SoCenterballDragger is a composite dragger. Its shape is a sphere defined by three intersecting circles. Where the circles intersect (at the ends of the x, y and z axes) there are sets of small green crosshairs. Dragging a pair of crosshairs translates the entire centerball within the plane of the crosshairs. The interface of the sphere and circles is just like SoTrackballDragger. Dragging a circle rotates about a constrained axis and dragging the areas between them rotates the sphere freely about the center. An invisible but pickable sphere initiates the free-rotation dragging.

When you drag the crosshairs, the center field is updated; there is no translation field. Dragging other parts of the centerball updates the rotation field. As with all draggers, if you change the fields the dragger moves in response.

The draggers used for the crosshair parts are SoTranslate2Draggers, so pressing the <Shift> key allows you to constrain motion to slide along either the local x axis or y axis of that crosshair. The direction is determined by your initial mouse gesture after pressing the key. Releasing the key removes the constraint.

Remember: This is not an SoTransform! If you want to move other objects with this dragger, you can either:

• Use an SoCenterballManip, which is subclassed from SoTransform. The manipulator creates one of these draggers and uses it as the interface to edit the manipulator's fields. (See the SoCenterballManip reference page.)

• Use field-to-field connections to connect the fields of this dragger to those of any SoTransformation node.

You can change the parts in any instance of this dragger using setPart(). The default part geometries are defined as resources for this SoCenterballDragger class. They are detailed in the Dragger Resources section of the online reference page for this class. You can make your program use different default resources for the parts by copying the file $OIVHOME/data/draggerDefaults/centerballDragger.iv into your own directory, editing the file, and then setting the environment variable SO_DRAGGER_DIR to be a path to that directory.

This dragger has both a default and a WYSIWYG version:

Default Dragger	WYSIWYG Dragger

FILE FORMAT/DEFAULT

CenterballDragger {

renderCaching	AUTO
boundingBoxCaching	AUTO
renderCulling	AUTO
pickCulling	AUTO
isActive	false
rotation	0 0 1 0
center	0 0 0
callbackList	NULL
translateToCenter	MatrixTransform {
	matrix
	1 0 0 0
	0 1 0 0
	0 0 1 0
	0 0 0 1
	}
surroundScale	NULL
antiSquish	AntiSquish {
	sizing LONGEST_DIAGONAL
	}
lightModel	LightModel {
	model PHONG
	}
XAxis	<centerballXAxis resource>
YAxis	<centerballYAxis resource>
ZAxis	<centerballZAxis resource>
rotator	RotateSphericalDragger {
	}
YRotator	RotateCylindricalDragger {
	}
ZCenterChanger	Translate2Dragger {
	}
ZRotator	RotateCylindricalDragger {
	}
YCenterChanger	Translate2Dragger {
	}
XCenterChanger	Translate2Dragger {
	}
XRotator	RotateCylindricalDragger {
	}
rotator.rotator	<centerballRotator resource>
rotator.rotatorActive	<centerballRotatorActive resource>
XRotator.rotator	<centerballStripe resource>
YRotator.rotator	<centerballStripe resource>
ZRotator.rotator	<centerballStripe resource>
XRotator.rotatorActive	<centerballStripeActive resource>
YRotator.rotatorActive	<centerballStripeActive resource>
ZRotator.rotatorActive	<centerballStripeActive resource>
XCenterChanger.translator	<centerballCenterChanger resource>
YCenterChanger.translator	<centerballCenterChanger resource>
ZCenterChanger.translator	<centerballCenterChanger resource>
XCenterChanger.translatorActive	<centerballCenterChangerActive resource>
YCenterChanger.translatorActive	<centerballCenterChangerActive resource>
ZCenterChanger.translatorActive	<centerballCenterChangerActive resource>
XCenterChanger.xAxisFeedback	<centerballCenterXAxisFeedback resource>
YCenterChanger.xAxisFeedback	<centerballCenterXAxisFeedback resource>
ZCenterChanger.xAxisFeedback	<centerballCenterXAxisFeedback resource>
XCenterChanger.yAxisFeedback	<centerballCenterYAxisFeedback resource>
YCenterChanger.yAxisFeedback	<centerballCenterYAxisFeedback resource>
ZCenterChanger.yAxisFeedback	<centerballCenterYAxisFeedback resource>

}

<H3>DRAGGER RESOURCES</H3>
  <TABLE border=1 cellspacing=0 cellpadding=5>
     <TR><TD valign=_top> Resource:       <TD valign=_top> <B> centerballRotator </B>
     <TR><TD valign=_top> Part:           <TD valign=_top> rotator.rotator
     <TR><TD valign=_top> Appearance:     <TD valign=_top> Invisible but pickable sphere
     <TR><TD valign=_top> Description:    <TD valign=_top> When picked, initiates free rotation about the center point. Slightly smaller
                        radius than the stripes, so you must pick between the stripes to use it.

     <TR><TD valign=_top> Resource:       <TD valign=_top> <B> centerballRotatorActive </B>
     <TR><TD valign=_top> Part:           <TD valign=_top> rotator.rotatorActive
     <TR><TD valign=_top> Appearance:     <TD valign=_top> Invisible sphere
     <TR><TD valign=_top> Description:    <TD valign=_top> Displayed during unconstrained 3D rotation instead of centerballRotator.

     <TR><TD valign=_top> Resource:       <TD valign=_top> <B> centerballStripe </B>
     <TR><TD valign=_top> Parts:          <TD valign=_top> XRotator.rotator<BR>
                            YRotator.rotator<BR>
                            ZRotator.rotator 
     <TR><TD valign=_top> Appearance:     <TD valign=_top> White circle aligned with rotation axis.
     <TR><TD valign=_top> Description:    <TD valign=_top> When picked, initiates constrained rotation. Each rotator rotates locally about
                        its Y axis. The centerball contains private transform parts that orient the
                        draggers along three different axes.

     <TR><TD valign=_top> Resource:       <TD valign=_top> <B> centerballStripeActive </B>
     <TR><TD valign=_top> Parts:          <TD valign=_top> XRotator.rotatorActive<BR>
                            YRotator.rotatorActive<BR>
                            ZRotator.rotatorActive 
     <TR><TD valign=_top> Appearance:     <TD valign=_top> White circle aligned with the rotation axis.
     <TR><TD valign=_top> Description:    <TD valign=_top> Displayed during constrained rotation instead of the rotator part. The
                        centerball orients the draggers along three different axes.

     <TR><TD valign=_top> Resource:       <TD valign=_top> <B> centerballCenterChanger </B>
     <TR><TD valign=_top> Parts:          <TD valign=_top> XCenterChanger.translator<BR>
                            YCenterChanger.translator<BR>
                            ZCenterChanger.translator 
     <TR><TD valign=_top> Appearance:     <TD valign=_top> Two sets of small green crosshairs, one located at each intersection of

Description:

When picked, initiates 2D translation of ball through space. Edits the center field, which becomes center for subsequent rotations. Each translator works locally in its X-Y plane. The centerball containsprivate transform parts that place the draggers along three different axes.

Resource:

centerballCenterChangerActive

Parts:

XCenterChanger.translatorActive<BR> YCenterChanger.translatorActive<BR> ZCenterChanger.translatorActive

Appearance:

Yellow version of centerballCenterChanger.

Description:

Displayed during 2D translation instead of regular translator part. The centerball places the draggers along three different axes.

Resource:

centerballCenterXAxisFeedback

Parts:

XCenterChanger.xAxisFeedback<BR> YCenterChanger.xAxisFeedback<BR> ZCenterChanger.xAxisFeedback

Appearance:

Double-headed purple arrows, one located at each intersection of axis and ball. Located atop X axis of crosshair.

Description:

Only shown if dragger is moving and the axis is a permitted direction of motion. When pressing <shift>, motion is constrained, and this is displayed only if the primary motion is in the X direction of the child dragger's local space. The centerball places the draggers along three different axes; so not all of these parts aligns with the X axis in centerball space.

Resource:

centerballCenterYAxisFeedback

Parts:

XCenterChanger.yAxisFeedback<BR> YCenterChanger.yAxisFeedback<BR> ZCenterChanger.yAxisFeedback

Appearance:

Double-headed purple arrows, one located at each intersection of axis and ball. Located atop Y axis of crosshair.

Description:

Only shown if dragger is moving and the axis is a permitted direction of motion. When pressing <shift>, motion is constrained, and this is displayed only if the primary motion is in the Y direction of the child dragger's local space. The centerball places the draggers along three different axes; so not all of these parts aligns with the Y axis in centerball space.

Resource:

centerballXAxis

Part:

XAxis

Appearance:

Thin yellow line connecting left and right crosshairs.

Description:

Feedback shown alone during rotation about X axis; displayed with centerballYAxis and centerballZAxis while center is dragged.

Resource:

centerballYAxis

Part:

YAxis

Appearance:

Thin yellow line connecting lower and upper crosshairs.

Description:

Feedback shown alone during rotation about Y axis; displayed with centerballXAxis and centerballZAxis while center is dragged.

Resource:

centerballZAxis

Part:

ZAxis

Appearance:

Thin yellow line connecting near and far crosshairs.

Description:

Feedback shown alone during rotation about Z axis; displayed with centerballXAxis and centerballYAxis while center is dragged.

CATALOG PARTS

All Parts

Part Name	Part Type	Default Type	NULL Default
callbackList	NodeKitListPart		yes
translateToCenter	MatrixTransform		yes
surroundScale	SurroundScale		yes
antiSquish	AntiSquish		no
lightModel	LightModel		yes
XAxis	Separator		yes
YAxis	Separator		yes
ZAxis	Separator		yes
rotator	RotateSphericalDragger		yes
YRotator	RotateCylindricalDragger		yes
ZCenterChanger	Translate2Dragger		yes
ZRotator	RotateCylindricalDragger		yes
YCenterChanger	Translate2Dragger		yes
XCenterChanger	Translate2Dragger		yes
XRotator	RotateCylindricalDragger		yes

Extra Information for List Parts from Above Table

Part Name	Container Type	Possible Types
callbackList	Separator	Callback, EventCallback

Reference