Wobbly Circles and the Center of Mass

What shape can roll well, other than a circle (wheel)? Two circles, attached together according to a formula involving a square root of two! Simon made these “wobbly circles” inspired by a Numberphile video where Matt Parker talks about how the ability to roll well (as in a wheel) is caused by the constant height of the center of mass (as opposed to a square wheel, whose center of mass goes zigzagging up and down). Wobbly wheels also have a stable height of their center of mass, hence they roll!

Simon also made a transparent version (with mom’s help):









Light and Texture in p5.js

Studying directional light and texture in p5.js produced some fun results, especially when the webcam was involved. Based on tutorials by Daniel Shiffman.


The Snowball Throwing Game in Processing

Simon invented this fun game in Processing after he and his little sister had some proper winter fun outdoors in the fresh December snow (quite rare for the local climate and thus immensely cherished by the little people). The game is about throwing  snowballs in such a trajectory that they stick to one another, forming a super-snowball. After I finished filming this, the two snowball throwers had such a great time with the game that I dare say the giggling effect from of this 2D simulation overshadowed the real snowball fight that had originally inspired it. They did love playing in the real snow on the next day though, until it melted away.


This slideshow requires JavaScript.

Playing with light and mirrors

This slideshow requires JavaScript.

Its Highness Magformers S.T.E.A.M. Master Set, Simon’s long aspired gift for Sinterklaas (the biggest holiday of the year for the Dutch) and what he built with it. The set mainly focuses on studying the way light is reflected by mirrors (such as in a camera or a periscope).


Simon and Neva had been singing the traditional Sinterklaas songs (with new non-racist and non-violent lyrics) every evening and finding small gifts in their shoes every morning for two weeks, this whole roller-coaster culminating in the Sinterklaas “pakjesavond” (the night of the presents) in early December with the extended family in Utrecht, where the “real gifts” were secretly delivered by Sint Nicolaas and his helpers. In the picture above, Simon is reading one of the poems (there are poems accompanying every gift). Sinterklaas was up all night last night writing poems.


At home unpacking the gift.

Simon writing a Matter.js textbook

Simon is currently working on a “Matter.js textbook”, a set of tutorials on how to use Matter.js (a physics library) that he writes on GitHub. Simon writes everything himself, not copying from anywhere. Sometimes he forgets some coding syntax and looks it up in the documentation, but for the rest this is his own text. He explains: “The reason why I am making this textbook is because there are Matter.js tutorials but they are really short and there aren’t many of them. And the only video tutorials are by Daniel Shiffman and they are using P5.js.” If it proves possible, Simon might add video to his GitHub textbook later.

It’s great to observe him type away and when I look over his shoulder, I see that he makes very decent sentences, with a nice tint of humour every now and then.

The link to the textbook:


Simon’s Particle Train

Simon made a particle system based on Daniel Shiffman’s latest live stream. Here is the link to Simon’s code on CodePen: https://codepen.io/simontiger/pen/OxvYYW?editors=0010

He also tweeted about it:

Simon Proposes a Community Project in Procedural Design

Inspired by the Processing Community Day projects, Simon came up with an idea to launch his own community project – in procedural design. He used the Coding Train Community Cloud page as inspiration, trying to guess the code used to build it. The videos below show Simon in process of creating the interface.

Simon later presented his project on the Coding Train Slack channel where other members (including Daniel Shiffman) suggested that Simon narrowed down the theme (originally, it was procedural design projects in general and that was too broad). Simon was very upset as he was afraid his “big project” would become too small and couldn’t come up with a theme. Two days later we agreed that he would make several examples for the projects and publish them on the project’s website to give everyone a better idea of what he was looking for.

At the moment, Simon has already published the first example but there seems to be a bug in it, so please view it as work in progress. (Simon originally wrote the code for the Community Cloud project and it worked when he shared it in Processing JS, but on his own project page, using instance mode, the cloud looks like a circle).

Simon writes: Everybody is welcome to contribute to my community project called *Procedural Designs*!
Link to GitHub rep (for this community project: https://github.com/simon-tiger/procedural-designs/ (link to github pages site in the README).