How to hack any IR remote controller

If you haven’t heard of Air Swimmers before, you probably had a miserable life. Air Swimmers are inflatable foil balloons made in the shape of fish. But what makes them really awesome is the fact that they can be remotely controlled to fly around in a room. One of my friends, Claudio, developed an obsession interest for them; and that’s when we decided to create our own hackuarium.

The idea was simple: buying a bunch of Air Swimmers, hacking into their controllers and running a swarm simulation to control them. If you’re interested in doing the same and you have a basic knowledge of electronics …you’re reading the right post. At the end of this article you can find the links to buy all the necessary components.

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Extension methods in C#

Following the heritage of C++, C# comes with a number of powerful features which can either be used to massively improve your code …or to make it completely unreadable. In this post we’ll discuss a technique to add new methods to already existing classes. Yes, even classes you don’t have access to such as Vector3Rigidbody and even string. Let’s introduce extension methods with a practical example.

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Enum, Flags and bitwise operators

If you’re a game developer chances are you’re familiar with the need to describe different variations of an attribute. Whether it’s the type of an attack (melee, ice,  fire, poison, …) or the state of an enemy AI (idle, alerted, chasing, attacking, resting, …) you can’t escape this. The most naive way of implementing this is simply by using constants:

public static int NONE = 0;
public static int MELEE = 1;
public static int FIRE = 2;
public static int ICE = 3;
public static int POISON = 4;

public int attackType = NONE;

The downside is that you have no actual control over the values you can assign to attackType: it can be any integer, and you can also do dangerous things such as attackType++.

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How to Snap to Grid in Unity3D

Despite Unity3D being such an advanced framework, I am sometimes puzzled by its lack of basic features. Especially when working with 2D games, the lack of a proper snap to grid option is simply crazy. Luckily, Unity3D allows to extend its basic interface to add new behaviours. This post will explain how to add a customisable snap to grid option to your objects. Two different implementations are presented; the first one, despite being more complicated, could be used a good starting point to further extend and customise the inspector.

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Screen shaders and image effects in Unity3D

Part 1, Part 2, Part 3, Part 4, Part 5, [download the Unity3D package]

If you are using Unity3D you may be familiar with image effects. They are scripts which, once attached to a camera, alter its rendering output. Despite being presented as standard C# scripts, the actual computation is done using shaders. So far, materials have been applied directly to geometry; they can also be used to render offscreen textures, making them ideal for postprocessing techniques. When shaders are used in this fashion, they are often referred as screen shaders.

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Vertex and fragment shaders in Unity3D

Part 1, Part 2, Part 3, Part 4, Part 5, [download the Unity3D package]

The previous three posts of this tutorial have introduced surface shaders and how they can be used to specify physical properties (such as albedo, gloss and specular reflections) of the materials we want to model. The other type of shader available in Unity3D is called vertex and fragment shader. As the name suggests, the computation is done in two steps. Firstly, the geometry is passed through a function called (typically called vert) which can alter the position and data of each vertex. Then, the result goes through a frag function which finally outputs a colour.

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Physically Based Rendering and lighting models in Unity3D

Part 1, Part 2, Part 3, Part 4, Part 5, [download the Unity3D package]

Why is it colder at the poles and hotter on the equator? This question, which seems completely unrelated to shaders, is actually fundamental to understand how lighting models work. As explained in the previous part of this tutorial, surface shaders use a mathematical model to predict how light will reflect on triangles. Generally speaking, Unity supports two types of shading techniques, one for matte and one for specular materials. The former ones are perfect for opaque surfaces, while the latter ones simulate objects which reflections. The Maths behind these lighting models can get quite complicated, but understanding how they work is essential if you want to create your own, custom lighting effect. Up to Unity4.x, the default diffuse lighting model was based on the Lambertian reflectance. Continue reading

Surface shaders in Unity3D

Part 1, Part 2, Part 3, Part 4, Part 5

This is the second part of a series of posts on Unity3D shaders, and it will focus on surface shaders. As previously mentioned, shaders are special programs written in a language called Cg / HLSL which is executed by GPUs. They are used to draw triangles of your 3D models on the screen. Shaders are, in a nutshell, the code which represents how different materials are rendered. Surface shaders are introduced in Unity3D to simplify the way developers can define the look of their materials.

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A gentle introduction to shaders in Unity3D

Part 1, Part 2, Part 3, Part 4, Part 5

We can safely say that Unity3D has made game development easier for a lot of people. Something where it still has a long way to go is, with no doubt, shader coding. Often surrounded by mystery, a shader is a program specifically made to run on a GPU. It is, ultimately, what draws the triangles of your 3D models. Learning how to code shaders is essential if you want to give a special look to your game. Unity3D also uses them for postprocessing, making them essential for 2D games as well. This series of posts will gently introduce you to shader coding, and is oriented to developers with little to no knowledge about shaders.

Introduction

The diagram below loosely represents the three different entities which plays a role in the rendering workflow of Unity3D:

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How to retrieve all the images from a website

Few weeks ago I posted on Twitter few rather bizarre screenshots. A composition of all the submissions for #ScreenshotSaturday, loosely ordered by colour. In this series of posts I’ll briefly explain how I did that using Python.

You can download the original pictures (16Mb, 71Mb, 40Mb, 13Mb) here.

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