# Reza Nourai's Game Development Ramblings

Random discussions about game development. Particularly math, physics, collision detection/response, and performance.
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• #### Barycentric Coordinates and Point in Triangle Tests

I know it’s been a little while since my last post, and I apologize. I’ll try and keep the posts a little more frequent moving forward. In the last post, we briefly encountered barycentric coordinates and loosely defined them as the coefficients...
• #### Math Primer Series: Vectors II: Vector Operations

In the last installment of this math primer, we looked at the difference between points and vectors. Today, we’ll dive a little bit deeper into vectors, and the specific operations we can perform on them. More importantly, we’ll take a look at...
• #### My First Post

The first post... what should I talk about? I guess a little about me, and a little about what's coming up in the blog. My name's Reza Nourai, and I'm a developer on the XNA Game Studio Team. I like video games... a lot! I like to play them, and I...
• #### Math Primer Series: Vectors III: Affine Spaces, Linear and Affine Combinations

In this chapter of our primer, we’ll examine affine spaces, and see what affine and linear combinations are. Furthermore, we can use these concepts to define some other related concepts, such as affine and linear dependency. Affine Space An...
• #### Math Primer Series: Matrices II: Linear Transformations

In the last installment of the math primer series, we looked at the basics of matrices. Today, we’ll take a look at using matrices for linear transformations, which are one of the most common uses of matrices in games. But, before we dive into linear...
• #### Math Primer Series: Intro, Notation, and References

This is the first part of a multi-part primer and reference for the math we’ll be using extensively throughout this blog. If you’ve been around game or graphics programming for any length of time, you’re probably at least somewhat familiar...
• #### Math Primer Series: Vectors I: Points vs. vectors

Some math and physics libraries contain separate data types to represent points and vectors. I’ve seen many people become confused by this, since more commonly packages use vectors exclusively for everything. What’s going on here? Why have 2 separate...

I apologize for the lack of updates in a while, but things have been pretty busy at work. I’m working on a new post and I’d love to get some feedback on what topics people want to see most in the future. Topics I have planned: Finish the math primer ...
• #### Intro to Physics in Games

I’ve decided to try something a bit different and mix in physics posts while I wrap up the math primer. Many of you might be more interested in the physics, or may already be familiar with the math topics, so this gives me a chance to have something for...
• #### Math Primer Series: Matrices III: Affine Transformations and Matrices

We’ve seen matrices used as representations of a basis, and we’ve seen them used as linear transformations, but what else can we do with them? So far, we’ve only been able to use matrices to transform vectors from one vector space to another. What about...
• #### Reviving the blog

As you may have heard, the Xbox One shipped! :) I spent the past 2 years working on various OS components for the Xbox One, including much of the multitasking work for the system (what allows you switch quickly from app to app, or from game to app...
• #### Math Primer Series: Rotation Representations and Quaternions

We saw the power and usefulness of transforms in the previous primer posts, and we’ll be using them quite a bit in our discussions of physics and graphics. One of the first tasks we’ll need to do is determine how to represent our transformations in code...