub(hit).Norm()
li := math.Max(0.4, ld.Dot(distanceFieldNormal(hit)))
frame.Buffer[i+j*width] = gfx.V3(1, 1, 1).Mul(li)
} else {
frame.Buffer[i+j*width] = gfx.V3(0.1, 0.1, 0.1)
}
}
}
return frame
}
func signedDistance(p gfx.Vec3) float64 {
s := p.Norm().Mul(sphereRadius)
d := math.Sin(16*s.X) * math.Sin(16*s.Y) * math.Sin(16*s.Z) * noiseAmplitude
return p.SqLen() - sphereRadius + d
}
func sphereTrace(orig, dir gfx.Vec3) (gfx.Vec3, bool) {
pos := orig
for i := 0; i < 128; i++ {
d := signedDistance(pos)
if d < 0 {
return pos, true
}
pos = pos.Add(dir.Mul(math.Max(d*0.1, 0.01)))
}
return pos, false
}
func distanceFieldNormal(pos gfx.Vec3) gfx.Vec3 {
const eps = 0.1
d := signedDistance(pos)
nx := signedDistance(pos.Add(gfx.V3(eps, 0, 0))) - d
ny := signedDistance(pos.Add(gfx.V3(0, eps, 0))) - d
nz := signedDistance(pos.Add(gfx.V3(0, 0, eps))) - d
return gfx.V3(nx, ny, nz).Norm()
}
type Frame struct {
Buffer []gfx.Vec3
bounds image.Rectangle
gfx.Float64Scaler
}
func NewFrame(w, h int) *Frame {
return &Frame{
Buffer: make([]gfx.Vec3, w*h),
bounds: gfx.IR(0, 0, w, h),
Float64Scaler: gfx.NewLinearScaler().Domain(0, 1).Range(0, 255),
}
}
func (f *Frame) At(x, y int) color.Color {
v := f.Buffer[x+y*f.bounds.Max.X]
return color.NRGBA{
uint8(f.ScaleFloat64(v.X)),
uint8(f.ScaleFloat64(v.Y)),
uint8(f.ScaleFloat64(v.Z)),
255,
}
}
func (f *Frame) Bounds() image.Rectangle {
return f.bounds
}
func (f *Frame) ColorModel() color.Model {
return color.NRGBAModel
}
Step 5: one more implicit surface
package main
import (
"image"
"image/color"
"math"
"github.com/peterhellberg/gfx"
)
var (
sphereRadius = 1.0
noiseAmplitude = 0.9
)
func main() {
frame := render(640, 480, math.Pi/3.0)
gfx.SavePNG("/tmp/gfx-tinykaboom-step5.png", frame)
}
func render(width, height int, fov float64) *Frame {
frame := NewFrame(width, height)
fw, fh := float64(width), float64(height)
for j := 0; j < height; j++ {
for i := 0; i < width; i++ {
fi, fj := float64(i), float64(j)
dir := gfx.V3((fi+0.5)-fw/2, -(fj+0.5)+fh/2, -fh/(2*math.Tan(fov/2)))
if hit, ok := sphereTrace(gfx.V3(0, 0, 3), dir.Norm()); ok {
ld := gfx.V3(10, 10, 10).Sub(hit).Norm()
li := math.Max(0.4, ld.Dot(distanceFieldNormal(hit)))
frame.Buffer[i+j*width] = gfx.V3(1, 1, 1).Mul(li)
} else {
frame.Buffer[i+j*width] = gfx.V3(0.1, 0.1, 0.1)
}
}
}
return frame
}
func signedDistance(p gfx.Vec3) float64 {
d := math.Sin(8*p.X) * math.Sin(8*p.Y) * math.Sin(8*p.Z) * noiseAmplitude
return p.SqLen() - (sphereRadius + d)
}
func sphereTrace(orig, dir gfx.Vec3) (gfx.Vec3, bool) {
pos := orig
for i := 0; i < 256; i++ {
d := signedDistance(pos)
if d < 0 && pos.Z > 0 {
return pos, true
}
pos = pos.Add(dir.Mul(math.Max(d*0.1, 0.01)))
}
return pos, false
}
func distanceFieldNormal(pos gfx.Vec3) gfx.Vec3 {
const eps = 0.1
d := signedDistance(pos)
nx := signedDistance(pos.Add(gfx.V3(eps, 0, 0))) - d
ny := signedDistance(pos.Add(gfx.V3(0, eps, 0))) - d
nz := signedDistance(pos.Add(gfx.V3(0, 0, eps))) - d
return gfx.V3(nx, ny, nz).Norm()
}
type Frame struct {
Buffer []gfx.Vec3
bounds image.Rectangle
gfx.Float64Scaler
}
func NewFrame(w, h int) *Frame {
return &Frame{
Buffer: make([]gfx.Vec3, w*h),
bounds: gfx.IR(0, 0, w, h),
Float64Scaler: gfx.NewLinearScaler().Domain(0, 1).Range(0, 255),
}
}
func (f *Frame) At(x, y int) color.Color {
v := f.Buffer[x+y*f.bounds.Max.X]
return color.NRGBA{
uint8(f.ScaleFloat64(v.X)),
uint8(f.ScaleFloat64(v.Y)),
uint8(f.ScaleFloat64(v.Z)),
255,
}
}
func (f *Frame) Bounds() image.Rectangle {
return f.bounds
}
func (f *Frame) ColorModel() color.Model {
return color.NRGBAModel
}
Step 5: Animation
package main
import (
"image"
"image/color"
"math"
"github.com/peterhellberg/gfx"
)
var (
sphereRadius = 1.0
noiseAmplitude = 0.0
)
func main() {
a := &gfx.Animation{Delay: 25}
for _, na := range []float64{
.1, .2, .3, .4, .5, .6, .7, .6, .5, .4, .3, .2,
} {
noiseAmplitude = na
frame := render(640, 480, math.Pi/3.0)
p := gfx.NewPalettedImage(frame.Bounds(), gfx.PaletteEDG36[0:6])
gfx.DrawSrc(p, p.Bounds(), frame, gfx.ZP)
a.AddPalettedImage(p)
}
a.SaveGIF("/tmp/gfx-tinykaboom-step5-animation.gif")
}
func render(width, height int, fov float64) *Frame {
frame := NewFrame(width, height)
fw, fh := float64(width), float64(height)
for j := 0; j < height; j++ {
for i := 0; i < width; i++ {
fi, fj := float64(i), float64(j)
dir := gfx.V3((fi+0.5)-fw/2, -(fj+0.5)+fh/2, -fh/(2*math.Tan(fov/2)))
if hit, ok := sphereTrace(gfx.V3(0, 0, 3), dir.Norm()); ok {
ld := gfx.V3(10, 10, 10).Sub(hit).Norm()
li := math.Max(0.4, ld.Dot(distanceFieldNormal(hit)))
frame.Buffer[i+j*width] = gfx.V3(1, 1, 1).Mul(li)
} else {
frame.Buffer[i+j*width] = gfx.V3(0.1, 0.1, 0.1)
}
}
}
return frame
}
func signedDistance(p gfx.Vec3) float64 {
d := math.Sin(8*p.X) * math.Sin(8*p.Y) * math.Sin(8*p.Z) * noiseAmplitude
return p.SqLen() - (sphereRadius + d)
}
func sphereTrace(orig, dir gfx.Vec3) (gfx.Vec3, bool) {
pos := orig
for i := 0; i < 64; i++ {
d := signedDistance(pos)
if pos.Z <= 0 {
return pos, false
}
if d < 0 {
return pos, true
}
pos = pos.Add(dir.Mul(math.Max(d*0.1, 0.01)))
}
return pos, false
}
func distanceFieldNormal(pos gfx.Vec3) gfx.Vec3 {
const eps = 0.1
d := signedDistance(pos)
nx := signedDistance(pos.Add(gfx.V3(eps, 0, 0))) - d
ny := signedDistance(pos.Add(gfx.V3(0, eps, 0))) - d
nz := signedDistance(pos.Add(gfx.V3(0, 0, eps))) - d
return gfx.V3(nx, ny, nz).Norm()
}
type Frame struct {
Buffer []gfx.Vec3
bounds image.Rectangle
gfx.Float64Scaler
}
func NewFrame(w, h int) *Frame {
return &Frame{
Buffer: make([]gfx.Vec3, w*h),
bounds: gfx.IR(0, 0, w, h),
Float64Scaler: gfx.NewLinearScaler().Domain(0, 1).Range(0, 255),
}
}
func (f *Frame) At(x, y int) color.Color {
v := f.Buffer[x+y*f.bounds.Max.X]
return color.NRGBA{
uint8(f.ScaleFloat64(v.X)),
uint8(f.ScaleFloat64(v.Y)),
uint8(f.ScaleFloat64(v.Z)),
255,
}
}
func (f *Frame) Bounds() image.Rectangle {
return f.bounds
}
func (f *Frame) ColorModel() color.Model {
return color.NRGBAModel
}
Step 6: pseudorandom noise
package main
import (
"image"
"image/color"
"math"
"github.com/peterhellberg/gfx"
)
var (
sphereRadius = 1.5
noiseAmplitude = 1.0
simplex = gfx.NewSimplexNoise(0)
)
func main() {
frame := render(640, 480, math.Pi/3.0)
gfx.SavePNG("/tmp/gfx-tinykaboom-step6.png", frame)
}
func render(width, height int, fov float64) *Frame {
frame := NewFrame(width, height)
fw, fh := float64(width), float64(height)
for j := 0; j < height; j++ {
for i := 0; i < width; i++ {
fi, fj := float64(i), float64(j)
dir := gfx.V3((fi+0.5)-fw/2, -(fj+0.5)+fh/2, -fh/(2*math.Tan(fov/2)))
if hit, ok := sphereTrace(gfx.V3(0, 0, 3), dir.Norm()); ok {
ld := gfx.V3(10, 10, 10).Sub(hit).Norm()
li := math.Max(0.4, ld.Dot(distanceFieldNormal(hit)))
frame.Buffer[i+j*width] = gfx.V3(1, 1, 1).Mul(li)
} else {
frame.Buffer[i+j*width] = gfx.V3(0.1, 0.1, 0.1)
}
}
}
return frame
}
func rotate(v gfx.Vec3) gfx.Vec3 {
return gfx.V3(
gfx.V3(0.00, 0.80, 0.60).Dot(v),
gfx.V3(-0.80, 0.36, -0.48).Dot(v),
gfx.V3(-0.60, -0.48, 0.64).Dot(v),
)
}
func fractalBrownianMotion(x gfx.Vec3) float64 {
p := rotate(x)
f := 0.0
f += 0.5000 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(2.32)
f += 0.2500 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(3.03)
f += 0.1250 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(2.61)
f += 0.0625 * simplex.Noise3D(p.X, p.Y, p.Z)
return f / 0.9375
}
func signedDistance(p gfx.Vec3) float64 {
d := -fractalBrownianMotion(p.Mul(3.4)) * noiseAmplitude
return p.SqLen() - (sphereRadius + d)
}
func sphereTrace(orig, dir gfx.Vec3) (gfx.Vec3, bool) {
pos := orig
for i := 0; i < 256; i++ {
d := signedDistance(pos)
if d < 0 && pos.Z > 0 {
return pos, true
}
pos = pos.Add(dir.Mul(math.Max(d*0.1, 0.01)))
}
return pos, false
}
func distanceFieldNormal(pos gfx.Vec3) gfx.Vec3 {
const eps = 0.1
d := signedDistance(pos)
nx := signedDistance(pos.Add(gfx.V3(eps, 0, 0))) - d
ny := signedDistance(pos.Add(gfx.V3(0, eps, 0))) - d
nz := signedDistance(pos.Add(gfx.V3(0, 0, eps))) - d
return gfx.V3(nx, ny, nz).Norm()
}
type Frame struct {
Buffer []gfx.Vec3
bounds image.Rectangle
gfx.Float64Scaler
}
func NewFrame(w, h int) *Frame {
return &Frame{
Buffer: make([]gfx.Vec3, w*h),
bounds: gfx.IR(0, 0, w, h),
Float64Scaler: gfx.NewLinearScaler().Domain(0, 1).Range(0, 255),
}
}
func (f *Frame) At(x, y int) color.Color {
v := f.Buffer[x+y*f.bounds.Max.X]
return color.NRGBA{
uint8(f.ScaleFloat64(v.X)),
uint8(f.ScaleFloat64(v.Y)),
uint8(f.ScaleFloat64(v.Z)),
255,
}
}
func (f *Frame) Bounds() image.Rectangle {
return f.bounds
}
func (f *Frame) ColorModel() color.Model {
return color.NRGBAModel
}
Step 7: fire colors
package main
import (
"image"
"image/color"
"math"
"github.com/peterhellberg/gfx"
)
var (
sphereRadius = 1.5
noiseAmplitude = 1.5
simplex = gfx.NewSimplexNoise(42)
)
func main() {
frame := render(1920, 1080, math.Pi/3.0)
gfx.SavePNG("/tmp/gfx-tinykaboom-step7.png", frame)
}
func render(width, height int, fov float64) *Frame {
frame := NewFrame(width, height)
fw, fh := float64(width), float64(height)
for j := 0; j < height; j++ {
for i := 0; i < width; i++ {
fi, fj := float64(i), float64(j)
dir := gfx.V3((fi+0.5)-fw/2, -(fj+0.5)+fh/2, -fh/(2*math.Tan(fov/2)))
if hit, ok := sphereTrace(gfx.V3(0, 0, 3), dir.Norm()); ok {
noiseLevel := (sphereRadius - hit.SqLen()) / noiseAmplitude
ld := gfx.V3(10, 10, 10).Sub(hit).Norm()
li := math.Max(0.4, ld.Dot(distanceFieldNormal(hit)))
frame.Buffer[i+j*width] = paletteFire((-.2 + noiseLevel) * 2).Mul(li)
} else {
frame.Buffer[i+j*width] = gfx.V3(0.1, 0.1, 0.1)
}
}
}
return frame
}
func paletteFire(d float64) gfx.Vec3 {
var (
yellow = gfx.V3(1.7, 1.3, 1.0) // note that the color is "hot", i.e. has components >1
orange = gfx.V3(1.0, 0.6, 0.0)
red = gfx.V3(1.0, 0.0, 0.0)
darkgray = gfx.V3(0.2, 0.2, 0.2)
gray = gfx.V3(0.4, 0.4, 0.4)
)
x := math.Max(0, math.Min(1, d))
switch {
case x < 0.25:
return gray.Lerp(darkgray, x*4)
case x < 0.5:
return darkgray.Lerp(red, x*4-1)
case x < 0.75:
return red.Lerp(orange, x*4-2)
default:
return orange.Lerp(yellow, x*4-3)
}
}
func rotate(v gfx.Vec3) gfx.Vec3 {
return gfx.V3(
gfx.V3(0.00, 0.80, 0.60).Dot(v),
gfx.V3(-0.80, 0.36, -0.48).Dot(v),
gfx.V3(-0.60, -0.48, 0.64).Dot(v),
)
}
func fractalBrownianMotion(x gfx.Vec3, f float64) float64 {
p := rotate(x)
f += 0.5000 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(2.32)
f += 0.2500 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(3.03)
f += 0.1250 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(2.61)
f += 0.0625 * simplex.Noise3D(p.X, p.Y, p.Z)
return f
}
func signedDistance(p gfx.Vec3) float64 {
d := -fractalBrownianMotion(p.Mul(1.4), 0.5) * noiseAmplitude
return p.SqLen() - (sphereRadius + d)
}
func sphereTrace(orig, dir gfx.Vec3) (gfx.Vec3, bool) {
pos := orig
for i := 0; i < 256; i++ {
d := signedDistance(pos)
if d < 0 && pos.Z > 0 {
return pos, true
}
pos = pos.Add(dir.Mul(math.Max(d*0.1, 0.01)))
}
return pos, false
}
func distanceFieldNormal(pos gfx.Vec3) gfx.Vec3 {
const eps = 0.1
d := signedDistance(pos)
nx := signedDistance(pos.Add(gfx.V3(eps, 0, 0))) - d
ny := signedDistance(pos.Add(gfx.V3(0, eps, 0))) - d
nz := signedDistance(pos.Add(gfx.V3(0, 0, eps))) - d
return gfx.V3(nx, ny, nz).Norm()
}
type Frame struct {
Buffer []gfx.Vec3
bounds image.Rectangle
gfx.Float64Scaler
}
func NewFrame(w, h int) *Frame {
return &Frame{
Buffer: make([]gfx.Vec3, w*h),
bounds: gfx.IR(0, 0, w, h),
Float64Scaler: gfx.NewLinearScaler().Domain(0, 1).Range(0, 255),
}
}
func (f *Frame) At(x, y int) color.Color {
v := f.Buffer[x+y*f.bounds.Max.X]
return color.NRGBA{
uint8(f.ScaleFloat64(gfx.Clamp(v.X, 0, 1))),
uint8(f.ScaleFloat64(gfx.Clamp(v.Y, 0, 1))),
uint8(f.ScaleFloat64(gfx.Clamp(v.Z, 0, 1))),
255,
}
}
func (f *Frame) Bounds() image.Rectangle {
return f.bounds
}
func (f *Frame) ColorModel() color.Model {
return color.NRGBAModel
}
3840x2160
Optimized
package main
import (
"image"
"image/color"
"math"
"github.com/peterhellberg/gfx"
)
var (
sphereRadius = 1.5
noiseAmplitude = 1.5
simplex = gfx.NewSimplexNoise(42)
bg = gfx.V3(0.1, 0.1, 0.1)
orig = gfx.V3(0, 0, 3)
lv = gfx.V3(10, 10, 10)
)
func main() {
frame := render(1920, 1080, math.Pi/3.0)
gfx.SavePNG("/tmp/gfx-tinykaboom-step7-optimized.png", frame)
}
func render(width, height int, fov float64) *Frame {
var (
frame = NewFrame(width, height)
fw, fh = float64(width), float64(height)
fw2, fh2 = fw / 2, fh / 2
fhtf2 = -fh / (2 * math.Tan(fov/2))
)
for j := 0; j < height; j++ {
for i := 0; i < width; i++ {
fi, fj := float64(i), float64(j)
dir := gfx.V3((fi+0.5)-fw2, -(fj+0.5)+fh2, fhtf2).Norm()
if hit, ok := sphereTrace(orig, dir); ok {
noiseLevel := (sphereRadius - hit.SqLen()) / noiseAmplitude
li := math.Max(0.4, lv.Sub(hit).Norm().Dot(distanceFieldNormal(hit)))
frame.Buffer[i+j*width] = paletteFire((-0.2 + noiseLevel) * 2).Mul(li)
} else {
frame.Buffer[i+j*width] = bg
}
}
}
return frame
}
var (
yellow = gfx.V3(1.7, 1.3, 1.0) // note that the color is "hot", i.e. has components >1
orange = gfx.V3(1.0, 0.6, 0.0)
red = gfx.V3(1.0, 0.0, 0.0)
darkgray = gfx.V3(0.2, 0.2, 0.2)
gray = gfx.V3(0.4, 0.4, 0.4)
)
func paletteFire(d float64) gfx.Vec3 {
x := math.Max(0, math.Min(1, d))
switch {
case x < 0.25:
return gray.Lerp(darkgray, x*4)
case x < 0.5:
return darkgray.Lerp(red, x*4-1)
case x < 0.75:
return red.Lerp(orange, x*4-2)
default:
return orange.Lerp(yellow, x*4-3)
}
}
func rotate(v gfx.Vec3) gfx.Vec3 {
return gfx.V3(
gfx.V3(0.00, 0.80, 0.60).Dot(v),
gfx.V3(-0.80, 0.36, -0.48).Dot(v),
gfx.V3(-0.60, -0.48, 0.64).Dot(v),
)
}
func fractalBrownianMotion(x gfx.Vec3, f float64) float64 {
p := rotate(x)
f += 0.5000 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(2.32)
f += 0.2500 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(3.03)
f += 0.1250 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(2.61)
f += 0.0625 * simplex.Noise3D(p.X, p.Y, p.Z)
return f
}
func signedDistance(p gfx.Vec3) float64 {
d := -fractalBrownianMotion(p.Mul(1.4), 0.5) * noiseAmplitude
return p.SqLen() - (sphereRadius + d)
}
func sphereTrace(orig, dir gfx.Vec3) (gfx.Vec3, bool) {
if orig.SqLen()-math.Pow(orig.Dot(dir), 2) > math.Pow(sphereRadius, 2) {
return orig, false
}
pos := orig
for i := 0; i < 64; i++ {
d := signedDistance(pos)
if d < 0 && pos.Z > 0 {
return pos, true
}
pos = pos.Add(dir.Mul(math.Max(d*0.1, 0.01)))
}
return pos, false
}
const eps = 0.1
var (
epsX = gfx.V3(eps, 0, 0)
epsY = gfx.V3(0, eps, 0)
epsZ = gfx.V3(0, 0, eps)
)
func distanceFieldNormal(pos gfx.Vec3) gfx.Vec3 {
d := signedDistance(pos)
return gfx.V3(
signedDistance(pos.Add(epsX))-d,
signedDistance(pos.Add(epsY))-d,
signedDistance(pos.Add(epsZ))-d,
).Norm()
}
type Frame struct {
Buffer []gfx.Vec3
bounds image.Rectangle
gfx.Float64Scaler
}
func NewFrame(w, h int) *Frame {
return &Frame{
Buffer: make([]gfx.Vec3, w*h),
bounds: gfx.IR(0, 0, w, h),
Float64Scaler: gfx.NewLinearScaler().Domain(0, 1).Range(0, 255),
}
}
func (f *Frame) At(x, y int) color.Color {
v := f.Buffer[x+y*f.bounds.Max.X]
return color.NRGBA{
uint8(f.ScaleFloat64(gfx.Clamp(v.X, 0, 1))),
uint8(f.ScaleFloat64(gfx.Clamp(v.Y, 0, 1))),
uint8(f.ScaleFloat64(gfx.Clamp(v.Z, 0, 1))),
255,
}
}
func (f *Frame) Bounds() image.Rectangle {
return f.bounds
}
func (f *Frame) ColorModel() color.Model {
return color.NRGBAModel
}
Ebiten version: https://jsgo.io/9c895916adc7fa50128f9695bd697dab2ea88537
package main
import (
"image"
"image/color"
"math"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil"
"github.com/peterhellberg/gfx"
)
var (
simplex = gfx.NewSimplexNoise(42)
bg = gfx.V3(0.1, 0.1, 0.1)
orig = gfx.V3(0, 0, 3)
lv = gfx.V3(10, 10, 10)
)
var (
yellow = gfx.V3(1.7, 1.3, 1.0) // note that the color is "hot", i.e. has components >1
orange = gfx.V3(1.0, 0.6, 0.0)
red = gfx.V3(1.0, 0.0, 0.0)
darkgray = gfx.V3(0.2, 0.2, 0.2)
gray = gfx.V3(0.4, 0.4, 0.4)
)
func main() {
s := &State{
width: 192,
height: 108,
fov: math.Pi / 3.0,
sr: 1.5,
na: 1.5,
}
s.render()
ebiten.SetFullscreen(true)
ebiten.Run(s.loop, s.width, s.height, 10, "Ebiten GFX Tinyboom")
}
type State struct {
width int
height int
fov float64
sr float64
na float64
dirty bool
frame *Frame
}
func (s *State) render() {
s.frame = render(s.width, s.height, s.fov, s.sr, s.na)
s.dirty = false
}
func (s *State) loop(screen *ebiten.Image) error {
if ebiten.IsKeyPressed(ebiten.KeyEscape) || ebiten.IsKeyPressed(ebiten.KeyQ) {
return gfx.ErrDone
}
switch {
case ebiten.IsKeyPressed(ebiten.KeyUp):
s.na -= 0.02
s.dirty = true
case ebiten.IsKeyPressed(ebiten.KeyDown):
s.na += 0.02
s.dirty = true
case ebiten.IsKeyPressed(ebiten.KeyRight):
s.sr += 0.02
s.dirty = true
case ebiten.IsKeyPressed(ebiten.KeyLeft):
s.sr -= 0.02
s.dirty = true
}
if ebiten.IsDrawingSkipped() {
return nil
}
if s.dirty {
gfx.Dump(s)
s.render()
}
screen.ReplacePixels(s.frame.Pix)
return ebitenutil.DebugPrint(screen, gfx.Sprintf("r:%.02f a:%.02f", s.sr, s.na))
}
func render(width, height int, fov, sr, na float64) *Frame {
var (
frame = NewFrame(width, height)
fw, fh = float64(width), float64(height)
fw2, fh2 = fw / 2, fh / 2
fhtf2 = -fh / (2 * math.Tan(fov/2))
)
for j := 0; j < height; j++ {
for i := 0; i < width; i++ {
fi, fj := float64(i), float64(j)
dir := gfx.V3((fi+0.5)-fw2, -(fj+0.5)+fh2, fhtf2).Norm()
if hit, ok := sphereTrace(orig, dir, sr, na); ok {
noiseLevel := (sr - hit.SqLen()) / na
li := math.Max(0.4, lv.Sub(hit).Norm().Dot(distanceFieldNormal(hit, sr, na)))
c := paletteFire((-0.2 + noiseLevel) * 2).Mul(li)
frame.Buffer[i+j*width] = gfx.V3(
gfx.Clamp(c.X, 0, 1),
gfx.Clamp(c.Y, 0, 1),
gfx.Clamp(c.Z, 0, 1),
)
} else {
frame.Buffer[i+j*width] = bg
}
}
}
f := gfx.NewImage(width, height)
gfx.DrawSrc(f, f.Bounds(), frame, gfx.ZP)
frame.Pix = f.Pix
return frame
}
func paletteFire(d float64) gfx.Vec3 {
x := math.Max(0, math.Min(1, d))
switch {
case x < 0.25:
return gray.Lerp(darkgray, x*4)
case x < 0.5:
return darkgray.Lerp(red, x*4-1)
case x < 0.75:
return red.Lerp(orange, x*4-2)
default:
return orange.Lerp(yellow, x*4-3)
}
}
func rotate(v gfx.Vec3) gfx.Vec3 {
return gfx.V3(
gfx.V3(0.00, 0.80, 0.60).Dot(v),
gfx.V3(-0.80, 0.36, -0.48).Dot(v),
gfx.V3(-0.60, -0.48, 0.64).Dot(v),
)
}
func fractalBrownianMotion(x gfx.Vec3, f float64) float64 {
p := rotate(x)
f += 0.5000 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(2.32)
f += 0.2500 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(3.03)
f += 0.1250 * simplex.Noise3D(p.X, p.Y, p.Z)
p = p.Mul(2.61)
f += 0.0625 * simplex.Noise3D(p.X, p.Y, p.Z)
return f
}
func signedDistance(p gfx.Vec3, sr, na float64) float64 {
d := -fractalBrownianMotion(p.Mul(1.4), 0.5) * na
return p.SqLen() - (sr + d)
}
func sphereTrace(orig, dir gfx.Vec3, sr, na float64) (gfx.Vec3, bool) {
if orig.SqLen()-math.Pow(orig.Dot(dir), 2) > math.Pow(sr, 2) {
return orig, false
}
pos := orig
for i := 0; i < 64; i++ {
d := signedDistance(pos, sr, na)
if d < 0 && pos.Z > 0 {
return pos, true
}
pos = pos.Add(dir.Mul(math.Max(d*0.1, 0.01)))
}
return pos, false
}
const eps = 0.1
var (
epsX = gfx.V3(eps, 0, 0)
epsY = gfx.V3(0, eps, 0)
epsZ = gfx.V3(0, 0, eps)
)
func distanceFieldNormal(pos gfx.Vec3, sr, na float64) gfx.Vec3 {
d := signedDistance(pos, sr, na)
return gfx.V3(
signedDistance(pos.Add(epsX), sr, na)-d,
signedDistance(pos.Add(epsY), sr, na)-d,
signedDistance(pos.Add(epsZ), sr, na)-d,
).Norm()
}
type Frame struct {
Buffer []gfx.Vec3
Pix []uint8
bounds image.Rectangle
}
func NewFrame(w, h int) *Frame {
return &Frame{
Buffer: make([]gfx.Vec3, w*h),
Pix: make([]uint8, w*h*4),
bounds: gfx.IR(0, 0, w, h),
}
}
func (f *Frame) At(x, y int) color.Color {
v := f.Buffer[x+y*f.bounds.Max.X]
return color.NRGBA{uint8(v.X * 255), uint8(v.Y * 255), uint8(v.Z * 255), 255}
}
func (f *Frame) Bounds() image.Rectangle {
return f.bounds
}
func (f *Frame) ColorModel() color.Model {
return color.NRGBAModel
}
| r 1.50 a 1.50 | r 3.12 a 3.96 | r 1.46 a -9.80 |
|---|---|---|
 |
 |
 |
| r 6.44 a -0.02 | r 2.10 a -1.20 | r 6.66 a 6.66 |
|---|---|---|
 |
 |
 |
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Step 2: diffuse lighting