Sorry, recording the screen cast did not work.
Instead find the source code of the FractalTree from the lecture here:
package de.uks.ep1415.m1234567.ha11; import processing.core.PApplet; public class FractalTree extends PApplet { @Override public void setup() { size(400, 600); } float totalSize = 5; @Override public void draw() { background(255); drawTree(200, 550, PI/2, totalSize); totalSize++; } private void drawTree(float rootX, float rootY, float angle, float size) { float topX = rootX + size * cos(angle); float topY = rootY - size * sin(angle); stroke(139,69,19); strokeWeight(size / 20); line(rootX, rootY, topX, topY); noStroke(); fill(0, 255, 0); ellipse(topX, topY, 10, 10); if (size >= 10) { drawTree((topX+rootX)/2, (topY+rootY)/2, angle-PI/4, size*0.7f); drawTree((topX+rootX)/2, (topY+rootY)/2, angle+PI/4, size*0.6f); } } }