It seems that the certbot, the recommended script to install and update the LetsEncrypt certificates requires root permissions. Well, I found several tutorials and forums where people claimed that they ran it without root permissions but they all said they needed root permissions to do something else for certbot to work and then I ran this simple command:
$ ./certbot-auto --help
Requesting to rerun ./certbot-auto with root privileges...
[sudo] password for eleni:
and decided to give up and search for an alternative method. 🙂
FOSSCOMM (Free and Open Source Software Communities Meeting) is a Greek conference aiming at free-software and open-source enthusiasts, developers, and communities. The event is solely organized and ran by volunteers (usually university students, communities, Linux User Groups) and is taking place in a different city every year. The attendance is free and everyone is welcome to make a presentation or a workshop related to free and open source projects.
There are several methods to create and display a terrain, in real-time. In this post, I will explain the approach I followed on the demo I’m writing for my work at Igalia. Some work is still in progress.
The terrain had to meet the following requirements:
its size should be arbitrary
parts outside the viewer’s field of view should be culled
Sometimes, when working with the mesa drivers, modifying or replacing a shader might be extremely useful for debugging. Mesa allows users to replace their shaders at runtime without having to change the original code by providing these environment variables:
As part of my work for Igalia I wanted to do some environment mapping. I was able to find plenty of high quality .hdr images online but I couldn’t find any (OSS) tool to convert them to cubemap images. Then, Nuclear (John Tsiombikas) gave me the solution: he wrote a minimal tool that does the job quickly and produces high quality cube maps.
So, here’s a short “how to” create cubemaps on Linux using his “cubemapper” program in combination with other OSS tools:
Today, I experimented with the linux kernel modules for the first time and I’ve written a simple module that prints a message (helloworld :P) every time that someone reads from the /dev/ktest (a custom character device) and counts how many times the device was opened for reading.
So far, I hadn’t try to morph 3D objects to other 3D objects and I thought it’s something tricky to do. Today, I realized how simple and easy it is when I wrote this small test:
If you carefully choose the 3D models to have the same number of polygons, and to meet a few topological requirements, then you only need to interpolate the values of the meshes’ vectors, normals (and materials, textures, whatever you need) and draw the intermediate mesh every time. As interpolation parameter you can choose the values of a positive function that varies from 0 to 1 and backwards (I used (sin(msecs/factor) + 1)/2) to have that continuously changing effect. And that’s all! 😀