Yarn Editor and Yarn Spinner is a framework for creating conversations easily, created by the authors of Night In The Woods. You create them as a tree of nodes, save it as json and the framework takes care of the rest.

Everyone thought about having telekinesis as a kid. Why not fulfill that fantasy and actually give yourself that power, in a game? If you ever wondered how games like Control or Psi Ops: Mindgate conspiracy do it, you’ve come to the right place. It’s easier than you think!

In this part I will show you how to generate enemies on the NavMesh. I will make them chase me and collide with objects properly.

If you ever wanted to make Space Invaders in Python, but were too lazy to do it, here’s a short tutorial with GIFS!

This is a second part of my gamedev series. For setting up walking (and other animations) see the first part.

Several years ago a revolutionary technology called blockchain showed up on the scene. It’s probably the biggest invention since the creation of the Internet. The first cryptocurrency using the blockchain was Bitcoin and since then, thousands of other alternative coins arose. Blockchain has no central point of failure, so it’s very difficult for authorities and corporations to control or regulate it. In this article we are going to take a look at the inner workings of the blockchain technology, its security, ways of storing bitcoin, and the meaning of the Bitcoin halving that happened last week. Note: “Bitcoin” references the network and the payment system, “bitcoin” references the currency and the currency unit.

Blockchain

Cryptocurrencies represents a type of decentralization, which takes the power over money away from the banks. Thanks to the blockchain, no institution can directly tamper with the cryptocurrency progression. One of the primary goals of the Bitcoin blockchain is to provide people with a secure way to store money, so if another financial crisis was to come, your funds would stay safe and independent of the banking system. Blockchain is a globally distributed ledger, implemented as a chain of blocks. Each block stores the completed transactions using strong cryptographic functions in a way that it’s practically impossible to hack. Almost anything can be saved on the blockchain, and it’s possible to do so without any third parties — the value is transferred directly between people and nobody is taking any fees, at least not directly (more on that below). Everything that was stored in the blockchain will remain unchangeable and permanent due to the high cryptographic security of the blockchain. It‘s politically and architecturally decentralized, so it cannot be controlled or regulated by any institution. It’s divided into multiple computational units, typically a global network of computers. But logically it is centralized, because it behaves like a single entity, like a powerful supercomputer — doing only a single set of tasks.

Bitcoin “Halvening”

Bitcoin is created when a new block is mined. More precisely, the reward is given to the miner who found the right “solution of the block” (hash). The reward is currently 6.25 bitcoin + all of the transaction fees in the block. The reward is halving every 210000 blocks (so every 4 years (1 block ~= 10 minutes)), so next time it will be 3.125 bitcoin in 2024. Presumably the price of bitcoin will be way higher at that time. (Previous block reward was 12.5 BTC, so 12.5BTC@9395USD = 117,437 USD) The transaction fee can be specified by the user, but the miners will of course prioritize the higher fee transactions, because it means a higher reward for them. When you use a low tx fee, you can wait dozens of blocks (or hundreds of minutes (1 block ~= 10 minutes). In any case, it’s still a better score than bank payment has — you have to wait anywhere between a few days to a few weeks, considering the overseas payments. Alternative coins (altcoins), i.e. Litecoin or Dogecoin have the time on the block set to lower values, LTC is on average 2.5 minutes and DOGE a minute.

Difficulty and Mining

Solo mining is already obsolete today. The difficulty of finding one bitcoin on your own, using your hardware, is about the same as searching for one particular seed of sand on the whole Planet Earth. That is why the miners started to form groups, so-called pools, where is their computational power shared for mining bitcoins. When they are successful, the found coin is democratically shared between everyone, depending on the work done.

The current computational power of the Bitcoin blockchain is ~120 Exahash/s. That means you would need at least 60 Exahash/s super-computer to do the 51% attack.

The strongest super-computer in the world, Summit, operates on 144 Petaflops. Taken that 1 hash/s is ~12700 flops/s, you would need a few million super-computers to change ONE transaction in the blockchain.

Brazilian Jiu Jitsu, or BJJ for short, is a martial art that some people call “human chess” for its complexity. It’s one of the most complex martial arts and it could take years to reach the black belt even for a skilled wrestler. I’ve never been in a real fight in my life. And so I never really learned how to properly defend myself. That started being a problem even in my professional life. There once came a moment, where I had to make a call with a CEO of a big online project, which we had to migrate to our servers. And I realized I am too afraid, for some reason, to make the call. I procrastinated with it for about an hour, even when I knew it would take only a minute. When I finally made the call, it turned out fine. No problem. Smooth. But I knew I have to change something to be more confident next time. There was no logical reason for me to be afraid, but I still was. Then I had some problems with my boss. Lot of the time I came up with a proper response to defend myself a few minutes after I needed to say it. That needed to stop. I never knew that my inability to properly physically defend myself translated so much to everyday interactions. Then, one day, a though popped into my mind: “What if I sign up for judo classes?” I had some defense training before, but it was mostly just krav maga and karate techniques, that I forgot few months after. This time I wanted to go all in. I googled some judo videos and found this beautiful montage, that made me motivated to really get into martial arts. I called the first judo instructor I found in my city, but he was irritated during the call and I felt he had some kind of a problem with answering my questions about the process. Not only that, but the phone call had an interference. That was enough of a sign for me to look elsewhere. I found only judo lessons starting in a few months, and I wanted to get in now. So I had to try something else. JIU JITSU. Yes, that’s it! I’ve heard about it before. The most complex martial art on the planet. That should even stimulate my “intellectual” needs. So I called a BJJ instructor, and he sounded all welcoming, friendly, warm and invited me to a free Sunday lesson. When I was all nervous about it, and told him I don’t have a kimono, he told me he will borrow me one of his; that all I have to do is to come and try it. And that was it. I was sold. The first lesson was amazing. 1 hour of techniques and 1 hour of sparring fights. I had my first hour of full blown jiu jitsu sparring. It was simply awesome. And I was so exhausted after, that I had to vomit. But it wasn’t uncomfortable. It was like a cathartic vomit. It felt great. I started coming in more. My fingers and knuckles were all bloody, and arms hurt from the armbars, neck and throat hurt from strangling, but that didn’t stop me. I kept coming in twice a week. I felt like Tyler Durden. Finally having a real fight. I tried some weeks where I went 3 times, but those were too damaging. It felt great to get really strangled. It felt great to fight to defend myself from it, even when the opponent had 40 KG more. I needed all of this. I became addicted to it fast. But it took me about 15 lessons to “get comfortable” with hurting others. In the first lessons I learned how to defend myself, to not get submitted immediately and to last at least to the end of the round before I rotate to another sparring partner. Then I finally started attacking and doing my first submissions. All I had to do is to keep in mind the basic techniques and defenses, and attack when there was a window to do so. It always comes with a thrill that I will get punished for my attack, if the opponent is more experienced then I thought. It’s all very complex and I see I am just at the beginning of it all. But it felt incredible to strangle an opponent into submission for the first time, with Ezekiel Choke. But after mere 50 hours of Jiu Jitsu, I can tell that I gained some considerable confidence in myself. Now I almost immediately feel when someone is talking down to me, being passive aggressive or has some manipulative intentions with me, and I can defend myself and attack back. Not only that, but my fitness level is the best I’ve ever had in my life. I always had sedentary jobs in the office and didn’t have any sports I would like. I tried some sports, but didn’t really like any. Going to the gym was just too boring and repetitive for me. I saw no meaning in it. But Jiu Jitsu? Not only is it a great cardio exercise, but it strengthens your inner Warrior archetype, reinforces your willpower and you learn how to properly defend yourself. The complexity of it ensures that you will never run out of things to learn in this sport. And as the saying goes:

“Black belts are just white belts who didn’t quit”

In this article I will analyze mythological concepts and symbols used in the Harry Potter franchise.