Introduction

Offscreen rendering functionality is a powerful feature of modern graphics API. In modern OpenGL, this is implemented by using the Framebuffer objects (FBOs). Some of the applications of the offscreen rendering include post processing effects such as glows, dynamic cubemaps, mirror effect, deferred rendering techniques, image processing techniques, and so on. Nowadays almost all games use this feature to carry out stunning visual effects with high rendering quality and detail. With the FBOs, the offscreen rendering is greatly simplified, as the programmer uses FBO the way he would use any other OpenGL object. This chapter will focus on using FBO to carry out image processing effects for implementing digital convolution and glow. In addition, we will also elaborate on how to use the FBO for mirror effect and dynamic cube mapping.