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# SoVRMLTransform Class Reference
[VRML97 classes]

The SoVRMLTransform class is a grouping node that defines a transformation for its children. More...

`#include <Inventor/VRMLnodes/SoVRMLTransform.h>`

Inheritance diagram for SoVRMLTransform:

List of all members.

## Public Methods
| SoVRMLTransform (void)
| SoVRMLTransform (int children)
void | pointAt (const SbVec3f &from, const SbVec3f &to)
void | getScaleSpaceMatrix (SbMatrix &matrix, SbMatrix &inverse) const
void | getRotationSpaceMatrix (SbMatrix &matrix, SbMatrix &inverse) const
void | getTranslationSpaceMatrix (SbMatrix &matrix, SbMatrix &inverse) const
void | multLeft (const SbMatrix &matrix)
void | multRight (const SbMatrix &matrix)
void | combineLeft (SoVRMLTransform *leftnode)
void | combineRight (SoVRMLTransform *rightnode)
void | setMatrix (const SbMatrix &matrix)
void | recenter (const SbVec3f &newcenter)
virtual void | doAction (SoAction *action)
virtual void | callback (SoCallbackAction *action)
virtual void | getBoundingBox (SoGetBoundingBoxAction *action)
virtual void | getMatrix (SoGetMatrixAction *action)
virtual void | rayPick (SoRayPickAction *action)
virtual void | getPrimitiveCount (SoGetPrimitiveCountAction *action)
virtual void | audioRender (SoAudioRenderAction *action)
virtual void | GLRenderBelowPath (SoGLRenderAction *action)
virtual void | GLRenderInPath (SoGLRenderAction *action)
virtual void | notify (SoNotList *list)
## Static Public Methods
void | initClass (void)
## Public Attributes
SoSFVec3f | translation
SoSFRotation | rotation
SoSFVec3f | scale
SoSFRotation | scaleOrientation
SoSFVec3f | center
## Protected Methods
virtual | ~SoVRMLTransform ()

## Detailed Description

The SoVRMLTransform class is a grouping node that defines a transformation for its children.

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:

      Transform {
        eventIn      MFNode      addChildren
        eventIn      MFNode      removeChildren
        exposedField SFVec3f     center           0 0 0    # (-inf,inf)
        exposedField MFNode      children         []
        exposedField SFRotation  rotation         0 0 1 0  # [-1,1],(-inf,inf)
        exposedField SFVec3f     scale            1 1 1    # (0,inf)
        exposedField SFRotation  scaleOrientation 0 0 1 0  # [-1,1],(-inf,inf)
        exposedField SFVec3f     translation      0 0 0    # (-inf,inf)
        field        SFVec3f     bboxCenter       0 0 0    # (-inf,inf)
        field        SFVec3f     bboxSize         -1 -1 -1 # (0,inf) or -1,-1,-1
      }

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 (<http://www.web3d.org/technicalinfo/specifications/vrml97/part1/concepts.html#4.4.4>), and 4.4.5, Standard units and coordinate system (<http://www.web3d.org/technicalinfo/specifications/vrml97/part1/concepts.html#4.4.5>), for a description of coordinate systems and transformations.

4.6.5, Grouping and children nodes (<http://www.web3d.org/technicalinfo/specifications/vrml97/part1/concepts.html#4.6.5>), 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 (<http://www.web3d.org/technicalinfo/specifications/vrml97/part1/concepts.html#4.6.4>).

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

SoVRMLTransform::SoVRMLTransform | ( | void |  | ) |

| Constructor.

SoVRMLTransform::SoVRMLTransform | ( | int | numchildren | ) |

| Constructor. numchildren is the expected number of children.

SoVRMLTransform::~SoVRMLTransform | ( |  | ) | `[protected, virtual]`

| Destructor

## Member Function Documentation

void SoVRMLTransform::initClass | ( | void |  | ) | `[static]`

| Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system. Reimplemented from SoVRMLGroup.

void SoVRMLTransform::pointAt | ( | const SbVec3f & | from,
|  | const SbVec3f & | to
| ) |

| Sets the transformation to translate to frompoint, with a rotation so that the (0,0,-1) vector is rotated into the vector from frompoint to topoint.

void SoVRMLTransform::getScaleSpaceMatrix | ( | SbMatrix & | matrix,
|  | SbMatrix & | inverse
| ) | const

| Calculates the matrices to/from scale space.

void SoVRMLTransform::getRotationSpaceMatrix | ( | SbMatrix & | matrix,
|  | SbMatrix & | inverse
| ) | const

| Calculates the matrices to/from rotation space.

void SoVRMLTransform::getTranslationSpaceMatrix | ( | SbMatrix & | matrix,
|  | SbMatrix & | inverse
| ) | const

| Calculates the matrices to/from translation space.

void SoVRMLTransform::multLeft | ( | const SbMatrix & | matrix | ) |

| Premultiplies this transformation by mat.

void SoVRMLTransform::multRight | ( | const SbMatrix & | matrix | ) |

| Postmultiplies this transformation by mat.

void SoVRMLTransform::combineLeft | ( | SoVRMLTransform * | leftnode | ) |

| Premultiplies this transformation by the transformation in leftnode.

void SoVRMLTransform::combineRight | ( | SoVRMLTransform * | rightnode | ) |

| Postmultiplies this transformation by the transformation in rightnode.

void SoVRMLTransform::setMatrix | ( | const SbMatrix & | matrix | ) |

| Sets the fields to create a transformation equal to mat.

void SoVRMLTransform::recenter | ( | const SbVec3f & | newcenter | ) |

| Sets the center field to newcenter. This might affect one or more of the other fields.

void SoVRMLTransform::doAction | ( | SoAction * | action | ) | `[virtual]`

| This function performs the typical operation of a node for any action. Reimplemented from SoVRMLGroup.

void SoVRMLTransform::callback | ( | SoCallbackAction * | action | ) | `[virtual]`

| Action method for SoCallbackAction. Simply updates the state according to how the node behaves for the render action, so the application programmer can use the SoCallbackAction for extracting information about the scene graph. Reimplemented from SoVRMLGroup.

void SoVRMLTransform::getBoundingBox | ( | SoGetBoundingBoxAction * | action | ) | `[virtual]`

| Action method for the SoGetBoundingBoxAction. Calculates bounding box and center coordinates for node and modifies the values of the action to encompass the bounding box for this node and to shift the center point for the scene more towards the one for this node. Nodes influencing how geometry nodes calculates their bounding box also overrides this method to change the relevant state variables. Reimplemented from SoVRMLGroup.

void SoVRMLTransform::getMatrix | ( | SoGetMatrixAction * | action | ) | `[virtual]`

| Action method for SoGetMatrixAction. Updates action by accumulating with the transformation matrix of this node (if any). Reimplemented from SoVRMLGroup.

void SoVRMLTransform::rayPick | ( | SoRayPickAction * | action | ) | `[virtual]`

| Action method for SoRayPickAction. Checks the ray specification of the action and tests for intersection with the data of the node. Nodes influencing relevant state variables for how picking is done also overrides this method. Reimplemented from SoVRMLGroup.

void SoVRMLTransform::getPrimitiveCount | ( | SoGetPrimitiveCountAction * | action | ) | `[virtual]`

| Action method for the SoGetPrimitiveCountAction. Calculates the number of triangle, line segment and point primitives for the node and adds these to the counters of the action. Nodes influencing how geometry nodes calculates their primitive count also overrides this method to change the relevant state variables. Reimplemented from SoVRMLGroup.

void SoVRMLTransform::audioRender | ( | SoAudioRenderAction * | action | ) | `[virtual]`

| Action method for SoAudioRenderAction. Does common processing for SoAudioRenderAction action instances. Reimplemented from SoVRMLGroup.

void SoVRMLTransform::GLRenderBelowPath | ( | SoGLRenderAction * | action | ) | `[virtual]`

| Implements the SoAction::BELOW_PATH traversal method for the rendering action. Reimplemented from SoVRMLGroup.

void SoVRMLTransform::GLRenderInPath | ( | SoGLRenderAction * | action | ) | `[virtual]`

| Implements the SoAction::IN_PATH traversal method for the rendering action. Reimplemented from SoVRMLGroup.

void SoVRMLTransform::notify | ( | SoNotList * | list | ) | `[virtual]`

| Notifies all auditors for this instance when changes are made. Reimplemented from SoVRMLGroup.

## Member Data Documentation

SoSFVec3f SoVRMLTransform::translation

| The translation vector. Default value is (0, 0, 0).

SoSFRotation SoVRMLTransform::rotation

| The rotation around the center point. Default value is null-rotation.

SoSFVec3f SoVRMLTransform::scale

| The scale vector about the center point. Default value is (1, 1, 1).

SoSFRotation SoVRMLTransform::scaleOrientation

| The scale orientation. Default value is a null-rotation.

SoSFVec3f SoVRMLTransform::center

| The center point. Default value is (0, 0, 0).

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

- SoVRMLTransform.h
- Transform.cpp