{"id":66,"date":"2013-05-06T11:50:44","date_gmt":"2013-05-06T18:50:44","guid":{"rendered":"http:\/\/www.imaginary-institute.com\/blog\/?p=66"},"modified":"2013-05-06T16:27:50","modified_gmt":"2013-05-06T23:27:50","slug":"66","status":"publish","type":"post","link":"https:\/\/www.imaginary-institute.com\/blog\/2013\/05\/06\/66\/","title":{"rendered":"Circles, Nomads, and A Running Course"},"content":{"rendered":"
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Nomads starting on circles, then finding their own way in life<\/p><\/div>\n

My 2D graphics course<\/a> went live today! It was hot here last night so I slept on the couch downstairs, and by coincidence my dog woke me up around 12:30. Since the course materials were supposed to appear on the site at midnight, I checked – and there they were! So everything seems smooth so far, and I’ve had no complaints from students.<\/p>\n

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More Nomads, searching for fulfillment<\/p><\/div>\n

To celebrate, I decided to make something pretty. I wrote this program for making little splindly-yarn things. Here are a few images I just made. It’s fun to play with this – I could sit here making little things like this all day!<\/p>\n

Here’s the code. If you’re in my class, you’ll find all of this easy to understand by the time we’re done.
\n<\/p>\n

\/\/ Circle Nomads \r\n\/\/ Andrew Glassner, 5 May 2013\r\n\/\/ We start with a single circle of Nomads. Click the\r\n\/\/ mouse to start a new one, centered at the mouse.\r\nNomad[] NomadList;\r\nint StepCount;\r\nint MaxSteps;\r\nboolean Frozen = false;\r\nfloat NoiseScale;\r\n\r\nvoid setup() {\r\n  size(800, 600);\r\n  smooth();\r\n  \/\/ Start with one burst in a random place\r\n  initNomads(random(0,width), random(0,height));\r\n  background(0);\r\n}\r\n\r\n\/\/ Create a circle of Nomads. Each one is randomly on the\r\n\/\/ circle, and has some variation of the shared color.\r\nvoid initNomads(float diskX, float diskY) {\r\n  NomadList = new Nomad[300];\r\n  float diskR = random(25, 100);\r\n  colorMode(HSB);\r\n    color baseClr = color(random(0,255), random(100,255), random(170,255));\r\n  colorMode(RGB);\r\n  for (int i=0; i<300; i++) {\r\n    float angle = random(0, TWO_PI);\r\n    color thisClr = wiggleColorHSB(baseClr, .1, .1, .1);\r\n    NomadList[i] = new Nomad(diskX+(diskR*cos(angle)),\r\n                             diskY+(diskR*sin(angle)), thisClr, 1);\r\n  }\r\n  StepCount = 0;\r\n  MaxSteps = int(random(200, 800)); \/\/ how many times to draw\r\n  \/\/ low values of noise give long, thin tendrils. High values are twistier.\r\n  NoiseScale = random(.0001, .03);\r\n} \r\n\r\n\/\/ given an HSB color, wiggle each of the values around a bit\r\ncolor wiggleColorHSB(color c, float wh, float ws, float wb) {\r\n  colorMode(HSB);\r\n    float newHue = (hue(c)+(wh*255*random(-1, 1))) % 255;\r\n    float newSat = constrain(saturation(c)+(ws*255*random(-1,1)), 0, 255);\r\n    float newBrt = constrain(brightness(c)+(wb*255*random(-1,1)), 0, 255);\r\n    color newClr = color(newHue, newSat, newBrt);\r\n  colorMode(RGB);\r\n  return(newClr);\r\n}\r\n\r\nvoid draw() {\r\n  if (Frozen) return;\r\n  if (++StepCount > MaxSteps) {\r\n    return;\r\n  }\r\n  for (int i=0; i<NomadList.length; i++) {\r\n    NomadList[i].render();\r\n    NomadList[i].update();\r\n  }\r\n}\r\n\r\nvoid keyTyped() {\r\n  if (key == ' ') Frozen = !Frozen;\r\n} \r\n\r\nvoid mousePressed() {\r\n  initNomads(mouseX, mouseY);\r\n} \r\n\r\n\/\/ A class for a little wanderer\r\nclass Nomad {\r\n  PVector velocity, pos, oldPos;\r\n  color clr;\r\n  float r, opacity;\r\n\r\n  Nomad(float startX, float startY, color startClr, float startR) {\r\n    pos = new PVector(startX, startY);\r\n    oldPos = pos.get();\r\n    clr = startClr;\r\n    r = startR;\r\n    opacity = random(.25, .5);\r\n    velocity = new PVector(random(.5, 1), random(.5, 1));\r\n    if (random(100)>50) velocity.x *= -1;\r\n    if (random(100)>50) velocity.y *= -1;\r\n  } \r\n\r\n  \/* Each Nomad has a velocity and a position. On each frame, the\r\n  position is updated by the velocity. The velocity changes on every\r\n  frame, inheriting some change from the underlying noise. *\/\r\n\r\n  void update() {\r\n    \/\/ Get a new value for the velocity from the noise\r\n    float vx = noise(pos.x*NoiseScale, pos.y*NoiseScale);\r\n    float vy = noise((2*width)+(pos.x*NoiseScale), (2*height)+(pos.y*NoiseScale));\r\n    \/\/ Noise values are from (0,1) but we want them from (-1,1)\r\n    vx = lerp(-1, 1, vx);\r\n    vy = lerp(-1, 1, vy);\r\n    \/\/ Get some \"blending factors\" to control how the velocity updates\r\n    float bx = lerp(.25, .75, noise(pos.y * NoiseScale));\r\n    float by = lerp(.25, .75, noise(pos.x * NoiseScale));\r\n    \/\/ Add some of the new values to the velocity\r\n    velocity.x += bx*vx;\r\n    velocity.y += by*vy;\r\n    \/\/ Normalize the velocity, save the old point, update the position\r\n    velocity.normalize();\r\n    oldPos = pos.get();\r\n    pos.x += velocity.x;\r\n    pos.y += velocity.y; \r\n    \/\/ Finally, make the particle just ever so slightly less opaque\r\n    opacity *= .995;\r\n  }\r\n\r\n  void render() {\r\n    stroke(clr, opacity*255);\r\n    strokeWeight(r);\r\n    noFill();\r\n    line(oldPos.x, oldPos.y, pos.x, pos.y);\r\n  }\r\n}<\/pre>\n","protected":false},"excerpt":{"rendered":"
My 2D graphics course went live today! It was hot here last night so I slept on the couch downstairs, and by coincidence my dog woke me up around 12:30. Since the course materials were supposed to appear on the site at midnight, I checked – and there they were! So everything seems smooth so […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-66","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/posts\/66","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/comments?post=66"}],"version-history":[{"count":26,"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/posts\/66\/revisions"}],"predecessor-version":[{"id":159,"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/posts\/66\/revisions\/159"}],"wp:attachment":[{"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/media?parent=66"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/categories?post=66"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.imaginary-institute.com\/blog\/wp-json\/wp\/v2\/tags?post=66"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}