Wednesday, October 30, 2013

Inkscape magic and hard work

For a volleyball club Ascavoc in Belgium I was asked to make a t-shirt for their supporters. This had to include their own logo, but unfortunately we only had the following jpeg image at our disposal.

Which is ok if you are using it as a small icon on a website, but when you want it printed on a t-shirt it's looks like you need new glasses. So I want to explain a few steps I used to create a newer version which still looks like the old logo but is scalable. I use Inkscape a lot and for this problem I used a very useful feature called 'Trace Bitmap'. When you apply this without changing the settings you get a vectorized image as shown below.


Wait, what?! That looks terrible. Ok we have perfect black shapes that we can modify, scale, change color but it doesn't look like the old image. In the original image we could recognize straight lines or perfect circles, but in the process of vectorizing the image it failed miserably. In cases like you this you have do a lot of work to fix what the tracing can't do. This takes patience and practice. Sometimes removing a couple of point that define a line can already help a lot, but in this case I had to redraw certain parts of the image from scratch. For example replacing the head of the volleyball player with a circle. But in the end the result was satisfactory as you can see below

If you're really picky (like me) you'll notice small differences between the original drawing and this new version, but you've got to admit that for a lot of purposes vectorizing is so much nicer.

Tuesday, October 29, 2013

LEGO got so much cooler

One of the perks of my job is testing new equipment. The latest addition to our very important educational tools is the new LEGO EV3. (check out the trailer). If you've never heard of the LEGO robotics just a quick update. In 1998 first brought a programmable 'brick' on the market. This meant you could make you're own robot out of LEGO parts, add sensors and motors, and finally write a program to tell the robot how to behave.The EV3 is the third in the LEGO Mindstorms series and has some really nice features. Let's start with the sensor. The education kit that we have comes with two touch sensors, an ultrasonic distance meter, an accelerometer, a small engine that can tell you the angle it has turned and a light sensors that can also detect different colors. You can also get an infrared sensor and a remote control. And of course we can't do without the two large motors to get things moving about.
So I wanted to see if everything works, if it's understandable and if students could work with it. The first model that is described in the software looked really nice so I followed the building instructions, downloading the program and in the video below is the result. It's called Gyro Boy and it's a robot that can balance itself on two wheels. Pretty impressive.

Like I said this was just following instructions and that doesn't get you in a lot of problems. I was quite impressed with how nice the robot was designed. I haven't had the time yet to look into the program that stops it from falling over, but I'm guessing it will have some nice surprises too.
The real goal of course is getting students to work with the EV3, but I can already think of some problems interesting enough for a wide range of students. Hopefully I can update this subject some more in the near future.

Saturday, October 26, 2013

White Dwarfs in Three Dimensions

A short while ago my good friend Silvia Toonen finished her PhD in Astrophysics. The title of her thesis is "The Evolution of Close Binaries with White Dwarf Components". She honored me with two things: to be one of her paranimfs during her defense and also to design the cover of her thesis. After trying a number of things I finally convinced her a anaglyph cover would be totally awesome. Anaglyph, for those who are not familiar with the name, are the 3D images where you use red&blue glasses.  

With some internet research and some playing around with programs like Inkscape I discovered it wasn't that hard create a nice 3D effect with little effort. In the end getting something that I was really content with proved a lot of work, but it was worth it.

Some explanation is needed on what you're looking at. First of all her research topic is double star systems, so called binaries where at least one of the star is a white dwarf. A white dwarfs, as you all know, is a star at the end of it's career (wiki), and they are thought to play an important role in supernovae.
Back to the cover. The 3D part behind the title represents a double star system. In Silvia's last name the o's are replaced by a Roche Lobe. When two stars have close orbits they start to share matter which is called a Roche Lobe, and this is a schematic representation of that. To create this final image I had to use Matlab to draw the two orbiting sphere and orbits seen from two different angles. To turn the two images into an anaglyph image I settled for a program I found an online solution called StereoPhoto Maker. Finally putting it all together in Inkscape et voila!

Monday, October 14, 2013

Led Cubes are fun

If you haven't seen a LED cube yet, you're sure missing out. Well... let's just say they're pretty cool. It just wanted to share the end result of the LED cube I made myself. I thought it would be a nice chance to try out the Arduino microprocessor we have at the school I'm working at, to polish up my soldering skills and in the end create a nice demonstration model for students to marvel about or hopefully to work with in the future.

picture of my own LED cube
I'm not going to write a whole DIY instruction, the web is filled with that already. I found the animation that is running on the cube in the movie below on such a site. In the future I intend to make some other Arduino based projects. The end result makes it look pretty difficult, but believe me, if you take it step by step it's really doable.

Wednesday, October 9, 2013

Post Number 1

As a first post I would just like to say welcome to people reading this and say something shortly about what I am intending to post on this blog.

1) Welcome :)
2) What I want to write about on this is basically things I am or have been working on. This could be a data visualization, something I designed or anything I think is interesting to share. If I think it can be useful I intend to give a small explanation how I created the final product.

I hope you find things that inspire you to create things yourself.