We have seen how processor-intensive producing special effects shots in Blender can be. However, it is possible to add the result from such tasks as a simple billboard render or animation. We saw in Chapter 3 how textures and movies can be applied as a sequenced texture when we created the television recipe and the red alert box. Pasting images to flat surfaces to represent something much more complex is known as billboard rendering. When you are creating a complex environment for your animated characters, it can be more effective to texture a simple plane with a background object rather than have to have many complex models to represent the background. In the old days, backgrounds in 2D animation were more frequently painted by very good matt artists.
With the advent of 3D animation systems, users began to discover that because you can apply an animated image to a plane, or another simple model, why not create animated billboard backgrounds....