Chapter 22 - Background

Page Description
Figure 22.1 Background Sky Sphere A sky sphere with multiple colors.
Figure 22.2 Background Sky Ground A background with multiple ground and sky colors.
Figure 22.3c Background Sky Ground Mountains A mountain-panorama background created with the color and pixel transparency parts of a mountain image.
Figure 22.4 Background Binding Backgrounds bound and unbound by touching a red cube or a blue sphere.

http://www.web3d.org/x3d/content/examples/Vrml2.0Sourcebook/Chapter22-Background