In this article I will attempt to explain the concept of Quaternions in an easy to understand way. I will explain how you might visualize a Quaternion as well as explain the different operations that can be applied to quaternions. I will also compare applications of matrices, euler angles, and quaternions and try to explain when you would want to use quaternions instead of Euler angles or matrices and when you would not.

# Author Archives: Jeremiah

# Transformation and Lighting in Cg 3.1

In this article I will demonstrate how to implement a basic lighting model using the Cg shader language. If you are unfamiliar with using Cg in your own applications, then please refer to my previous article titled Introduction to Shader Programming with Cg 3.1.

This article is an updated version of the previous article titled Transformation and Lighting in Cg. In this article, I will not use any deprecated features of OpenGL. I will only use the core OpenGL 3.1 API.

# Introduction to Shader Programming with Cg 3.1

In this article I will introduce the reader to shader programming using the Cg shader programming language. I will use OpenGL graphics API to communicate with the Cg shaders. This article does not explain how use OpenGL. If you require an introduction to OpenGL, you can follow my previous article titled Introduction to OpenGL.

# Using OpenGL Vertex Buffer Objects

**ARB_vertex_buffer_object**extension to efficiently render geometry in OpenGL.

If you are not sure how to use extensions in OpenGL, you can refer to my previous article titled OpenGL Extensions. If you have never programmed an OpenGL application before, you can refer to my previous article titled Introduction to OpenGL.

# OpenGL Extensions

**GLEW**to query and use extensions with very little extra effort.

I assume the reader is familiar with the C++ programming language. If you want to know how to start programming in OpenGL, refer to my previous article titled Introduction to OpenGL.

# Texturing and Lighting in OpenGL

I assume that the reader has a basic knowledge of C++ and how to create and compile C++ programs. If you have never created an OpenGL program, then I suggest that you read my previous article titled “Introduction to OpenGL” here before continuing with this article.

# Rendering Primitives with OpenGL

# CUDA Case Study – N-Body Simulation

In this post, I will analyze the CUDA implementation of the N-Body simulation. The implementation that I will be using as a reference for this article is provided with the CUDA GPU Computing SDK 10.2. The source code for this implementation is available in the “%NVCUDASAMPLES_ROOT%\5_Simulations\nbody” in the GPU Computing SDK 10.2 samples base folder.

I assume the reader has a good understanding of the CUDA programming API.

# Introduction to OpenCL

In this article I will provide a brief introduction to OpenCL. OpenCL is a open standard for general purpose parallel programming across CPUs, GPUs, and other programmable parallel devices. I assume that the reader is familiar with the C/C++ programming languages. I will use Microsoft Visual Studio 2008 to show how you can setup a project that is compiled with the OpenCL API.