Extensible 3D (X3D)
Part 1: Architecture and base components

Annex G


Recommended navigation behaviours

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cube G.1 Introduction and table of contents

This annex describes basic X3D scene navigation recommended practice. This recommended practice describes an X3D browser-independent standardized keyboard interface which implements X3D frequently used scene interactivity. Features that imply interactivity are fundamental in X3D. The author expects to be able to specify multiple viewpoints in a predicable sequence, the ability to point and select, and to enable continuous navigation within the scene. Likewise the interactor expects to be able to exercise scene functionality using predictable methods.

This recommended practice is intended to allow use of a core subset of the functionality of an X3D browser, not unnecessarily limit interactive functionality which may be provided by an X3D browser.

Table G.1 lists the major topics in this annex.

Table G.1 — Topics

cube G.2 Select from multiple viewpoints

User navigation in X3D environments includes definition of multiple viewpoints. Where the user is allowed to freely select between viewpoints, typical controls allow simple selection of:

This annex recommends using the following keys:

HOME    Initial Viewpoint 
PGDN    Next Viewpoint 
PGUP    Previous Viewpoint 
END     Final Viewpoint 

cube G.3 Emulate pointing device

The pointing device is used to control navigation through the scene. Where the user is allowed to interact using the pointing device, typical controls allow up/down/right/left pointing device movement to control movement of the viewpoint.

The objective is not to actually move the screen tracking cursor, but to allow navigation control as if the tracking cursor or pointer is moved under control of the pointing device.

This annex recommends using the following (arrow) keys to emulate relative tracking pointer movement as follows:

UP        Up  
DOWN      Down 
LEFT      Left
RIGHT     Right

Movement left/right/up/down refers to motion of the user's view while navigating.

Activation of these keys causes movement of the viewpoint according to currently selected navigation type:

WALK:      forward/backward/left/right
FLY:       forward/backward/left/right
EXAMINE:   orbit up/down/left/right around center of rotation
           with camera pointed at center of rotation

cube G.4 Select or activate pointing device

The pointing device is used to provide a means of selecting of a scene element. Where the user is allowed to use this, the following action is recommended: activate pointing device (left mouse click).

This annex recommends using the following key:

ENTER  Left Mouse Click

cube G.5 Disable/enable keyboard

It is recommended that the X3D browser provide a means for the author to enable and disable the keyboard.

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