XdkWrl: Transform Class Reference

6.71 Transform

The Transform node is a grouping node that defines a coordinate system for its children that is relative to the coordinate systems of its ancestors. See 4.4.4, Transformation hierarchy, and 4.4.5, Standard units and coordinate system, for a description of coordinate systems and transformations.

4.6.5, Grouping and children nodes, provides a description of the children, addChildren, and removeChildren fields and eventIns.

The bboxCenter and bboxSize fields specify a bounding box that encloses the children of the Transform node. This is a hint that may be used for optimization purposes. The results are undefined if the specified bounding box is smaller than the actual bounding box of the children at any time. A default bboxSize value, (-1, -1, -1), implies that the bounding box is not specified and, if needed, shall be calculated by the browser. The bounding box shall be large enough at all times to enclose the union of the group's children's bounding boxes; it shall not include any transformations performed by the group itself (i.e., the bounding box is defined in the local coordinate system of the children). The results are undefined if the specified bounding box is smaller than the true bounding box of the group. A description of the bboxCenter and bboxSize fields is provided in 4.6.4, Bounding boxes.

The translation, rotation, scale, scaleOrientation and center fields define a geometric 3D transformation consisting of (in order):

a (possibly) non-uniform scale about an arbitrary point;
a rotation about an arbitrary point and axis;
a translation.

The center field specifies a translation offset from the origin of the local coordinate system (0,0,0). The rotation field specifies a rotation of the coordinate system. The scale field specifies a non-uniform scale of the coordinate system. scale values shall be greater than zero. The scaleOrientation specifies a rotation of the coordinate system before the scale (to specify scales in arbitrary orientations). The scaleOrientation applies only to the scale operation. The translation field specifies a translation to the coordinate system.

Given a 3-dimensional point P and Transform node, P is transformed into point P' in its parent's coordinate system by a series of intermediate transformations. In matrix transformation notation, where C (center), SR (scaleOrientation), T (translation), R (rotation), and S (scale) are the equivalent transformation matrices,

    P' = T × C × R × SR × S × -SR × -C × P

The following Transform node:

Transform { 
    center           C
    rotation         R
    scale            S
    scaleOrientation SR
    translation      T
    children         [...]
}

is equivalent to the nested sequence of:

Transform {
  translation T 
  children Transform {
    translation C
    children Transform {
      rotation R
      children Transform {
        rotation SR 
        children Transform {
          scale S 
          children Transform {
            rotation -SR 
            children Transform {
              translation -C
              children [...]
}}}}}}}

Constructor & Destructor Documentation

Transform ( const char * name = "" )

Construct a node with all its fields set to default value, which is equivalent to the code below:

  center.setXYZ(0,0,0);
  rotation.setAxisAndAngle(0,0,1,0);
  scale.setXYZ(1,1,1);
  scaleOrientation.setAxisAndAngle(0,0,1,0);
  translation.setXYZ(0,0,0);
  bboxCenter.setXYZ(0,0,0);
  bboxSize.setXYZ(-1,-1,-1);

Member Function Documentation

wrl::Node * duplicate ( std::map< const Node *, Node * > & ) const [virtual]

Implements Node.

wrl::Node * duplicate ( ) const [virtual]

Returns a deep copy of this node, that is a fully independant node with all children (if any) also copied. This is mainly useful for instanciating protos.

Implements Node.

wrl::Node::EventInHandle eventIn ( const unsigned int n ) [virtual]

Return a handle on the i th event in of the node or a "unknown" typed handle if there is no such node. Here is how i is related to fields:

0 : addChildren
1 : removeChildren
2 : set_center
3 : set_children
4 : set_rotation
5 : set_scale
6 : set_scaleOrientation
7 : set_translation

This function is useful, with nbEventsIn() if you want to traverse all events in of a Node.

Implements Node.

wrl::Node::EventInHandle eventIn ( const std::string & n ) [virtual]

Return a handle on the event in named n of the node or a "unknown" typed handle if there is no such event. Valid names are:

addChildren
removeChildren
set_center
set_children
set_rotation
set_scale
set_scaleOrientation
set_translation

Implements Node.

wrl::Node::EventOutHandle eventOut ( const unsigned int n ) [virtual]

Return a handle on the i th event out of the node or a "unknown" typed handle if there is no such node. Here is how i is related to fields:

0 : center_changed
1 : children_changed
2 : rotation_changed
3 : scale_changed
4 : scaleOrientation_changed
5 : translation_changed This function is useful, with nbEventsOut() if you want to traverse all events in of a Node.

Implements Node.

wrl::Node::EventOutHandle eventOut ( const std::string & n ) [virtual]

Return a handle on the event out named n of the node or a "unknown" typed handle if there is no such event. Valid names are:

center_changed
children_changed
rotation_changed
scale_changed
scaleOrientation_changed
translation_changed

Implements Node.

wrl::Node::FieldHandle field ( const unsigned int n ) [virtual]

Return a handle on the i th field of the node or a "unknown" typed handle if there is no such node. Here is how i is related to fields:

0 : center
1 : children
2 : rotation
3 : scale
4 : scaleOrientation
5 : translation
6 : bboxCenter
7 : bboxSize This function is useful, with nbFields() if you want to traverse all fields of a Node.

Implements Node.

wrl::Node::FieldHandle field ( const std::string & n ) [virtual]

Return a handle on the field named n of the node or a "unknown" typed handle if there is no such field. Valid names are:

center
children
rotation
scale
scaleOrientation
translation
bboxCenter
bboxSize

Implements Node.

bool isSetToDefaultValue ( const unsigned int i ) const [virtual]

Implements Node.

unsigned int nbEventsIn ( ) const [inline, virtual]

Returns the number of events in for this node type.

Implements Node.

unsigned int nbEventsOut ( ) const [inline, virtual]

Returns the number of events out for this node type.

Implements Node.

unsigned int nbFields ( ) const [inline, virtual]

Returns the number of fields (exposed or not) for this node type.

Implements Node.

const char * typeName ( ) const [inline, virtual]

Returns "Transform". Useful for printing.

Implements Node.


Public Member Functions
	Transform (const char *name="")
virtual	~Transform ()
virtual unsigned int	nbFields () const
virtual FieldHandle	field (const std::string &n)
virtual FieldHandle	field (const unsigned int i)
virtual bool	isSetToDefaultValue (const unsigned int i) const
virtual unsigned int	nbEventsIn () const
virtual EventInHandle	eventIn (const std::string &n)
virtual EventInHandle	eventIn (const unsigned int i)
virtual unsigned int	nbEventsOut () const
virtual EventOutHandle	eventOut (const std::string &n)
virtual EventOutHandle	eventOut (const unsigned int i)
const char *	typeName () const
virtual Node *	duplicate () const
virtual Node *	duplicate (std::map< const Node , Node > &) const
Public Attributes
Exposed Fields
A field that is capable of receiving events via an eventIn to change its value(s), and generating events via an eventOut when its value(s) change.
SFVec3f	center
MFNode	children
SFRotation	rotation
SFVec3f	scale
SFRotation	scaleOrientation
SFVec3f	translation
Fields
A property or attribute of a node. Each node type has a fixed set of fields. Fields may contain various kinds of data and one or many values. Each field has a default value.
SFVec3f	bboxCenter
SFVec3f	bboxSize
Events In
EventIn< MFNode >	addChildren
EventIn< MFNode >	removeChildren
EventIn< SFVec3f >	set_center
EventIn< MFNode >	set_children
EventIn< SFRotation >	set_rotation
EventIn< SFVec3f >	set_scale
EventIn< SFRotation >	set_scaleOrientation
EventIn< SFVec3f >	set_translation
Events Out
EventOut< SFVec3f >	center_changed
EventOut< MFNode >	children_changed
EventOut< SFRotation >	rotation_changed
EventOut< SFVec3f >	scale_changed
EventOut< SFRotation >	scaleOrientation_changed
EventOut< SFVec3f >	translation_changed

Transform Class Reference
[Standard Node Types]

Public Member Functions

Public Attributes

Detailed Description

6.71 Transform

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

Transform Class Reference [Standard Node Types]

Public Member Functions

Public Attributes

Detailed Description

6.71 Transform

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

Transform Class Reference
[Standard Node Types]