In the previous chapter, we covered how to use textures to add more detail to our 3D application. In this chapter, we'll learn how to interact with our WebGL application through a technique called picking. Picking refers to the ability to select objects in a 3D scene. The most common device used for picking is a computer mouse. However, picking can also be performed using other human computer interfaces, such as tactile screens and haptic devices. In this chapter, we will learn how picking can be implemented in WebGL.

In this chapter, you will:

• Learn how to select objects in a WebGL scene using the mouse.
• Create and use offscreen framebuffers.
• Learn what renderbuffers are and how they are used by framebuffers.
• Read pixels from framebuffers.
• Use color labels to perform object selection based on color.