class SG_EXPORT osg::Transform

A Transform is a group node for which all children are transformed by a 4x4 matrix.

Inheritance:

Public Methods

Transform()

Transform(const Transform&, const CopyOp& copyop=CopyOp::SHALLOW_COPY)

Copy constructor using CopyOp to manage deep vs shallow copy

META_Node(osg, Transform)

void setReferenceFrame(ReferenceFrame rf)

Set the transform's ReferenceFrame, either to be relative to its parent reference frame, or relative to an absolute coordinate frame.

const ReferenceFrame getReferenceFrame() const

void setComputeTransformCallback(ComputeTransformCallback* ctc)

Set the ComputerTransfromCallback which allows users to attach custom computation of the local transformation as seen by cull traversers and the like.

ComputeTransformCallback* getComputeTransformCallback()

Get the non const ComputerTransfromCallback

const ComputeTransformCallback* getComputeTransformCallback() const

Get the const ComputerTransfromCallback

inline const bool getLocalToWorldMatrix(Matrix& matrix, NodeVisitor* nv) const

Get the transformation matrix which moves from local coords to world coords.

inline const bool getWorldToLocalMatrix(Matrix& matrix, NodeVisitor* nv) const

Get the transformation matrix which moves from world coords to local coords.

virtual const bool computeLocalToWorldMatrix(Matrix& matrix, NodeVisitor*) const

virtual const bool computeWorldToLocalMatrix(Matrix& matrix, NodeVisitor*) const

Public Members

enum ReferenceFrame

struct ComputeTransformCallback: public osg::Referenced

Callback attached to an Transform to specify how to compute the modelview transformation for the transform below the Transform node.

Protected Fields

ref_ptr<ComputeTransformCallback> _computeTransformCallback

ReferenceFrame _referenceFrame

Protected Methods

virtual ~Transform()

virtual const bool computeBound() const

Overrides Group's computeBound.

Inherited from Group:

Public Methods

virtual void traverse(NodeVisitor& nv)

virtual bool addChild( Node* child )

virtual bool removeChild( Node* child )

virtual bool replaceChild( Node* origChild, Node* newChild )

inline const unsigned int getNumChildren() const

inline Node* getChild( const unsigned int i )

inline const Node* getChild( const unsigned int i ) const

inline bool containsNode( const Node* node ) const

inline ChildList::iterator findNode( const Node* node )

inline ChildList::const_iterator findNode( const Node* node ) const

Protected Fields

ChildList _children

Documentation

A Transform is a group node for which all children are transformed by a 4x4 matrix. It is often used for positioning objects within a scene, producing trackball functionality or for animation.

Transform itself does not provide set/get functions, only the interface for defining what the 4x4 transformation is. Subclasses, such as MatrixTransform and PositionAttitudeTransform support the use of an osg::Matrix or a osg::Vec3/osg::Quat resprectively. The Transform node can be customized via the ComputeTransfromCallback which can be attached to the node. This might be used to convert from internal representations of the transformation into generic osg::Matrix objects which are used during scene grpah traversal, such as CullTraversal and IntersectionTraversal.

Note: if the transformation matrix scales the subgraph then the normals of the underlying geometry will need to be renormalized to be unit vectors once more. This can be done transparently through OpenGL's use of either GL_NORMALIZE and GL_SCALE_NORMALIZE modes. For further background reading see the glNormalize documentation in the OpenGL Reference Guide (the blue book). To enable it in the OSG, you simply need to attach a local osg::StateSet to the osg::Transform, and set the appropriate mode to ON via stateset->setMode(GL_NORMALIZE, osg::StateAttribute::ON);

Transform()

Transform(const Transform&, const CopyOp& copyop=CopyOp::SHALLOW_COPY)

Copy constructor using CopyOp to manage deep vs shallow copy

META_Node(osg, Transform)

enum ReferenceFrame

RELATIVE_TO_PARENTS

RELATIVE_TO_ABSOLUTE

void setReferenceFrame(ReferenceFrame rf)

Set the transform's ReferenceFrame, either to be relative to its parent reference frame, or relative to an absolute coordinate frame. RELATIVE_TO_PARENTS is the default. Note: setting the ReferenceFrame to be RELATIVE_TO_ABSOLUTE will also set the CullingActive flag on the transform, and hence all of its parents, to false, thereby disabling culling of it and all its parents. This is neccessary to prevent inappropriate culling, but may impact cull times if the absolute transform is deep in the scene graph. It is therefore recommend to only use absolute Transforms at the top of the scene, for such things as headlight LightSources or Heads up displays.

const ReferenceFrame getReferenceFrame() const

struct ComputeTransformCallback: public osg::Referenced

Callback attached to an Transform to specify how to compute the modelview transformation for the transform below the Transform node.

virtual const bool computeLocalToWorldMatrix(Matrix& matrix, const Transform* transform, NodeVisitor* nv) const = 0

Get the transformation matrix which moves from local coords to world coords

virtual const bool computeWorldToLocalMatrix(Matrix& matrix, const Transform* transform, NodeVisitor* nv) const = 0

Get the transformation matrix which moves from world coords to local coords

void setComputeTransformCallback(ComputeTransformCallback* ctc)

Set the ComputerTransfromCallback which allows users to attach custom computation of the local transformation as seen by cull traversers and the like.

ComputeTransformCallback* getComputeTransformCallback()

Get the non const ComputerTransfromCallback

const ComputeTransformCallback* getComputeTransformCallback() const

Get the const ComputerTransfromCallback

inline const bool getLocalToWorldMatrix(Matrix& matrix, NodeVisitor* nv) const

Get the transformation matrix which moves from local coords to world coords. Returns true if the Matrix passed in has been updated.

inline const bool getWorldToLocalMatrix(Matrix& matrix, NodeVisitor* nv) const

Get the transformation matrix which moves from world coords to local coords. Return true if the Matrix passed in has been updated.

virtual const bool computeLocalToWorldMatrix(Matrix& matrix, NodeVisitor*) const

virtual const bool computeWorldToLocalMatrix(Matrix& matrix, NodeVisitor*) const

virtual ~Transform()

virtual const bool computeBound() const

Overrides Group's computeBound. There is no need to override in subclasses from osg::Transform since this computeBound() uses the underlying matrix (calling computeMatrix if required.)

ref_ptr<ComputeTransformCallback> _computeTransformCallback

ReferenceFrame _referenceFrame

Direct child classes:

PositionAttitudeTransform
MatrixTransform
DOFTransform

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