javax.media.j3d
Class TransformGroup

java.lang.Object
  |
  +--javax.media.j3d.SceneGraphObject
        |
        +--javax.media.j3d.Node
              |
              +--javax.media.j3d.Group
                    |
                    +--javax.media.j3d.TransformGroup

public class TransformGroup

extends Group

Group node that contains a transform. The TransformGroup node specifies a single spatial transformation, via a Transform3D object, that can position, orient, and scale all of its children.

The specified transformation must be affine. Further, if the TransformGroup node is used as an ancestor of a ViewPlatform node in the scene graph, the transformation must be congruent-only rotations, translations, and uniform scales are allowed in a direct path from a Locale to a ViewPlatform node.

Note: Even though arbitrary affine transformations are allowed, better performance will result if all matrices within a branch graph are congruent, containing only rotations translation, and uniform scale.

The effects of transformations in the scene graph are cumulative. The concatenation of the transformations of each TransformGroup in a direct path from the Locale to a Leaf node defines a composite model transformation (CMT) that takes points in that Leaf node's local coordinates and transforms them into Virtual World (Vworld) coordinates. This composite transformation is used to transform points, normals, and distances into Vworld coordinates. Points are transformed by the CMT. Normals are transformed by the inverse-transpose of the CMT. Distances are transformed by the scale of the CMT. In the case of a transformation containing a nonuniform scale or shear, the maximum scale value in any direction is used. This ensures, for example, that a transformed bounding sphere, which is specified as a point and a radius, continues to enclose all objects that are also transformed using a nonuniform scale.

Field Summary

static int	ALLOW_TRANSFORM_READ Specifies that the node allows access to its object's transform information.
static int	ALLOW_TRANSFORM_WRITE Specifies that the node allows writing its object's transform information.

Fields inherited from class javax.media.j3d.Group

ALLOW_CHILDREN_EXTEND, ALLOW_CHILDREN_READ, ALLOW_CHILDREN_WRITE, ALLOW_COLLISION_BOUNDS_READ, ALLOW_COLLISION_BOUNDS_WRITE

Fields inherited from class javax.media.j3d.Node

ALLOW_AUTO_COMPUTE_BOUNDS_READ, ALLOW_AUTO_COMPUTE_BOUNDS_WRITE, ALLOW_BOUNDS_READ, ALLOW_BOUNDS_WRITE, ALLOW_COLLIDABLE_READ, ALLOW_COLLIDABLE_WRITE, ALLOW_LOCAL_TO_VWORLD_READ, ALLOW_PICKABLE_READ, ALLOW_PICKABLE_WRITE, ENABLE_COLLISION_REPORTING, ENABLE_PICK_REPORTING

Constructor Summary

TransformGroup()
Constructs and initializes a TransformGroup using an identity transform.

TransformGroup(Transform3D t1)
Constructs and initializes a TransformGroup from the Transform passed.

Method Summary

Node	cloneNode(boolean forceDuplicate) Creates a new instance of the node.
void	getTransform(Transform3D t1) Copies the transform component of this TransformGroup into the passed transform object.
void	setTransform(Transform3D t1) Sets the transform component of this TransformGroup to the value of the passed transform.

Methods inherited from class javax.media.j3d.Group

addChild, getAllChildren, getAlternateCollisionTarget, getChild, getCollisionBounds, insertChild, moveTo, numChildren, removeChild, setAlternateCollisionTarget, setChild, setCollisionBounds

Methods inherited from class javax.media.j3d.Node

cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, duplicateNode, getBounds, getBoundsAutoCompute, getCollidable, getLocalToVworld, getLocalToVworld, getParent, getPickable, setBounds, setBoundsAutoCompute, setCollidable, setPickable

Methods inherited from class javax.media.j3d.SceneGraphObject

clearCapability, duplicateSceneGraphObject, getCapability, getUserData, isCompiled, isLive, setCapability, setUserData, updateNodeReferences

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ALLOW_TRANSFORM_READ

public static final int ALLOW_TRANSFORM_READ

Specifies that the node allows access to its object's transform information.

ALLOW_TRANSFORM_WRITE

public static final int ALLOW_TRANSFORM_WRITE

Specifies that the node allows writing its object's transform information.

Constructor Detail

TransformGroup

public TransformGroup()

Constructs and initializes a TransformGroup using an identity transform.

TransformGroup

public TransformGroup(Transform3D t1)

Constructs and initializes a TransformGroup from the Transform passed.

Parameters:

t1 - the transform3D object

Throws:

BadTransformException - if the transform is not affine.

Method Detail

setTransform

public void setTransform(Transform3D t1)

Sets the transform component of this TransformGroup to the value of the passed transform.

Parameters:

t1 - the transform to be copied

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

BadTransformException - if the transform is not affine.

getTransform

public void getTransform(Transform3D t1)

Copies the transform component of this TransformGroup into the passed transform object.

Parameters:

t1 - the transform object to be copied into

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

cloneNode

public Node cloneNode(boolean forceDuplicate)

Creates a new instance of the node. This routine is called by cloneTree to duplicate the current node.

Overrides:

cloneNode in class Group

Parameters:

forceDuplicate - when set to true, causes the duplicateOnCloneTree flag to be ignored. When false, the value of each node's duplicateOnCloneTree variable determines whether NodeComponent data is duplicated or copied.

See Also:

Node.cloneTree(), Node.cloneNode(boolean), Node.duplicateNode(javax.media.j3d.Node, boolean), NodeComponent.setDuplicateOnCloneTree(boolean)