blog.Habrador.com

The one who's running this blog is me, Erik Nordeus. I'm an imagineer (creative engineer) who's interested in the intersection between art and engineering.
This is my portfolio: Habrador.com

Explaining the Hybrid A Star pathfinding algorithm for selfdriving cars

Let's say you are standing somewhere in a room and would like to find the shortest path to a goal. You can see a few obstacles, such as a table, that you would like to avoid. The easiest way to solve the problem (if you are a computer) is to divide the room into many small squares (cells) and then use the common A* (A Star) search algorithm to find the shortest path. But what if you are a car and can't turn around 360 degrees like a human can, then you have a problem! Well, at least until you learn the Hybrid A Star search algorithm . With that algorithm you will be able to find a drivable path to the goal. The reason I wanted to learn the Hybrid A* algorithm was that I took a class in self-driving cars, where the teacher showed a really cool video with a car that drove around in a maze until it found the goal: The problem was that the teacher didn't explain the Hybrid A* algorithm - he just explained the classic A* algorithm , so I had to figure it out on my own...

Cybertruck Prototype vs Final Production Version - What Changed?

In 2019 I started making a 3D model of the Tesla Cybertruck prototype version in Blender. Four years later, in 2023, Elon Musk finally released the production version of the Cybertruck . Since I've studied every millimeter of the prototype version to be able to make the 3D model I thought it would be interesting to make a comparison of how much changed during the four years. Exterior Front bumper. The black front bumper has become bigger and smoother, most likely to improve the aerodynamics of the vehicle. They also added a mudguard for the front and rear wheels attached to it. Front window. Like the front bumper has become smoother to improve aerodynamics, so has the front window which is now rounded - it used to be completely flat (To be honest I think this is the case anyway - it is not rounded much to make it super visible). Wheels. The wheels are roughly the same as the prototype vehicle wheels - they added som threads to the side of the wheel. I thought t...

How to implement colormaps like Rainbow and Viridis in code

I've been working hard on making my very own digital wind tunnel in the Unity game engine. It's based on a tutorial from the YouTube series 10 Minute Physics called "How to write an Eulerian Fluid Simulator with 200 lines of code." I translated the code from JavaScript to C#, and I open sourced the implementation here: Ten Minute Physics in Unity. To simulate any fluid you need to study the Navier-Stokes equations . These are very hard to solve. In fact so hard they are a part of the Millennium Prize Problems where you can win a million dollars if you gain some insight while solving them. Therefore you need to simplify them. But even though they are simplified you can still see the vortex shedding that's happening in real wind tunnels if you put a cylinder in them. I thought this was really cool because the simulation part is just 200 lines of code running at 70 fps on the CPU. Common colormaps I wanted to improve the wind tunnel by making it more realistic...

Book review: How to fail at almost everything and still win big

You can today find Dilbert in 2000 newspapers in 65 countries. The comic strip Dilbert needs no introduction, but the author of the comic, Scott Adams, needs. To help us, he has written the book How to fail at almost everything and still win big - Kind of the story of my life . It was released in late 2013. The book is not a classic biography on Scott Adams's entire life - it's a book on how to improve your life based on the author's life experiences. But you will get a few glimpses into his life. You may first think that Scott Adams is only a cartoonist, but he's also an author and an entrepreneur, and has a broad background from several other endeavors. As the title suggests, Scott Adams has failed a lot. In the book he explains each failure in detail. The failures range from job interviews to computer games, from internet startups to stock picking, from health issues to failed corporate careers. But each failure taught him a new lesson, and with a little bit of help...

Thoughtful tweets by Nassim Nicholas Taleb

A Black Swan. Source: Wikipedia Nassim Nicholas Taleb is the author of books like Fooled by Randomness and The Black Swan . The latter book has nothing to do with the movie - it is a book about predictions. The basic idea is that it is impossible to predict the future since we can't predict Black Swan events. Once upon a time, everyone thought that if you looked at a swan, it had to be white. Then we discovered Australia and the black swans living there. There was no way someone could have predicted that swans also could be black by only looking at white swans in Europe. "One single observation can invalidate a general statement derived from millennia of confirmatory sighting of millions of white swans. All you need is one single black bird." When Nassim Nicholas Taleb is not writing books, he's using Twitter . If you don't follow him, you can find him under the Twitter-nickname @nntaleb . Compared with Warren Buffett ( @WarrenBuffett ), Nassim Nicholas Taleb is...