Guillaume Chereau, Software Engineer

The blue eyes island is a tricky logic puzzle that has several variations. The one I was first told was: A group of people live in an island with no contact with the outside world. Eyes color is big taboo for them and they strictly follow this rule: if anybody figures out the color of their own eyes, they will commit suicide the following night. Everybody knows the eyes color of all the other islanders, but nobody knows their own eyes color....

This post will be my attempt to explain intuitively what is Quantum Field Theory. This idea came to me after reading two books: “QED: The Strange Theory of Light and Matter” by Richard Feynman, and “Quantum Field Theory in a Nutshell”, by A. Zee (that I only started). Both books use path integrals, but in a very different way: Feynman tells us that the particles can move anywhere they want in space and time, while Zee uses conventional ‘forward in time only’ paths but of a ‘mattress’ and not just one particle....

As of 2019, C and C++ are the only programming languages that are supported by virtually any platforms on the market. For example both iOS and android support compiling C and C++ directly as part of their official IDEs. This is one of the reason why I decided to write my voxel editor Goxel in C99: I wanted to be able to run it on Linux, Mac, Windows, iOS, and now I am working on a Android port as well....

I recently started to see how to integrate a generic script language into my voxel editor Goxel. I want to use something light and easily embeddable into a C application. One obvious choice for this is to use Lua, but I also wanted to try Duktape, a lightweight JavaScript interpreter. In this post I’ll give some of my conclusions after trying both. 1. SIMPLICITY TO EMBED Both Lua and Duktape are relatively easy to embed into a C application....

Yesterday I tried to improve the style of my voxel editor goxel. One thing I wanted to do in particual is have better looking icons in the UI. The current icons looked like that on my non retina screen: This is what I came up with: It’s interesting to work on art for computer screen because for such small size images, the pixels aliasing quality becomes primordial. For example in goxel on a non retina screen, the icons should all have a size of 22x22 pixels....

I just made the first release of my voxel editor project goxel for iOS, and I wanted to write a bit about the process. It’s not the first time I work on a mobile port of C/C++ application, so the process was quite easy. The only new challenge this time is that I used swift on the platform code (instead of objective-C). The global structure of the code consists of a core written in C (or C++), and a small platform dependant layer on top of it to create the application context and handle the inputs....

I was wondering how to compute the rotations for all the faces of the regular dodecahedron (polyhedron with 12 faces). You can find many resources online about the symmetry group of the dodecahedron, but not much practical information about how you would use it in you code, this is specially annoying for non mathematicians like me who don’t want to go too far down the rabbit hole of group theory just to get my 12 rotations....

In this second part of my series about goxel voxel editor internals, I will talk about the way voxel data is stored in memory. As usual, all the code is open source and accessible on the github repo. The voxel models are composed of many individual voxel, each of them having a color. For the structure of the voxel I wanted: Optimized memory usage: if a model is large but composed of few voxels I don’t want to use extra memory for the empty spaces....

This is the first in a series of posts I want to write about the technical aspect of writing a voxel engine / editor. I wrote a free and open source voxel editor available on github, and I wanted to share the things I learned in the process. Today’s post is just an introduction, where I am going to talk about the evolution of computer graphics and the advent of voxels....

I just released Noctua Sky, a new project I am working on. This is an online planetarium (or sky map) software similar to the open source project Stellarium made by my brother. The goal of the project is ultimately to provide a set of tools and API for amateur astronomers to share their observations online. The first step toward this is to create a JavaScript planetarium that can run directly on the browser....