Natalia Berdys: Random Talk: The Consistent World of Noise

Bio:
Natalia Berdys is an independent iOS developer from Poland. Within 2 years, she managed to become a self-taught developer, get a Mobile Engineering degree, speak at Apple WWDC and take her apps to #1 in 47 countries. Since she also holds a Master's Degree in American Literature, she has a very humanistic and poetic view of programming. Previously with Tutu Lab, now evolving into her next form.

Abstract:
Chance permeates our human existence - but it’s our instinct to seek order in chaos. In this talk, we’ll explore the fishy realm of randomness, and when it’s just too unnatural for our apps - let’s bend it to our will by making it evolve into coherent patterns with the GameplayKit framework. We’ll use the latest iOS 10 APIs and procedural noise to generate harmonious digital worlds, landscapes and textures - a comforting way to mine some creativity from silicon chips.

Twitter: https://twitter.com/batalia

Transcript

1. RANDOM TALK: THE CONSISTENT WORLD OF NOISE
3. Which is random? ⚪""⚪"⚪"⚪""⚪"⚪"""⚪⚪""⚪"⚪⚪"""⚪"⚪⚪⚪ or ⚪⚪"⚪⚪""⚪"⚪⚪⚪⚪⚪"⚪⚪""⚪⚪"⚪⚪⚪⚪⚪⚪⚪⚪""
4. WHICH IS RANDOM? 1 ⚪""⚪"⚪"⚪""⚪"⚪"""⚪⚪""⚪"⚪⚪"""⚪"⚪⚪⚪ OR ⚪⚪"⚪⚪""⚪"⚪⚪⚪⚪⚪"⚪⚪""⚪⚪"⚪⚪⚪⚪⚪⚪⚪⚪"" 1 Barrow, John D. (2008). 100 Essential Things You Didn't Know You Didn't Know.
5. PATTERNS EVERYWHERE
6. let randomness: Bool
7. True random number generators > method: ! (" ☢ $) > uniform: ✅ > independent: ✅ Pseudo-random number generators > method: ! "
   > uniform: ✅ > independent: ❌ %
8. Pseudo-random number generator
9. That's, like, so pseudo-random.
10. Random numbers should not be generated with a method chosen at random — Donald Knuth
12. GKRandomSource
13. LINEAR CONGRUENTIAL RANDOM NUMBER GENERATOR let randomSource = GKLinearCongruentialRandomSource() Fast, but biased
14. THE MERSENNE TWISTER let randomSource = GKMersenneTwisterRandomSource() Period: Slower, but more random
15. THE ARC4 let randomSource = GKARC4RandomSource() Implements the ARC4 algorithm Independent from arc4random family. Middle ground between speed and randomness.
16. SHUFFLING
17. SHUFFLING let fruitDeck = ["!", """, "#", "$"] let shuffledDeck = GKARC4RandomSource.sharedRandom() .arrayByShufflingObjects(in: fruitDeck) ! " # $
19. We're making it less random to make it feel more random — Steve Jobs
20. DISTRIBUTION
21. GAMEPLAYKIT GKGaussianDistribution GKShuffledDistribution GKRandomDistribution
22. GAUSSIAN (NORMAL) DISTRIBUTION
23. let ! = GKGaussianDistribution.d6() for roll in 1...6 { !.nextInt() } ⚃ ⚄ ⚃ ⚃ ⚂ ⚂
24. let ! = GKShuffledDistribution.d6() for roll in 1...6 { !.nextInt() } ⚅ ⚁ ⚃ ⚀ ⚂ ⚄
25. let ! = GKRandomDistribution.d6() for roll in 1...6 { !.nextInt() } ⚀ ⚀ ⚀ ⚅ ⚄ ⚄
26. Random distribution of size let random = GKRandomDistribution(lowestValue: 3, highestValue: 10) raccoon.setScale = CGFloat(random.nextInt()) * 0.1
27. Gaussian distribution of size let gaussian = GKGaussianDistribution(lowestValue: 3, highestValue: 10) raccoon.setScale = CGFloat(gaussian.nextInt()) * 0.1
28. RANDOM DISTRIBUTION OF SPEED let random = GKRandomDistribution(lowestValue: 10, highestValue: 25) for ufo in ufoNode.children { ufo.run(SKAction.moveTo(y: -1500, duration: TimeInterval(random.nextInt()))) }
29. GAUSSIAN DISTRIBUTION OF SPEED let gaussian = GKGaussianDistribution(lowestValue: 10, highestValue: 25) for ufo in ufoNode.children { ufo.run(SKAction.moveTo(y: -1500, duration: TimeInterval(gaussian.nextInt()))) }
30. RANDOM
31. ?
32. PROCEDURAL NOISE
33. PERLIN NOISE
34. 1D PERLIN NOISE
35. 2D PERLIN NOISE
36. 3D PERLIN NOISE
37. GKNoiseSource ! GKPerlinNoiseSource ⛰ GKRidgedNoiseSource # GKBillowNoiseSource $ GKVoronoiNoiseSource % GKCylindersNoiseSource & GKSpheresNoiseSource ' GKCheckerboardNoiseSource 㽪 GKConstantNoiseSource
38. let noiseSource = GKPerlinNoiseSource() let noise = GKNoise(noiseSource:noiseSource)
39. noiseSource.octaveCount = 1 3 6
40. noiseSource.frequency = 1 2 4
41. ADJUST NOISE PARAMETERS let noiseSource = GKPerlinNoiseSource() noiseSource.frequency = 1 noiseSource.octaveCount = 6 noiseSource.lacunarity = 2 noiseSource.persistence = 0.5 let noise = GKNoise(noiseSource:noiseSource)
42. ADD COLOR let noiseSource = GKPerlinNoiseSource() let noise = GKNoise(noiseSource:noiseSource) noise.gradientColors = [-1 : !, 0 : ", 1 : ⚪] MAP TO TEXTURE let map = GKNoiseMap(noise: noise) let sprite = SKSpriteNode(texture: SKTexture(noiseMap: map))
43. YOU CAN: > apply operations to noise values > combine noise objects > distort noise > apply geometric transformations
44. ANIMATION let moveMap = SKAction.run { map = GKNoiseMap(noise: noise, size: vector2(2, 2), origin: (vector2(map.origin.x+0.01, 0)), sampleCount: vector2(300, 300), seamless: false) sprite.texture = SKTexture(noiseMap: map) } let moveMapForever = SKAction.repeatForever( (SKAction.sequence([moveMap, SKAction.wait(forDuration: 0.1)]))) sprite.run(moveMapForever)
45. noise.move(by: (vector3(0.0, 0.01, 0.0))) let newMap = GKNoiseMap(noise: noise) let newTexture = SKTexture(noiseMap: newMap) sprite.texture = newTexture sprite2.texture = newTexture
46. myCamera.position.x = CGFloat(noise.value(atPosition: (vector2(Float(waveStep), 0))))*100 myCamera.position.y = CGFloat(noise.value(atPosition: (vector2(0, Float(waveStep)))))*100 waveStep += 0.01
47. let timeStep = waveStep/3 + 0.3 * sin(M_2_PI * waveStep/3) let eyeBallFactorX = CGFloat( noiseHead.value(atPosition: (vector2(Float(timeStep), 0)))) let eyeBallFactorY = CGFloat( noiseHead.value(atPosition: (vector2(Float(timeStep+10)/2, 0))))
48. GKRidgedNoiseSource let source = GKRidgedNoiseSource() source.lacunarity = 2 source.frequency = 3 source.octaveCount = 6 noise.move(by: (vector3(0.0, 0.01, 0.0)
49. GKRidgedNoiseSource let source = GKRidgedNoiseSource() source.lacunarity = 2 source.frequency = 3 source.octaveCount = 6 noise.move(by: (vector3(0.0, 0.01, 0.0)
50. GKRidgedNoiseSource
51. GKVoronoiNoiseSource
52. GKCylindersNoiseSource
53. BIOMES
54. COMBINING NOISE: HEIGHT MAP let combinedNoise = GKNoise( componentNoises: [noiseWater, noiseSand, noiseTrees, noiseMountains], selectionNoise: ridgedNoise, componentBoundaries: [-0.7, -0.6 ,0.5], boundaryBlendDistances: [0, 0.1, 0.3])
55. USE WITH SCENEKIT let ball = SCNSphere(radius: 100) let materials = SCNMaterial() materials.locksAmbientWithDiffuse = true materials.diffuse.contents = UIImage(cgImage: (spriteCombined. texture?.cgImage())!) ball.firstMaterial = materials ball.isGeodesic = true
56. GKPerlinNoiseSource GKRidgedNoiseSource
58. DETERMINISM !"
59. !
60. ACKNOWLEDGEMENTS: SOME GRAPHICS PROVIDED BY VECTEEZY.COM. 3D TEXTURE - PERLIN NOISE IMAGE BY AERON203 CC BY 3.0. SOURCES/FURTHER READING: Barrow, John D. (2008). 100 Essential Things You Didn't Know You Didn't Know. London: The Bodley Head. Mlodinow, Leonard (2008). The Drunkard's Walk: How Randomness Rules Our Lives. New York: Pantheon Books.
61. THANK YOU! NATALIA BERDYS @BATALIA TRY! SWIFT NYC 2016