空の色を計算してみた/calculate-sky-color

1. ՆٳΈͷࣗ༝ݚڀ ۭͷ৭ΛܭࢉͰٻΊͯΈΔ 2021/08/13 Ԭຊᕣฏ
2. ࣗݾ঺հɿԬຊ ᕣฏ • ࠇഎܠͷεϥΠυॳ௅ઓͰυΩυΩͯ͠·͢ • େֶ͸Խֶ΍ͬͯ·ͨ͠ • લ৬͸ۚ༥ܥͷγεςϜ࡞ͬͯ·ͨ͠ • ࠓ͸OESͷWebνʔϜͰ։ൃ͍ͯ͠·͢ • go࢖ͬͨ͜ͱͳ͍ίϯϓϨοΫεͩͬͨͷͰɺࠓճ͸͸͡ΊͯgoΛ ৮ͬͯΈ·ͨ͠ (ͱ͍͍ͭͭɺ͓୊తʹશવίʔυॻ͍ͯ·ͤΜw)
4. ;ͱؾʹͳͬͨ ۭͷ৭ͬͯԿ৭ͩΖ͏ɾɾɾʁ
5. ͦ΋ͦ΋ɺۭͬͯͳΜͰݟ͑Δͷʁ • ۭؾத͸͍͍ͩͨ஠ૉͱࢎૉ͔ΒͰ͖͍ͯ·͢ɻ • ஠ૉͱࢎૉ͕ଠཅͷޫΛࢄཚ͠·͢ɻ • ͦͷࢄཚͷ࢓૊ΈΛϨΠϦʔࢄཚͱ͍͍·͢ɻ
6. ͦ΋ͦ΋ɺۭͬͯͳΜͰݟ͑Δͷʁ • ۭؾத͸͍͍ͩͨ஠ૉͱࢎૉ͔ΒͰ͖͍ͯ·͢ɻ • ஠ૉͱࢎૉ͕ଠཅͷޫΛࢄཚ͠·͢ɻ • ͦͷࢄཚͷ࢓૊ΈΛϨΠϦʔࢄཚͱ͍͍·͢ɻ • ͳͷͰɺۭؾ͕ͳ͍ͱۭ͸ࠇ͍Ͱ͢ɻ
7. ࢄཚʹ΋͍Ζ͍Ζ (ͪΐͬͱ୤ઢ) • ϨΠϦʔࢄཚ • ޫͷ೾௕ΑΓ΋ࡉཻ͔͍ࢠʹର͢Δࢄཚ • ࠓճ͸ͬͪ͜ • ϛʔࢄཚ • ޫͷ೾௕ΑΓ΋େཻ͖͍ࢠʹର͢Δࢄཚ • લํ΁ͷࢄཚͷ೾௕ґଘੑ͕গͳ͍ɻͷͰɺશ෦ͷޫ͕ࢄཚ͞ΕͯӢ ͸ന͘Έ͑·͢ɻ
8. ࠓճͷΞϓϩʔν 1. ଠཅޫͷR / G / BͷޫͷॏͶ߹Θͤͱͯۙ͠ࣅ͢Δɻ 2. R / G / BͦΕͧΕࢄཚ͞ΕΔޫͷ૬ର஋Λܭࢉ͢Δ 3. RGB஋ʹ্هͰٻΊͨ૬ର஋Λೖྗ͢Δ 4. ্هͱ୯೾௕ͷޫΛݟൺ΂͍͍ͯͩͨͷ೾௕ΛٻΊͯΈΔ
9. ࠓճͷΞϓϩʔν 1. ଠཅޫͷR / G / BͷޫͷॏͶ߹Θͤͱͯۙ͠ࣅ͢Δɻ 2. R / G / BͦΕͧΕࢄཚ͞ΕΔޫͷ૬ର஋Λܭࢉ͢Δ 3. RGB஋ʹ্هͰٻΊͨ૬ର஋Λೖྗ͢Δ 4. ্هͱ୯೾௕ͷޫΛݟൺ΂͍͍ͯͩͨͷ೾௕ΛٻΊͯΈΔ
10. RGB͸͍͍ͩͨ 6 : 7 : 8͘Β͍ɾɾɾʁ ग़యɿhttps://www.fondriest.com/environmental-measurements/
11. ࠓճͷΞϓϩʔν 1. ଠཅޫͷR / G / BͷޫͷॏͶ߹Θͤͱͯۙ͠ࣅ͢Δɻ 2. R / G / BͦΕͧΕࢄཚ͞ΕΔޫͷ૬ର஋Λܭࢉ͢Δ 3. RGB஋ʹ্هͰٻΊͨ૬ର஋Λೖྗ͢Δ 4. ্هͱ୯೾௕ͷޫΛݟൺ΂͍͍ͯͩͨͷ೾௕ΛٻΊͯΈΔ
12. I = kN(n − 1)2 λ4 ϨΠϦʔࢄཚʹΑΔࢄཚڧ౓ k : ൺྫఆ਺ɺN : ෼ࢠ਺ɺn : ۶ં཰ɺЕ: ೾௕
13. ࠓճ͸૬ର஋͕΄͍͠ͷͰɺద౰ʹఆ਺Λ͔͚ͨ type Light struct { Wavelength in t Intensity in t } func scatteredLight(light Light) Light { return Light{light.Wavelength, light.Intensity << 40 / (light.Wavelength * light.Wavelength * light.Wavelength * light.Wavelength) } }
14. ͜Μͳײ͡Ͱग़ྗͯ͠RGB஋Λऔಘ red := Light{700, 6 } green := Light{546, 7 } blue := Light{436, 8 } fmt.Println("sky color!!" ) fmt.Println("red: ", scatteredLight(red) ) fmt.Println("green: ", scatteredLight(green) ) fmt.Println("blue: ", scatteredLight(blue))
15. ͜Μͳײ͡Ͱग़ྗͯ͠RGB஋Λऔಘ red := Light{700, 6 } green := Light{546, 7 } blue := Light{436, 8 } fmt.Println("sky color!!" ) fmt.Println("red: ", scatteredLight(red) ) fmt.Println("green: ", scatteredLight(green) ) fmt.Println("blue: ", scatteredLight(blue))
16. ࠓճͷΞϓϩʔν 1. ଠཅޫͷR / G / BͷޫͷॏͶ߹Θͤͱͯۙ͠ࣅ͢Δɻ 2. R / G / BͦΕͧΕࢄཚ͞ΕΔޫͷ૬ର஋Λܭࢉ͢Δ 3. RGB஋ʹ্هͰٻΊͨ૬ର஋Λೖྗ͢Δ 4. ্هͱ୯೾௕ͷޫΛݟൺ΂͍͍ͯͩͨͷ೾௕ΛٻΊͯΈΔ
17. #1B56F3
18. ࠓճͷΞϓϩʔν 1. ଠཅޫͷR / G / BͷޫͷॏͶ߹Θͤͱͯۙ͠ࣅ͢Δɻ 2. R / G / BͦΕͧΕࢄཚ͞ΕΔޫͷ૬ର஋Λܭࢉ͢Δ 3. RGB஋ʹ্هͰٻΊͨ૬ର஋Λೖྗ͢Δ 4. ্هͱ୯೾௕ͷޫΛݟൺ΂͍͍ͯͩͨͷ೾௕ΛٻΊͯΈΔ
19. 430nm #3D00FF #1B56F3 440nm #0000FF 450nm #0046FF 460nm #007BFF
20. 430nm #3D00FF 440nm #0000FF 450nm #0046FF 460nm #007BFF ͍͍ͩͨ͜Ε͘Β͍ #1B56F3
21. 450nm #0046FF ͍͍ͩͨ͜Ε͘Β͍ #1B56F3
22. ۭ৭ #89BDDE 450nm #0046FF ͍͍ͩͨ͜Ε͘Β͍ #1B56F3
23. ·ͱΊ • ݁ߏࡶʹܭࢉͯͦ͠ΕͬΆ͍ײ͡ͷ৭͸ಋग़Ͱ͖ͯײಈɻ • #1B56F3ɺ͍͍ͩͨ450nm • ্ۭͷۭͷ৭͸݁ߏͦΕͬΆ͍৭ʹͳͬͯΔͷͰ͸ɻ • ͪͳΈʹνϦͳͲ͕ଟ͍೔͸բΜͰനͬΆ͘ͳΓ·͢ɻ • ͍ͭͰʹ(?) goͷνϡʔτϦΞϧ΋͜ΕΛػʹͰ͖ͯΑ͔ͬͨɻ #1B56F3