H3D::X3DViewpointNode Class Reference
[X3D node classes.]

The X3DViewpointNode node defines a specific location in the local coordinate system from which the user may view the scene. More...

#include <H3D/X3DViewpointNode.h>

Inheritance diagram for H3D::X3DViewpointNode:

Inheritance graph

List of all members.

Classes

class  SFOrientation
 This field is used for the orientation field in order to reset the internal variables rel_pos and rel_orn used for H3DAPIs internal navigation. More...
class  SFPosition
 This field is used for the position field in order to reset the internal variables rel_pos and rel_orn used for H3DAPIs internal navigation. More...
class  SFSumRotation
 This field sums the value of the two SFRotation routed to it. More...
class  SFSumVec3f
 This field sums the value of the two SFVec3f routed to it. More...

Public Member Functions

 X3DViewpointNode (Inst< SFSetBind > _set_bind=0, Inst< SFVec3f > _centerOfRotation=0, Inst< SFString > _description=0, Inst< SFBool > _jump=0, Inst< SFNode > _metadata=0, Inst< SFOrientation > _orientation=0, Inst< SFPosition > _position=0, Inst< SFBool > _retainUserOffsets=0, Inst< SFTime > _bindTime=0, Inst< SFBool > _isBound=0, Inst< SFMatrix4f > _accForwardMatrix=0, Inst< SFMatrix4f > _accInverseMatrix=0, Inst< SFSumVec3f > _totalPosition=0, Inst< SFSumRotation > _totalOrientation=0)
 Constructor.
virtual ~X3DViewpointNode ()
 Destructor.
virtual void traverseSG (TraverseInfo &ti)
 Traverse the scenegraph.
virtual void toStackTop ()
 Move this instance to the stack top.
virtual void removeFromStack ()
 Remove the bindable node from the stack.
virtual void rotateAround (Rotation rotation, bool collision, Vec3f rotation_center)
 Function for rotating the viewpoint around rotation_center without changing the position or orientation fields.
virtual void rotateAroundSelf (Rotation rotation)
 without changing the position or orientation fields.
virtual void translate (Vec3f direction, bool collision, const vector< H3DFloat > &avatar_size, X3DChildNode *topNode)
 Function for translating the viewpoint with direction without changing the position or orientation fields.
virtual void moveTo (Vec3f new_pos)
 Function for moving the viewpoint to the new_pos without changing the position or orientation fields.
virtual bool detectCollision (const vector< H3DFloat > &avatar_size, X3DChildNode *topNode)
 Function for detecting collision between avatar and objects.

Static Public Member Functions

static X3DViewpointNodegetActive ()
 Convenience function to get the top of the X3DViewpointNode stack.
static const ViewpointList & getAllViewpoints ()
 Returns a list of all current X3DViewpointNode instances.
static ViewpointList getViewpointHierarchy ()
 Get the all X3DViewpointNode instances with the X3DViewpointNode that are in ViewpointGroup only present in the group and not by them self in the list.

Public Attributes

auto_ptr< SFVec3fcenterOfRotation
 The centerOfRotation field specifies a center about which to rotate the user's eyepoint when in EXAMINE mode.
auto_ptr< SFStringdescription
 The description field specifies a textual description of the X3DViewpointNode node.
auto_ptr< SFBooljump
 The jump field specifies whether the user's view "jumps" to the position and orientation of a bound X3DViewpointNode node or remains unchanged.
auto_ptr< SFOrientationorientation
 Specifies the orientation of the X3DViewpointNode relative to the default orientation.
auto_ptr< SFPositionposition
 Specifies the position of the X3DViewpointNode the local coordinate system.
auto_ptr< SFBoolretainUserOffsets
 The retainUserOffsets field indicates whether a viewpoint needs to retain (TRUE) or reset to zero (FALSE) any prior user navigation offsets from defined viewpoint position, orientation.
auto_ptr< SFMatrix4faccForwardMatrix
 The matrix from local space to global space.
auto_ptr< SFMatrix4faccInverseMatrix
 The matrix from global space to the local space the X3DViewpointNode resides in.
auto_ptr< SFSumVec3ftotalPosition
 Returns the sum of the field position and the internal field relPos used for navigation.
auto_ptr< SFSumRotationtotalOrientation
 Returns the sum of the field orientation and the internal field relOrn used for navigation.
auto_ptr< SFVec3frelPos
 Internal field that stores the relative offset from the position set by the user.
auto_ptr< SFRotationrelOrn
 Internal field that stores the relative offset from the orientation set by the user.

Static Public Attributes

static H3DNodeDatabase database
 The H3DNodedatabase for this node.


Detailed Description

The X3DViewpointNode node defines a specific location in the local coordinate system from which the user may view the scene.

X3DViewpointNode nodes are bindable children nodes (see X3DBindableNode) and thus there exists a X3DViewpointNode node stack in which the top-most X3DViewpointNode node on the stack is the currently active X3DViewpointNode node. If a TRUE value is sent to the set_bind field of a X3DViewpointNode node, it is moved to the top of the X3DViewpointNode node stack and activated. When a X3DViewpointNode node is at the top of the stack, the user's view is conceptually re-parented as a child of the X3DViewpointNode node. All subsequent changes to the X3DViewpointNode node's coordinate system change the user's view (e.g., changes to any ancestor transformation nodes or to the X3DViewpointNode node's position or orientation fields). Sending a set_bind FALSE event removes the X3DViewpointNode node from the stack and produces isBound FALSE and bindTime events. If the popped X3DViewpointNode node is at the top of the X3DViewpointNode stack, the user's view is re-parented to the next entry in the stack. When a X3DViewpointNode node is moved to the top of the stack, the existing top of stack X3DViewpointNode node sends an isBound FALSE event and is pushed down the stack.

An author can automatically move the user's view through the world by binding the user to a X3DViewpointNode node and then animating either the X3DViewpointNode node or the transformations above it. The bindTime field sends the time at which the X3DViewpointNode node is bound or unbound. This can happen:

The position and orientation fields of the X3DViewpointNode node specify relative locations in the local coordinate system. Position is relative to the coordinate system's origin (0,0,0), while orientation specifies a rotation relative to the default orientation. In the default position and orientation, the viewer is on the Z-axis looking down the Z-axis toward the origin with +X to the right and +Y straight up. X3DViewpointNode nodes are affected by the transformation hierarchy.

Navigation types (see NavigationInfo) that require a definition of a down vector (e.g., terrain following) shall use the negative Y-axis of the coordinate system of the currently bound X3DViewpointNode node. Likewise, navigation types that require a definition of an up vector shall use the positive Y-axis of the coordinate system of the currently bound X3DViewpointNode node. The orientation field of the X3DViewpointNode node does not affect the definition of the down or up vectors. This allows the author to separate the viewing direction from the gravity direction.

The jump field specifies whether the user's view "jumps" to the position and orientation of a bound X3DViewpointNode node or remains unchanged. This jump is instantaneous and discontinuous in that no collisions are performed and no ProximitySensor nodes are checked in between the starting and ending jump points. If the user's position before the jump is inside a ProximitySensor the exitTime of that sensor shall send the same timestamp as the bind field. Similarly, if the user's position after the jump is inside a ProximitySensor the enterTime of that sensor shall send the same timestamp as the bind field. Regardless of the value of jump at bind time, the relative viewing transformation between the user's view and the current X3DViewpointNode node shall be stored with the current X3DViewpointNode node for later use when un-jumping (i.e., popping the X3DViewpointNode node binding stack from a X3DViewpointNode node with jump TRUE). The following summarizes the bind stack rules (X3DBindableNode) with additional rules regarding X3DViewpointNode nodes:

The jump field may change after a X3DViewpointNode node is bound. The rules described above still apply. If jump was TRUE when the X3DViewpointNode node is bound, but changed to FALSE before the set_bind FALSE is sent, the X3DViewpointNode node does not un-jump during unbind. If jump was FALSE when the X3DViewpointNode node is bound, but changed to TRUE before the set_bind FALSE is sent, the X3DViewpointNode node does perform the un-jump during unbind.

Note that there are two other mechanisms that result in the binding of a new X3DViewpointNode:

Both of these mechanisms override the jump field value of the specified X3DViewpointNode node (X3DViewpointNodeName) and assume that jump is TRUE when binding to the new X3DViewpointNode. The behaviour of the viewer transition to the newly bound X3DViewpointNode depends on the currently bound NavigationInfo node's type field value.

The fieldOfView field specifies a preferred minimum viewing angle from this X3DViewpointNode in radians. A small field of view roughly corresponds to a telephoto lens; a large field of view roughly corresponds to a wide-angle lens. The field of view shall be greater than zero and smaller than ?. The value of fieldOfView represents the minimum viewing angle in any direction axis perpendicular to the view. For example, a browser with a rectangular viewing projection shall have the following relationship:

display width tan(FOVhorizontal/2)
-------------- = -----------------
display height tan(FOVvertical/2)

where the smaller of display width or display height determines which angle equals the fieldOfView (the larger angle is computed using the relationship described above). The larger angle shall not exceed ? and may force the smaller angle to be less than fieldOfView in order to sustain the aspect ratio.

The description field specifies a textual description of the X3DViewpointNode node. This may be used by browser-specific user interfaces. If a X3DViewpointNode's description field is empty it is recommended that the browser not present this X3DViewpointNode in its browser-specific user interface.

The centerOfRotation field specifies a center about which to rotate the user's eyepoint when in EXAMINE mode. If the browser does not provide the ability to spin around the object in EXAMINE mode, or LOOKAT is not in the list of allowed navigation modes, this field shall be ignored.

The URL syntax ".../scene.wrl#X3DViewpointNodeName" specifies the user's initial view when loading "scene.wrl" to be the first X3DViewpointNode node in the X3D file that appears as DEF X3DViewpointNodeName X3DViewpointNode {...}. This overrides the first X3DViewpointNode node in the X3D file as the initial user view, and a set_bind TRUE message is sent to the X3DViewpointNode node named "X3DViewpointNodeName". If the X3DViewpointNode node named "X3DViewpointNodeName" is not found, the browser shall use the first X3DViewpointNode node in the X3D file (i.e. the normal default behaviour). The URL syntax "#X3DViewpointNodeName" (i.e. no file name) specifies a X3DViewpointNode within the existing X3D file. If this URL is loaded (e.g. Anchor node's url field or loadURL() method is invoked by a Script node), the X3DViewpointNode node named "X3DViewpointNodeName" is bound (a set_bind TRUE event is sent to this X3DViewpointNode node).

The retainUserOffsets field indicates whether a viewpoint needs to retain (TRUE) or reset to zero (FALSE) any prior user navigation offsets from defined viewpoint position, orientation. When an node of type X3DViewpointNode is bound, user navigation offsets are reinitialized if the associated retainUserOffsets is TRUE.

Internal routes:
X3DViewpointNode.dot

Member Function Documentation

X3DViewpointNode::ViewpointList X3DViewpointNode::getViewpointHierarchy (  )  [static]

Get the all X3DViewpointNode instances with the X3DViewpointNode that are in ViewpointGroup only present in the group and not by them self in the list.

void X3DViewpointNode::moveTo ( Vec3f  new_pos  )  [virtual]

Function for moving the viewpoint to the new_pos without changing the position or orientation fields.

References position, and relPos.

void X3DViewpointNode::rotateAround ( Rotation  rotation,
bool  collision,
Vec3f  rotation_center 
) [virtual]

Function for rotating the viewpoint around rotation_center without changing the position or orientation fields.

Parameters:
rotation The rotation to be applied.
collision If true then collision between avatar and nodes will be considered. NOTE: Not used in current implementation.
rotation_center The center of rotation.

References H3DUtil::ArithmeticTypes::Rotationd::angle, H3DUtil::ArithmeticTypes::Rotationd::axis, orientation, position, relOrn, relPos, and Rotation().

void X3DViewpointNode::translate ( Vec3f  direction,
bool  collision,
const vector< H3DFloat > &  avatar_size,
X3DChildNode topNode 
) [virtual]

Function for translating the viewpoint with direction without changing the position or orientation fields.

Parameters:
direction The translation vector.
collision If true then collision between avatar and nodes will be considered.
avatar_size Information about how the avatar is specified.
topNode needed for collision detection.

References accForwardMatrix, H3DSqrt(), H3D::Node::movingSphereIntersect(), orientation, position, relOrn, and relPos.

virtual void H3D::X3DViewpointNode::traverseSG ( TraverseInfo ti  )  [inline, virtual]

Traverse the scenegraph.

Saves the accumulated inverse matrix for later use when transforming the X3DViewpointNode in GLWindow.

Parameters:
ti The TraverseInfo object containing information about the traversal.

Reimplemented from H3D::Node.

Reimplemented in H3D::ViewpointGroup.

References H3D::TraverseInfo::getAccForwardMatrix(), and H3D::TraverseInfo::getAccInverseMatrix().


Member Data Documentation

The matrix from global space to the local space the X3DViewpointNode resides in.

Access type: outputOnly

X3DViewpointNode_accInverseMatrix.dot

Referenced by removeFromStack(), H3D::H3DWindowNode::render(), toStackTop(), and X3DViewpointNode().

The centerOfRotation field specifies a center about which to rotate the user's eyepoint when in EXAMINE mode.

Access type: inputOutput
Default value: Vec3f( 0, 0, 0 )

X3DViewpointNode_centerOfRotation.dot

Referenced by H3D::ProximitySensor::traverseSG(), and X3DViewpointNode().

The description field specifies a textual description of the X3DViewpointNode node.

Access type: inputOutput
Default value: ""

X3DViewpointNode_description.dot

The jump field specifies whether the user's view "jumps" to the position and orientation of a bound X3DViewpointNode node or remains unchanged.

Access type: inputOutput
Default value: TRUE

X3DViewpointNode_jump.dot

Referenced by removeFromStack(), toStackTop(), and X3DViewpointNode().

Specifies the orientation of the X3DViewpointNode relative to the default orientation.

Per default the viewer is on the Z-axis looking down the -Z-axis toward the origin with +X to the right and +Y straight up.

Access type: inputOutput
Default value: Rotation( 0, 0, 1, 0 )

X3DViewpointNode_orientation.dot

Referenced by removeFromStack(), rotateAround(), rotateAroundSelf(), toStackTop(), translate(), and X3DViewpointNode().

Specifies the position of the X3DViewpointNode the local coordinate system.

Access type: inputOutput
Default value: Vec3f( 0, 0, 10 )

X3DViewpointNode_position.dot

Referenced by moveTo(), removeFromStack(), rotateAround(), toStackTop(), translate(), and X3DViewpointNode().

Internal field that stores the relative offset from the orientation set by the user.

Set while navigating. The actual orientation of the viewpoint can be obtained through the totalOrientation field.

Referenced by removeFromStack(), rotateAround(), rotateAroundSelf(), toStackTop(), translate(), H3D::X3DViewpointNode::SFOrientation::update(), H3D::X3DViewpointNode::SFPosition::update(), and X3DViewpointNode().

Internal field that stores the relative offset from the position set by the user.

Set while navigating. The actual position of the viewpoint can be obtained through the totalPosition field.

Referenced by moveTo(), removeFromStack(), rotateAround(), toStackTop(), translate(), H3D::X3DViewpointNode::SFOrientation::update(), H3D::X3DViewpointNode::SFPosition::update(), and X3DViewpointNode().

The retainUserOffsets field indicates whether a viewpoint needs to retain (TRUE) or reset to zero (FALSE) any prior user navigation offsets from defined viewpoint position, orientation.

Access type: inputOutput
Default value: false

X3DViewpointNode_retainUserOffsets.dot

Referenced by toStackTop(), and X3DViewpointNode().


The documentation for this class was generated from the following files:

Generated on Fri Nov 7 10:31:35 2008 for H3D API by  doxygen 1.5.7