…code, cg, electronics, 3d printing…

One of the main goals I have with using the Ostrich-Egg Bot is to generate art for it via Processing.  I’ve successfully drawn and etched a variety of random svg graphics onto a variety of surfaces.  Next step was to get that art from Processing.

Turned out to be a bit more difficult than I expected:  Processing has no native API call for exporting svg’s (that I can find).  But I finally grasped the fact that it can export pdf files via its pdf library.  And these, when imported into Inkscape, have the exact paths you need to plot.  Here’s a vid of the etcher in action based on a Processing-generated image:

And here’s the source for a simple Processing sketch that makes use of this:  The sketch draws a bunch of overlapping circles, larger on the bottom, smaller on the top, and makes sure there is no seam on the edge:

// eggbot_circles01

import processing.pdf.*;

int eggWidth = 3200;
int eggHeight = 800;
int minSize = 32;
int maxSize = 256;

void setup() {
  size(eggWidth, eggHeight);
  smooth();
  background(255);
  frame.setTitle("Eggbot: Circles01");
  noFill();
  beginRecord(PDF, "processingCircles.pdf");
}

void draw() {
  float[] pos = {
    random(width), random(minSize/2, height-maxSize/2)
  };
  float eSize = map(pos[1], minSize/2, height-maxSize/2, minSize, maxSize);
  ellipse(pos[0], pos[1], eSize, eSize);

  // Tile the circles on the x axis:
  if (pos[0] < eSize/2) {     
    ellipse(pos[0]+width, pos[1], eSize, eSize);   
  }   
  else if (pos[0] > width-eSize/2) {
    ellipse(pos[0]-width, pos[1], eSize, eSize);
  }
}

void keyPressed()
{
  if (key == 's') {
    endRecord();
    exit();
  }
}

When the sketch is going, press ‘s’ to save an image, and quit. It actually raises an exception, but the image saves… not sure what’s going on…

From there it’s a simple matter of importing the pdf into Inkscape. I discovered however that its size was bigger than what was defined in the sketch, so I had to resize it to fit the Ostrich-Egg Bot’s drawing area. Here is a close-up of the etcher in action:

And here’s a shot of the final product:

So, not the most amazing thing, but one step closer…