The Heads-up Display (HUD) world illustrates creation of a heads-up display that is locked in place to the screen. Such positioning is done by using proximity sensor translation and rotation output to position and orient a set of shapes every time the viewer moves. That set of shapes can include anything. In this example, that set of shapes includes a thumb wheel with which world content can be rotated, and a pair of start and stop buttons that control an animation of that content.
Vrml97ToX3dNist, http://ovrt.nist.gov/v2_x3d.html
X3D-Edit, https://www.web3d.org/x3d/tools/X3D-Edit
"grill.png" "https://www.web3d.org/x3d/content/examples/Vrml2Sourcebook/Siggraph98Course/grill.png"
"start.jpg" "https://www.web3d.org/x3d/content/examples/Vrml2Sourcebook/Siggraph98Course/start.jpg"
"stop.jpg" "https://www.web3d.org/x3d/content/examples/Vrml2Sourcebook/Siggraph98Course/stop.jpg"