Différences

Ci-dessous, les différences entre deux révisions de la page.

--- recherche:residence_infra:start [2024/11/13 18:00]
gweltaz [Quaternion]
+++ recherche:residence_infra:start [2024/11/22 18:03] (Version actuelle)
exsitu [Infra-Documentation (ExSitu)]
@@ Ligne 1: / Ligne 1: @@
 ======INFRA======
+===== Infra-Documentation (ExSitu) =====
+Test de l'outil Multitude fraîchement développer par Laurent et permettant de collecter du son directement depuis une appli web, de l'archiver et de le rediffuser.
+Le résultat sur 4 jours de résidence : https://multitude.exsitu.xyz/v/visu/1931309934af589f4
+La version map GPS : https://multitude.exsitu.xyz/v/map/1931309934af589f4
+{{:recherche:residence_infra:inframultitude.png?nolink&400|}}
+Démonstration de la diffusion sur 7 enceintes :
+{{:recherche:residence_infra:infraenceintesx7.png?nolink&400|}}
+Gitlab : https://gitlab.com/losylam/multitude
 ===== Laurent =====
@@ Ligne 24: / Ligne 40: @@
-Profiter de ces beaux jours d'automne pour se chauffer au néons et ressortir la petite [[bobineuse https://ressources.labomedia.org/bobineuse?s[]=bobineuse]] pour créer un mirco
+Profiter de ces beaux jours d'automne pour se chauffer au néons et ressortir la petite [[https://ressources.labomedia.org/bobineuse?s|bobineuse]] pour créer un mirco
 ====la base infrastructurelle====
@@ Ligne 62: / Ligne 78: @@
 ===== Quaternion =====
+**Exploration des quaternions et de la modélisation procedurale avec Processing**
+Une vidéo qui m'a bien aidée à comprendre le ce truc : https://www.youtube.com/watch?v=bKd2lPjl92c
 {{:recherche:residence_infra:capture_d_ecran_du_2024-11-10_23-26-27.png?nolink&400|}}
@@ Ligne 70: / Ligne 90: @@
 {{:recherche:residence_infra:capture_d_ecran_du_2024-11-11_23-24-57.png?nolink&400|}}
+Les sketchs Processing ci-dessous dépendent de façon importante sur deux librairies non officielles:
+  * **QueasyCam** (modifié), pour la navigation dans l'espace en 3D -> https://github.com/gweltou/queasycam/tree/master/distribution/queasycam-6/download/
+  * **LibAvatar**, pour l'intégration des classes de LibGDX dans Processing -> https://github.com/gweltou/Processing-libAvatar/blob/2.0/distribution/libAvatar-3/download/libAvatar.zip
+Vous pouvez naviguer dans l'espace 3D avec les touches <key>z</key><key>q</key><key>s</key><key>d</key><key>a</key> et <key>e</key>. Affichage en mode filaire avec <key>w</key>.
+<accordion><panel title="iteration1.pde">
+<code java>
+import queasycam.*;
+import com.badlogic.gdx.math.*;
+import nervoussystem.obj.*;
+QueasyCam cam;
+static final Vector3 xAxis = new Vector3(1.0, 0.0, 0.0);
+float rootSize = 8;
+int numSeg = 128;
+Segment root = new Segment(null, 10, new Quaternion());
+public void setup() {
+  fullScreen(P3D);
+  cam = new QueasyCam(this, 1, 9999);
+  cam.key_forward = 'o';
+  cam.key_left = 'k';
+  cam.key_backward = 'l';
+  cam.key_right = 'm';
+  cam.key_up = 'i';
+  cam.key_down = 'p';
+  sphereDetail(16);
+  Segment c1 = root.branch(rootSize, new Quaternion().setEulerAngles(0, 0, -100));
+  Segment c2 = root.branch(rootSize, new Quaternion().setEulerAngles(120, 0, -100));
+  Segment c3 = root.branch(rootSize, new Quaternion().setEulerAngles(240, 0, -100));
+  for (int i=0; i<numSeg; i++) {
+    c1 = c1.branch(rootSize * pow(1.0-i/(20.0*numSeg), i), new Quaternion());
+    c2 = c2.branch(rootSize * pow(1.0-i/(20.0*numSeg), i), new Quaternion());
+    c3 = c3.branch(rootSize * pow(1.0-i/(20.0*numSeg), i), new Quaternion());
+  }
+  root.update();
+}
+public void draw() {
+  checkKeys();
+  background(255);
+  lights();
+  noStroke();
+  translate(width/2, height/2);
+  sphere(50);
+  root.draw();
+}
+void checkKeys() {
+  if (keyPressed == false)
+    return;
+  float step = 0.1;
+  Quaternion rotation = new Quaternion();
+  if (key == 'a') {
+    rotation.setEulerAngles(-step, 0.0, 0.0);
+  }
+  if (key == 'z') {
+    rotation.setEulerAngles(step, 0.0, 0.0);
+  }
+  if (key == 'q') {
+    rotation.setEulerAngles(0.0, -step, 0.0);
+  }
+  if (key == 's') {
+    rotation.setEulerAngles(0.0, step, 0.0);
+  }
+  if (key == 'w') {
+    rotation.setEulerAngles(0.0, 0.0, -step);
+  }
+  if (key == 'x') {
+    rotation.setEulerAngles(0.0, 0.0, step);
+  }
+  for (Segment seg : root.children) {
+    while (seg.hasChildren()) {
+      seg.localRot.mul(rotation).nor();
+      seg = seg.children.get(0);
+    }
+    seg.localRot.mul(rotation).nor();
+  }
+  root.update();
+}
+/*****************************
+**       class Segment      **
+*****************************/
+public class Segment {
+  static final int faces = 32;
+  static final float l2b = 10.0;  // Length to base ratio
+  protected Segment parent = null;
+  protected Vector3 head = new Vector3();
+  protected Vector3 rootWorldPos = null;
+  private Quaternion localRot = new Quaternion(); // Rotation from parent Segment
+  private Quaternion globalRot = new Quaternion(); // Total rotation in world space
+  private float len;
+  private float baseRadius;
+  private Vector3[] points = new Vector3[faces];
+  private Vector3 tmpVec = new Vector3();
+  private ArrayList<Segment> children = new ArrayList();
+  public Segment(Segment parent, float len, Quaternion rot) {
+    this.parent = parent;
+    if (parent == null) {
+      rootWorldPos = new Vector3();
+      globalRot = rot.cpy();
+    } else {
+      rootWorldPos = parent.rootWorldPos;
+    }
+    this.localRot = rot.cpy();
+    this.len = len;
+    baseRadius = len * l2b * 0.5;
+  }
+  public Segment branch(float len, Quaternion rot) {
+    Segment child = new Segment(this, len, rot);
+    children.add(child);
+    return child;
+  }
+  public boolean hasChildren() {
+    return !children.isEmpty();
+  }
+  public void draw() {
+    // Draw head line
+    stroke(0);
+    Vector3 up = new Vector3(0, len*0.4, 0);
+    globalRot.transform(up);
+    if (parent != null)
+      line(parent.head.x, parent.head.y, parent.head.z, head.x, head.y, head.z);
+    else
+      line(0.0, 0.0, 0.0, head.x, head.y, head.z);
+    // Draw UP line
+    stroke(255, 0, 0);
+    line(head.x, head.y, head.z, head.x + up.x, head.y + up.y, head.z + up.z);
+    noStroke();
+    if (hasChildren())
+      drawSegment();
+    else
+      drawTip();
+    for (Segment child : children)
+      child.draw();
+  }
+  private void drawSegment() {
+    beginShape(QUAD_STRIP);
+    for (int i=0; i<faces+1; i++) {
+      if (parent == null) {
+        Quaternion rot = new Quaternion();
+        rot.setFromAxisRad(xAxis, i * TWO_PI / faces);
+        rot.mulLeft(globalRot);
+        rot.transform(tmpVec);
+        tmpVec.set(len, baseRadius, 0.0);
+      } else {
+        tmpVec.set(parent.points[i%faces]);
+      }
+      vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+      tmpVec.set(points[i%faces]);
+      vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+    }
+    endShape();
+  }
+  private void drawTip() {
+    // Draw a capped tip if this segment has no children
+    beginShape(TRIANGLE_FAN);
+    vertex(head.x, head.y, head.z);
+    for (int i=0; i<faces+1; i++) {
+      if (parent == null) {
+        Quaternion rot = new Quaternion();
+        rot.setFromAxisRad(xAxis, i * TWO_PI / faces);
+        rot.mulLeft(globalRot);
+        rot.transform(tmpVec);
+        tmpVec.set(len, baseRadius, 0.0);
+      } else {
+        tmpVec.set(parent.points[i%faces]);
+      }
+    }
+    endShape();
+  }
+  public void update() {
+    Vector3 pos = rootWorldPos.cpy();
+    globalRot.set(localRot);
+    if (parent != null) {
+      pos.add(parent.head);
+      globalRot.mulLeft(parent.globalRot).nor();
+    }
+    head.set(len, 0.0, 0.0); // Going right by default
+    globalRot.transform(head);
+    head.add(pos);
+    float angle = 0.0;
+    Quaternion rot = new Quaternion();
+    for (int i=0; i<faces; i++) {
+      rot.setFromAxisRad(xAxis, angle);
+      rot.mulLeft(globalRot);
+      tmpVec.set(len, baseRadius, 0.0);
+      rot.transform(tmpVec);
+      points[i] = tmpVec.cpy().add(pos);
+      angle += TWO_PI / faces;
+    }
+    for (Segment child : children)
+      child.update();
+  }
+}
+</code>
+</panel></accordion>
+<accordion><panel title="iteration2.pde">
+<code java>
+import queasycam.*;
+import com.badlogic.gdx.math.*;
+import nervoussystem.obj.*;
+import processing.pdf.*;
+static final Vector3 xAxis = new Vector3(1.0, 0.0, 0.0);
+static final Vector3 yAxis = new Vector3(0.0, 1.0, 0.0);
+static final Vector3 zAxis = new Vector3(0.0, 0.0, 1.0);
+QueasyCam cam;
+boolean wireframe = false;
+boolean record = false;
+ArrayList<Drawable> objects = new ArrayList();
+public void setup() {
+  fullScreen(P3D);
+  //size(800, 600, P3D);
+  cam = new QueasyCam(this, 1, 9999);
+  cam.key_forward = 'z';
+  cam.key_left = 'q';
+  cam.key_backward = 's';
+  cam.key_right = 'd';
+  cam.key_up = 'e';
+  cam.key_down = 'a';
+  Pipe pipe = new Pipe(
+    new Vector3(0, 0, 0), new Quaternion().setEulerAngles(10, 0, 40),
+, 32);
+  objects.add(pipe);
+  float size = 20;
+  for (int i=0; i<8; i++) {
+    pipe.changeSize(size);
+    size += 10;
+    pipe.addBend(90, 0.0, 45.0);
+  }
+}
+public void draw() {
+  background(255);
+  lights();
+  strokeWeight(1);
+  stroke(255, 0, 0);
+  line(0, 0, 0, 100, 0, 0);
+  stroke(0, 255, 0);
+  line(0, 0, 0, 0, 100, 0);
+  stroke(0, 0, 255);
+  line(0, 0, 0, 0, 0, 100);
+  if (wireframe)
+    stroke(0);
+  else
+    noStroke();
+  strokeWeight(2);
+  if (record) {
+    beginRaw(PDF, "output.pdf");
+    noFill();
+  }
+  for (Drawable o : objects)
+    o.draw();
+  if (record) {
+    record = false;
+    endRaw();
+  }
+}
+void keyPressed() {
+  if (key == 'w')
+    wireframe = !wireframe;
+  if (key == 'p')
+    record = true;
+}
+public interface Drawable {
+  public void draw();
+  public void update();
+}
+public interface Chainable extends Drawable {
+  public Vector3 getOutPos();
+  public Quaternion getOutOrientation();
+}
+/*****************************
+**        class Pipe        **
+*****************************/
+public class Pipe implements Drawable {
+  private Vector3 pos;
+  private Quaternion orientation;
+  private float radius;
+  private float nextRadius;
+  private int faces;
+  private ArrayList<Chainable> objects = new ArrayList();
+  private Vector3 currentPos;
+  private Quaternion currentOrientation;
+  public Pipe(Vector3 pos, Quaternion orientation, float radius, int faces) {
+    this.pos = pos;
+    this.orientation = orientation;
+    this.radius = radius;
+    this.nextRadius = radius;
+    this.faces = faces;
+    currentPos = this.pos.cpy();
+    currentOrientation = orientation.cpy();
+  }
+  public void changeSize(float next) {
+    this.nextRadius = next;
+  }
+  private void add(Chainable object) {
+    objects.add(object);
+    currentPos = object.getOutPos();
+    currentOrientation = object.getOutOrientation();
+    radius = nextRadius;
+  }
+  public void addTube(float len) {
+    addTube(len, 0.0);
+  }
+  public void addTube(float len, float twist) {
+    Tube tube = new Tube(
+      currentPos, currentOrientation,
+      len, radius, nextRadius, twist, 1, faces
+      );
+    add(tube);
+  }
+  public void addBend(float angleBendDeg) {
+    addBend(angleBendDeg, 0.0, 0.0);
+  }
+  public void addBend(float angleBendDeg, float angleRotDeg) {
+    addBend(angleBendDeg, angleRotDeg, 0.0);
+  }
+  public void addBend(float angleBendDeg, float angleRotDeg, float twist) {
+    int rings = 8;
+    float radInt = 50;
+    currentOrientation.mul(new Quaternion().setEulerAngles(0, angleRotDeg, 0));
+    Bend bend = new Bend(
+      currentPos, currentOrientation,
+      radius, nextRadius,
+      radians(angleBendDeg), radInt, twist,
+      rings, faces
+      );
+    add(bend);
+  }
+  public void update() {
+    for (Chainable o : objects)
+      o.update();
+  }
+  public void draw() {
+    for (Chainable o : objects) {
+      o.draw();
+    }
+    Vector3 head = currentOrientation.transform(new Vector3(32, 0, 0));
+    head.add(currentPos);
+    line(currentPos.x, currentPos.y, currentPos.z, head.x, head.y, head.z);
+  }
+}
+/*****************************
+**        class Tube        **
+*****************************/
+public class Tube implements Drawable, Chainable {
+  private Vector3 pos;
+  private Quaternion orientation;
+  private float len;
+  private float radiusIn;
+  private float radiusOut;
+  private float twist;
+  private int rings;
+  private int faces;
+  private Vector3[] points;
+  private Vector3 tmpVec = new Vector3();
+  private Vector3 outPos = new Vector3();
+  private Quaternion outOrientation = new Quaternion();
+  public Tube(
+    Vector3 pos,
+    Quaternion orientation,
+    float len,
+    float radiusIn,
+    float radiusOut,
+    float twist,  // In degrees
+    int rings, int faces
+    ) {
+    this.pos = pos.cpy();
+    this.orientation = orientation.cpy();
+    this.len = len;
+    this.radiusIn = radiusIn;
+    this.radiusOut = radiusOut;
+    this.twist = radians(twist);
+    this.rings = rings;
+    this.faces = faces;
+    points = new Vector3[faces * (rings+1)];
+    update();
+  }
+  Vector3 getOutPos() {
+    return outPos.cpy();
+  }
+  Quaternion getOutOrientation() {
+    return outOrientation.cpy();
+  }
+  public void update() {
+    Quaternion rot = new Quaternion();
+    int pointIdx = 0;
+    for (int s=0; s<rings+1; s++) {
+      float angle = s * twist/rings;
+      for (int i=0; i<faces; i++) {
+        tmpVec.set(s * len/rings, map(s, 0, rings, radiusIn, radiusOut), 0.0);
+        rot.setFromAxisRad(xAxis, angle).mulLeft(orientation);
+        rot.transform(tmpVec);
+        points[pointIdx++] = tmpVec.cpy().add(pos);
+        angle += TWO_PI / faces;
+      }
+    }
+    outOrientation.set(orientation);
+    outOrientation.mul(new Quaternion().setFromAxisRad(xAxis, twist));
+    outPos.set(len, 0.0, 0.0);
+    outOrientation.transform(outPos);
+    outPos.add(pos);
+  }
+  public void draw() {
+    for (int s=0; s<rings; s++) {
+      beginShape(QUAD_STRIP);
+      for (int i=0; i<faces+1; i++) {
+        tmpVec.set(points[s * faces + i%faces]);
+        vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+        tmpVec.set(points[(s+1) * faces + i%faces]);
+        vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+      }
+      endShape();
+    }
+  }
+}
+/*****************************
+**        class Bend        **
+*****************************/
+public class Bend implements Drawable, Chainable {
+  private Vector3 pos;
+  private Quaternion orientation;
+  private float radiusIn;
+  private float radiusOut;
+  private float bendAngle;
+  private float radInt;
+  private float twist;
+  private int rings;
+  private int faces;
+  private Vector3[] points;
+  private Vector3 tmpVec = new Vector3();
+  private Vector3 outPos = new Vector3();
+  private Quaternion outOrientation = new Quaternion();
+  public Bend(
+      Vector3 pos,
+      Quaternion orientation,
+      float radiusIn,
+      float radiusOut,
+      float bendAngle, // In radians
+      float radInt, // Internal radius
+      float twist,
+      int rings,
+      int faces
+    ) {
+    this.pos = pos.cpy();
+    this.orientation = orientation.cpy();
+    this.radiusIn = radiusIn;
+    this.radiusOut = radiusOut;
+    this.bendAngle = bendAngle;
+    this.radInt = radInt;
+    this.twist = radians(twist);
+    this.rings = rings;
+    this.faces = faces;
+    points = new Vector3[faces * (rings+1)];
+    update();
+  }
+  Vector3 getOutPos() {
+    return outPos.cpy();
+  }
+  Quaternion getOutOrientation() {
+    return outOrientation.cpy();
+  }
+  public void update() {
+    int pointIdx = 0;
+    Quaternion segRot = new Quaternion();
+    Quaternion rot = new Quaternion();
+    Vector3 bendOffset = new Vector3(0.0, radInt + radiusIn, 0.0);
+    orientation.transform(bendOffset);
+    float angleSeg = 0.0;
+    for (int s=0; s<rings+1; s++) {
+      segRot.setFromAxisRad(zAxis, angleSeg);
+      segRot.mulLeft(orientation);
+      float tubeRadius = map(s, 0, rings, radiusIn, radiusOut);
+      Vector3 segOffset = new Vector3(0.0, radInt + tubeRadius, 0.0);
+      segRot.transform(segOffset);
+      angleSeg += bendAngle / rings;
+      float angle = s * twist/rings;
+      for (int i=0; i<faces; i++) {
+        tmpVec.set(0.0, tubeRadius, 0.0);
+        rot.setFromAxisRad(xAxis, angle);
+        rot.mulLeft(segRot);
+        rot.transform(tmpVec);
+        points[pointIdx++] = tmpVec.cpy().sub(segOffset).add(bendOffset).add(pos);
+        angle += TWO_PI / faces;
+      }
+    }
+    outPos.set(0, -radiusOut - radInt, 0);
+    outOrientation.set(orientation);
+    outOrientation.mul(new Quaternion().setFromAxisRad(zAxis, bendAngle));
+    outOrientation.transform(outPos);
+    outOrientation.mul(new Quaternion().setFromAxisRad(xAxis, twist));
+    tmpVec.set(0.0, radInt + radiusIn, 0.0);
+    orientation.transform(tmpVec);
+    outPos.add(tmpVec).add(pos);
+  }
+  public void draw() {
+    for (Vector3 p : points) {
+      point(p.x, p.y, p.z);
+    }
+    for (int s=0; s<rings; s++) {
+      beginShape(QUAD_STRIP);
+      for (int i=0; i<faces+1; i++) {
+        tmpVec.set(points[s * faces + i%faces]);
+        vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+        tmpVec.set(points[(s+1) * faces + i%faces]);
+        vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+      }
+      endShape();
+    }
+  }
+}
+</code>
+</panel></accordion>
+<accordion><panel title="scene.pde">
+<code java>
+import queasycam.*;
+import com.badlogic.gdx.math.*;
+static final Vector3 xAxis = new Vector3(1.0, 0.0, 0.0);
+static final Vector3 yAxis = new Vector3(0.0, 1.0, 0.0);
+static final Vector3 zAxis = new Vector3(0.0, 0.0, 1.0);
+QueasyCam cam;
+boolean wireframe = false;
+ArrayList<Drawable> objects = new ArrayList();
+public void setup() {
+  fullScreen(P3D);
+  cam = new QueasyCam(this, PConstants.PI/2.5f, 0.01, 9999);
+  cam.key_forward = 'z';
+  cam.key_left = 'q';
+  cam.key_backward = 's';
+  cam.key_right = 'd';
+  cam.key_up = 'e';
+  cam.key_down = 'a';
+  // Center tower
+  Pipe pipe = new Pipe(
+    new Vector3(0.0, 800, 0.0),
+    new Quaternion().setFromAxis(zAxis, -90),
+, 64);
+  pipe.addTube(1000);
+  pipe.changeSize(800);
+  pipe.addTube(1000);
+  pipe.changeSize(820);
+  pipe.addTube(20);
+  pipe.changeSize(2600);
+  pipe.addTube(200);
+  pipe.addTube(-400);
+  objects.add(pipe);
+  // Surrounding circus
+  pipe = new Pipe(
+    new Vector3(0.0, 800, 0.0),
+    new Quaternion().setFromAxis(zAxis, -90),
+, 64);
+  pipe.addTube(600);
+  pipe.changeSize(2000);
+  pipe.addTube(200);
+  pipe.changeSize(2040);
+  pipe.addTube(40);
+  pipe.addTube(1000);
+  objects.add(pipe);
+  for (int r=0; r<4; r++) {
+    Quaternion rot = new Quaternion().setEulerAngles(r * 90, 0, 9);
+    for (int i=0; i<6; i++) {
+      Vector3 pos = new Vector3(-2100, 298, (i-3)*34 + 17);
+      rot.transform(pos);
+      pipe = new Pipe(pos, rot, 16, 16);
+      pipe.addTube(1480 + 4 * abs(i-3));
+      pipe.addBend(99, 180);
+      pipe.addTube(300, (3-i) * 5);
+      pipe.addBend(14);
+      if (abs(i-2.5)<=1) {
+        pipe.addTube(860);
+        pipe.changeSize(24);
+        pipe.addTube(18);
+        pipe.changeSize(26);
+        pipe.addTube(200);
+      } else {
+        pipe.addTube(1000);
+        pipe.addBend(70);
+        float l=0.0, ll=0.0;
+        int state = 0; // -1: left; 0: center; 1: right
+        while (l<1800) {
+          int turn = floor(random(3.0)-1.0);
+          if (state==0 && turn == -1) {
+            pipe.addBend(45, 90);
+            state = -1;
+          } else if (state==0 && turn == 1) {
+            pipe.addBend(45, -90);
+            state = 1;
+          } else if (state == -1 && turn == 1) {
+            pipe.addBend(45, 180, -90);
+            state = 0;
+          } else if (state == 1 && turn == -1) {
+            pipe.addBend(45, -180, 90);
+            state = 0;
+          } else if (state == 0) {
+            pipe.addTube(ll);
+            l += ll;
+            ll = 0.0;
+          }
+          ll += 100;
+        }
+      }
+     objects.add(pipe);
+    }
+    float deg = r * 90 + 45;
+    rot.setFromAxis(zAxis, -90);
+    rot.mul(new Quaternion().setFromAxis(xAxis, deg));
+    Vector3 pos = new Vector3(590 * cos(radians(deg)), 800, 590 * sin(radians(deg)));
+    pipe = new Pipe(pos, rot, 34, 16);
+    pipe.addTube(980);
+    pipe.addBend(14);
+    pipe.addTube(950);
+    pipe.addBend(70);
+    pipe.addTube(1800);
+    objects.add(pipe);
+    deg = r * 90 + 45;
+    rot.setFromAxis(zAxis, -90);
+    rot.mul(new Quaternion().setFromAxis(xAxis, deg));
+    pos = new Vector3(1700 * cos(radians(deg)), 50, 1700 * sin(radians(deg)));
+    pipe = new Pipe(pos, rot, 140, 32);
+    pipe.addBend(90, 0, 0, 300);
+    objects.add(pipe);
+  }
+}
+public void draw() {
+  background(0);
+  //lights();
+  //ambientLight(12, 4, 1);
+  //pointLight(100, 100, 110, 140, -2000, 144);
+  directionalLight(204, 204, 204, .5, 0.6, 0.2);
+  emissive(50, 46, 51);
+  //specular(204, 102, 0);
+  shininess(1.0);
+  strokeWeight(1);
+  stroke(255, 0, 0);
+  line(0, 0, 0, 100, 0, 0);
+  stroke(0, 255, 0);
+  line(0, 0, 0, 0, 100, 0);
+  stroke(0, 0, 255);
+  line(0, 0, 0, 0, 0, 100);
+  if (wireframe)
+    stroke(0);
+  else
+    noStroke();
+  strokeWeight(1);
+  for (Drawable o : objects)
+    o.draw();
+}
+void keyPressed() {
+  if (key == 'w')
+    wireframe = !wireframe;
+}
+public interface Drawable {
+  public void draw();
+  public void update();
+}
+public interface Chainable extends Drawable {
+  public Vector3 getOutPos();
+  public Quaternion getOutOrientation();
+}
+/*****************************
+**        class Pipe        **
+*****************************/
+public class Pipe implements Drawable {
+  private Vector3 pos;
+  private Quaternion orientation;
+  private float radius;
+  private float nextRadius;
+  private int faces;
+  private ArrayList<Chainable> objects = new ArrayList();
+  private Vector3 currentPos;
+  private Quaternion currentOrientation;
+  public Pipe(Vector3 pos, Quaternion orientation, float radius, int faces) {
+    this.pos = pos;
+    this.orientation = orientation;
+    this.radius = radius;
+    this.nextRadius = radius;
+    this.faces = faces;
+    currentPos = this.pos.cpy();
+    currentOrientation = orientation.cpy();
+  }
+  public void changeSize(float next) {
+    this.nextRadius = next;
+  }
+  private void add(Chainable object) {
+    objects.add(object);
+    currentPos = object.getOutPos();
+    currentOrientation = object.getOutOrientation();
+    radius = nextRadius;
+  }
+  public void addTube(float len) {
+    addTube(len, 0.0);
+  }
+  public void addTube(float len, float twist) {
+    Tube tube = new Tube(
+      currentPos, currentOrientation,
+      len, radius, nextRadius, twist, 1, faces
+      );
+    add(tube);
+  }
+  public void addBend(float angleBendDeg) {
+    addBend(angleBendDeg, 0.0, 0.0);
+  }
+  public void addBend(float angleBendDeg, float angleRotDeg) {
+    addBend(angleBendDeg, angleRotDeg, 0.0);
+  }
+  public void addBend(float angleBendDeg, float angleRotDeg, float twist) {
+    float radInt = 50;
+    addBend(angleBendDeg, angleRotDeg, twist, radInt);
+  }
+  public void addBend(float angleBendDeg, float angleRotDeg, float twist, float radInt) {
+    int rings = ceil(angleBendDeg * 64.0 / 360.0);
+    currentOrientation.mul(new Quaternion().setEulerAngles(0, angleRotDeg, 0));
+    Bend bend = new Bend(
+      currentPos, currentOrientation,
+      radius, nextRadius,
+      radians(angleBendDeg), radInt, twist,
+      rings, faces
+      );
+    add(bend);
+  }
+  public void update() {
+    for (Chainable o : objects)
+      o.update();
+  }
+  public void draw() {
+    for (Chainable o : objects) {
+      o.draw();
+    }
+    Vector3 head = currentOrientation.transform(new Vector3(32, 0, 0));
+    head.add(currentPos);
+    line(currentPos.x, currentPos.y, currentPos.z, head.x, head.y, head.z);
+  }
+}
+/*****************************
+**        class Tube        **
+*****************************/
+public class Tube implements Drawable, Chainable {
+  private Vector3 pos;
+  private Quaternion orientation;
+  private float len;
+  private float radiusIn;
+  private float radiusOut;
+  private float twist;
+  private int rings;
+  private int faces;
+  private Vector3[] points;
+  private Vector3 tmpVec = new Vector3();
+  private Vector3 outPos = new Vector3();
+  private Quaternion outOrientation = new Quaternion();
+  public Tube(
+    Vector3 pos,
+    Quaternion orientation,
+    float len,
+    float radiusIn,
+    float radiusOut,
+    float twist,  // In degrees
+    int rings, int faces
+    ) {
+    this.pos = pos.cpy();
+    this.orientation = orientation.cpy();
+    this.len = len;
+    this.radiusIn = radiusIn;
+    this.radiusOut = radiusOut;
+    this.twist = radians(twist);
+    this.rings = rings;
+    this.faces = faces;
+    points = new Vector3[faces * (rings+1)];
+    update();
+  }
+  Vector3 getOutPos() {
+    return outPos.cpy();
+  }
+  Quaternion getOutOrientation() {
+    return outOrientation.cpy();
+  }
+  public void update() {
+    Quaternion rot = new Quaternion();
+    int pointIdx = 0;
+    for (int s=0; s<rings+1; s++) {
+      float angle = s * twist/rings;
+      for (int i=0; i<faces; i++) {
+        tmpVec.set(s * len/rings, map(s, 0, rings, radiusIn, radiusOut), 0.0);
+        rot.setFromAxisRad(xAxis, angle).mulLeft(orientation);
+        rot.transform(tmpVec);
+        points[pointIdx++] = tmpVec.cpy().add(pos);
+        angle += TWO_PI / faces;
+      }
+    }
+    outOrientation.set(orientation);
+    outOrientation.mul(new Quaternion().setFromAxisRad(xAxis, twist));
+    outPos.set(len, 0.0, 0.0);
+    outOrientation.transform(outPos);
+    outPos.add(pos);
+  }
+  public void draw() {
+    for (int s=0; s<rings; s++) {
+      beginShape(QUAD_STRIP);
+      for (int i=0; i<faces+1; i++) {
+        tmpVec.set(points[s * faces + i%faces]);
+        vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+        tmpVec.set(points[(s+1) * faces + i%faces]);
+        vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+      }
+      endShape();
+    }
+  }
+}
+/*****************************
+**        class Bend        **
+*****************************/
+public class Bend implements Drawable, Chainable {
+  private Vector3 pos;
+  private Quaternion orientation;
+  private float radiusIn;
+  private float radiusOut;
+  private float bendAngle;
+  private float radInt;
+  private float twist;
+  private int rings;
+  private int faces;
+  private Vector3[] points;
+  private Vector3 tmpVec = new Vector3();
+  private Vector3 outPos = new Vector3();
+  private Quaternion outOrientation = new Quaternion();
+  public Bend(
+      Vector3 pos,
+      Quaternion orientation,
+      float radiusIn,
+      float radiusOut,
+      float bendAngle, // In radians
+      float radInt, // Internal radius
+      float twist,
+      int rings,
+      int faces
+    ) {
+    this.pos = pos.cpy();
+    this.orientation = orientation.cpy();
+    this.radiusIn = radiusIn;
+    this.radiusOut = radiusOut;
+    this.bendAngle = bendAngle;
+    this.radInt = radInt;
+    this.twist = radians(twist);
+    this.rings = rings;
+    this.faces = faces;
+    points = new Vector3[faces * (rings+1)];
+    update();
+  }
+  Vector3 getOutPos() {
+    return outPos.cpy();
+  }
+  Quaternion getOutOrientation() {
+    return outOrientation.cpy();
+  }
+  public void update() {
+    int pointIdx = 0;
+    Quaternion segRot = new Quaternion();
+    Quaternion rot = new Quaternion();
+    Vector3 bendOffset = new Vector3(0.0, radInt + radiusIn, 0.0);
+    orientation.transform(bendOffset);
+    float angleSeg = 0.0;
+    for (int s=0; s<rings+1; s++) {
+      segRot.setFromAxisRad(zAxis, angleSeg);
+      segRot.mulLeft(orientation);
+      float tubeRadius = map(s, 0, rings, radiusIn, radiusOut);
+      Vector3 segOffset = new Vector3(0.0, radInt + tubeRadius, 0.0);
+      segRot.transform(segOffset);
+      angleSeg += bendAngle / rings;
+      float angle = s * twist/rings;
+      for (int i=0; i<faces; i++) {
+        tmpVec.set(0.0, tubeRadius, 0.0);
+        rot.setFromAxisRad(xAxis, angle);
+        rot.mulLeft(segRot);
+        rot.transform(tmpVec);
+        points[pointIdx++] = tmpVec.cpy().sub(segOffset).add(bendOffset).add(pos);
+        angle += TWO_PI / faces;
+      }
+    }
+    outPos.set(0, -radiusOut - radInt, 0);
+    outOrientation.set(orientation);
+    outOrientation.mul(new Quaternion().setFromAxisRad(zAxis, bendAngle));
+    outOrientation.transform(outPos);
+    outOrientation.mul(new Quaternion().setFromAxisRad(xAxis, twist));
+    tmpVec.set(0.0, radInt + radiusIn, 0.0);
+    orientation.transform(tmpVec);
+    outPos.add(tmpVec).add(pos);
+  }
+  public void draw() {
+    for (Vector3 p : points) {
+      point(p.x, p.y, p.z);
+    }
+    for (int s=0; s<rings; s++) {
+      beginShape(QUAD_STRIP);
+      for (int i=0; i<faces+1; i++) {
+        tmpVec.set(points[s * faces + i%faces]);
+        vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+        tmpVec.set(points[(s+1) * faces + i%faces]);
+        vertex(tmpVec.x, tmpVec.y, tmpVec.z);
+      }
+      endShape();
+    }
+  }
+}
+</code>
+</panel></accordion>