trusty (3) SoVRMLNavigationInfo.3.gz
NAME
SoVRMLNavigationInfo -
The SoVRMLNavigationInfo class is used to specify avatar and viewer settings.
The detailed class documentation is taken verbatim from the VRML97 standard (ISO/IEC 14772-1:1997). It is
copyright The Web3D Consortium, and is used by permission of the Consortium:
SYNOPSIS
#include <Inventor/VRMLnodes/SoVRMLNavigationInfo.h>
Inherits SoNode.
Public Member Functions
virtual SoType getTypeId (void) const
Returns the type identification of an object derived from a class inheriting SoBase. This is used for
run-time type checking and 'downward' casting.
SoVRMLNavigationInfo (void)
virtual void GLRender (SoGLRenderAction *action)
Static Public Member Functions
static SoType getClassTypeId (void)
static void initClass (void)
Public Attributes
SoMFString type
SoSFFloat speed
SoMFFloat avatarSize
SoSFFloat visibilityLimit
SoSFBool headlight
Protected Member Functions
virtual const SoFieldData * getFieldData (void) const
virtual ~SoVRMLNavigationInfo ()
Static Protected Member Functions
static const SoFieldData ** getFieldDataPtr (void)
Protected Attributes
SoSFBool set_bind
SoSFBool isBound
Additional Inherited Members
Detailed Description
The SoVRMLNavigationInfo class is used to specify avatar and viewer settings.
The detailed class documentation is taken verbatim from the VRML97 standard (ISO/IEC 14772-1:1997). It is
copyright The Web3D Consortium, and is used by permission of the Consortium:
NavigationInfo {
eventIn SFBool set_bind
exposedField MFFloat avatarSize [0.25, 1.6, 0.75] # [0, inf)
exposedField SFBool headlight TRUE
exposedField SFFloat speed 1.0 # [0, inf)
exposedField MFString type ["WALK", "ANY"]
exposedField SFFloat visibilityLimit 0.0 # [0, inf)
eventOut SFBool isBound
}
The NavigationInfo node contains information describing the physical characteristics of the viewer's
avatar and viewing model. NavigationInfo node is a bindable node (see 4.6.10, Bindable children nodes:
http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/concepts.html#4.6.10). Thus,
there exists a NavigationInfo node stack in which the top-most NavigationInfo node on the stack is the
currently bound NavigationInfo node. The current NavigationInfo node is considered to be a child of the
current Viewpoint node regardless of where it is initially located in the VRML file. Whenever the current
Viewpoint nodes changes, the current NavigationInfo node shall be re-parented to it by the browser.
Whenever the current NavigationInfo node changes, the new NavigationInfo node shall be re-parented to the
current Viewpoint node by the browser. If a TRUE value is sent to the set_bind eventIn of a
NavigationInfo node, the node is pushed onto the top of the NavigationInfo node stack. When a
NavigationInfo node is bound, the browser uses the fields of the NavigationInfo node to set the
navigation controls of its user interface and the NavigationInfo node is conceptually re-parented under
the currently bound Viewpoint node. All subsequent scaling changes to the current Viewpoint node's
coordinate system automatically change aspects (see below) of the NavigationInfo node values used in the
browser (e.g., scale changes to any ancestors' transformations). A FALSE value sent to set_bind pops the
NavigationInfo node from the stack, results in an isBound FALSE event, and pops to the next entry in the
stack which shall be re-parented to the current Viewpoint node. 4.6.10, Bindable children nodes, has more
details on binding stacks (http://www.web3d.org/x3d/specifications/vrml/ISO-
IEC-14772-VRML97/part1/concepts.html#4.6.10).
The type field specifies an ordered list of navigation paradigms that specify a combination of navigation
types and the initial navigation type. The navigation type of the currently bound NavigationInfo node
determines the user interface capabilities of the browser. For example, if the currently bound
NavigationInfo node's type is 'WALK', the browser shall present a WALK navigation user interface paradigm
(see below for description of WALK). Browsers shall recognize and support at least the following
navigation types: 'ANY', 'WALK', 'EXAMINE', 'FLY', and 'NONE'.
If 'ANY' does not appear in the type field list of the currently bound NavigationInfo, the browser's
navigation user interface shall be restricted to the recognized navigation types specified in the list.
In this case, browsers shall not present a user interface that allows the navigation type to be changed
to a type not specified in the list. However, if any one of the values in the type field are 'ANY', the
browser may provide any type of navigation interface, and allow the user to change the navigation type
dynamically. Furthermore, the first recognized type in the list shall be the initial navigation type
presented by the browser's user interface.
ANY navigation specifies that the browser may choose the navigation paradigm that best suits the content
and provide a user interface to allow the user to change the navigation paradigm dynamically. The results
are undefined if the currently bound NavigationInfo's type value is 'ANY' and Viewpoint transitions (see
SoVRMLViewpoint) are triggered by the Anchor node (see SoVRMLAnchor) or the loadURL()scripting method
(see 4.12.10, Browser script interface: (http://www.web3d.org/x3d/specifications/vrml/ISO-
IEC-14772-VRML97/part1/concepts.html#4.6.10).
WALK navigation is used for exploring a virtual world on foot or in a vehicle that rests on or hovers
above the ground. It is strongly recommended that WALK navigation define the up vector in the +Y
direction and provide some form of terrain following and gravity in order to produce a walking or driving
experience. If the bound NavigationInfo's type is 'WALK', the browser shall strictly support collision
detection (see SoVRMLCollision).
FLY navigation is similar to WALK except that terrain following and gravity may be disabled or ignored.
There shall still be some notion of 'up' however. If the bound NavigationInfo's type is 'FLY', the
browser shall strictly support collision detection (see 6.8, Collision).
EXAMINE navigation is used for viewing individual objects and often includes (but does not require) the
ability to spin around the object and move the viewer closer or further away.
NONE navigation disables and removes all browser-specific navigation user interface forcing the user to
navigate using only mechanisms provided in the scene, such as Anchor nodes or scripts that include
loadURL().
If the NavigationInfo type is 'WALK', 'FLY', 'EXAMINE', or 'NONE' or a combination of these types (i.e.,
'ANY' is not in the list), Viewpoint transitions (see SoVRMLViewpoint) triggered by the Anchor node (see
SoVRMLAnchor) or the loadURL() scripting method shall be implemented as a jump cut from the old Viewpoint
to the new Viewpoint with transition effects that shall not trigger events besides the exit and enter
events caused by the jump.
Browsers may create browser-specific navigation type extensions. It is recommended that extended type
names include a unique suffix (e.g., HELICOPTER_mydomain.com) to prevent conflicts.
Viewpoint transitions (see SoVRMLViewpoint) triggered by the Anchor node (see SoVRMLAnchor) or the
loadURL() scripting method are undefined for extended navigation types. If none of the types are
recognized by the browser, the default 'ANY' is used. These strings values are case sensitive ('any' is
not equal to 'ANY').
The speed field specifies the rate at which the viewer travels through a scene in metres per second.
Since browsers may provide mechanisms to travel faster or slower, this field specifies the default,
average speed of the viewer when the NavigationInfo node is bound. If the NavigationInfo type is EXAMINE,
speed shall not affect the viewer's rotational speed. Scaling in the transformation hierarchy of the
currently bound Viewpoint node (see above) scales the speed; parent translation and rotation
transformations have no effect on speed. Speed shall be non-negative. Zero speed indicates that the
avatar's position is stationary, but its orientation and field of view may still change. If the
navigation type is 'NONE', the speed field has no effect.
The avatarSize field specifies the user's physical dimensions in the world for the purpose of collision
detection and terrain following. It is a multi-value field allowing several dimensions to be specified.
The first value shall be the allowable distance between the user's position and any collision geometry
(as specified by a Collision node ) before a collision is detected. The second shall be the height above
the terrain at which the browser shall maintain the viewer. The third shall be the height of the tallest
object over which the viewer can move. This allows staircases to be built with dimensions that can be
ascended by viewers in all browsers. The transformation hierarchy of the currently bound Viewpoint node
scales the avatarSize. Translations and rotations have no effect on avatarSize.
For purposes of terrain following, the browser maintains a notion of the down direction (down vector),
since gravity is applied in the direction of the down vector. This down vector shall be along the
negative Y-axis in the local coordinate system of the currently bound Viewpoint node (i.e., the
accumulation of the Viewpoint node's ancestors' transformations, not including the Viewpoint node's
orientation field).
Geometry beyond the visibilityLimit may not be rendered. A value of 0.0 indicates an infinite visibility
limit. The visibilityLimit field is restricted to be greater than or equal to zero.
The speed, avatarSize and visibilityLimit values are all scaled by the transformation being applied to
the currently bound Viewpoint node. If there is no currently bound Viewpoint node, the values are
interpreted in the world coordinate system. This allows these values to be automatically adjusted when
binding to a Viewpoint node that has a scaling transformation applied to it without requiring a new
NavigationInfo node to be bound as well. The results are undefined if the scale applied to the Viewpoint
node is non-uniform.
The headlight field specifies whether a browser shall turn on a headlight. A headlight is a directional
light that always points in the direction the user is looking. Setting this field to TRUE allows the
browser to provide a headlight, possibly with user interface controls to turn it on and off. Scenes that
enlist precomputed lighting (e.g., radiosity solutions) can turn the headlight off. The headlight shall
have intensity = 1, color = (1 1 1), ambientIntensity = 0.0, and direction = (0 0 -1).
It is recommended that the near clipping plane be set to one-half of the collision radius as specified in
the avatarSize field (setting the near plane to this value prevents excessive clipping of objects just
above the collision volume, and also provides a region inside the collision volume for content authors to
include geometry intended to remain fixed relative to the viewer). Such geometry shall not be occluded by
geometry outside of the collision volume.
Constructor & Destructor Documentation
SoVRMLNavigationInfo::SoVRMLNavigationInfo (void)
Constructor.
SoVRMLNavigationInfo::~SoVRMLNavigationInfo () [protected], [virtual]
Destructor.
Member Function Documentation
SoType SoVRMLNavigationInfo::getTypeId (void) const [virtual]
Returns the type identification of an object derived from a class inheriting SoBase. This is used for
run-time type checking and 'downward' casting. Usage example:
void foo(SoNode * node)
{
if (node->getTypeId() == SoFile::getClassTypeId()) {
SoFile * filenode = (SoFile *)node; // safe downward cast, knows the type
}
}
For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or
others: this method needs to be overridden in all subclasses. This is typically done as part of setting
up the full type system for extension classes, which is usually accomplished by using the pre-defined
macros available through for instance Inventor/nodes/SoSubNode.h (SO_NODE_INIT_CLASS and
SO_NODE_CONSTRUCTOR for node classes), Inventor/engines/SoSubEngine.h (for engine classes) and so on.
For more information on writing Coin extensions, see the class documentation of the toplevel superclasses
for the various class groups.
Implements SoBase.
const SoFieldData * SoVRMLNavigationInfo::getFieldData (void) const [protected], [virtual]
Returns a pointer to the class-wide field data storage object for this instance. If no fields are
present, returns NULL.
Reimplemented from SoFieldContainer.
void SoVRMLNavigationInfo::GLRender (SoGLRenderAction *action) [virtual]
Action method for the SoGLRenderAction.
This is called during rendering traversals. Nodes influencing the rendering state in any way or who wants
to throw geometry primitives at OpenGL overrides this method.
Reimplemented from SoNode.
Member Data Documentation
SoMFString SoVRMLNavigationInfo::type
Types of viewer. Possible values are 'WALK', 'ANY', 'EXAMINE', 'FLY' and 'NONE'. Is set to 'WALK' and
'ANY' by default.
SoSFFloat SoVRMLNavigationInfo::speed
Navigation speed. Default value is 1.0.
SoMFFloat SoVRMLNavigationInfo::avatarSize
Size of avatar. Default value is (0.25, 1.6, 0.75).
SoSFFloat SoVRMLNavigationInfo::visibilityLimit
Visibility limit. Default value is 0.0.
SoSFBool SoVRMLNavigationInfo::headlight
Specifies whether headlight should be enabled. Default value is TRUE.
Author
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