SoSpotLightDragger is a composite dragger. It is shaped like a beam of light emanating from a sun-like ball. An arrow runs along the axis of the beam and extends past the end of the beam.

When you click and drag the beam, it opens and closes with an umbrella-like motion. The angle between the center and edge of the beam is stored in the angle field of this dragger; setting the angle field causes the beam to widen or narrow in response. The spotlight dragger does not use a standard dragger class to execute this motion. More details are given later in this section.

Dragging the arrow rotates it around the sun, and the beam moves with it. The arrow is an SoRotateSphericalDragger that controls the rotation field. See the reference page for SoDirectionalLightDragger, which works the same way, for details.

The sun-shape can be dragged to translate all three pieces together through 3-space. Its movement controls the translation field and works exactly as described in the reference pages for SoDirectionalLightDragger and SoPointLightDragger (which goes into more detail).

Remember: This is not a light source! It just looks like one. If you want to move a light with this dragger, you can do the following:

• Use an SoSpotLightManip, which is subclassed from SoLight. It creates an SoSpotLightDragger and uses it as the interface to change the location , direction , and cutOffAngle of its light source (see the SoSpotLightManip reference page). The manip also edits the material part of this dragger to match the color of light the manip is producing.

• Connect the angle field of this dragger to the cutOffAngle field of an SoSpotLight with a field-to-field connection.

See the SoPointLightDragger and SoDirectionalLightDragger reference pages for other ways to control light parameters with the rotation and translation fields.

This class creates its own projector and handles mouse events to do its own dragging of the beam angle. When the mouse picks a point on the beam, that point is dragged in a circle just like in an SoRotateDiscDragger, but the plane of the disc is re-defined every time a drag is initiated. Imagine placing the metal tip of a compass at the apex of the cone and the pencil tip at the picked point. If you swing an arc through the central axis of the cone, you will be drawing the arc used to drag the beam open and closed.

The beam is opened and closed not by rotating, but by scaling. The dragger scales the beam-cone so that the height and radius change to move the picked point along the circle. Then the angle field is calculated from the height and radius.

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

See SoDragger for more information about using and customizing draggers, including code examples, using draggers in an immersive VR environment and using WYSIWYG draggers.

FILE FORMAT/DEFAULT

SpotLightDragger {

renderCaching	AUTO
boundingBoxCaching	AUTO
renderCulling	AUTO
pickCulling	AUTO
isActive	false
rotation	0 0 1 0
translation	0 0 0
angle	1
callbackList	NULL
material	<spotLightOverallMaterial resource>
translator	DragPointDragger { }
rotator	RotateSphericalDragger { }
beamPlacement	<spotLightBeamPlacement resource>
beamScale	Scale {
	scaleFactor 0.841471 0.841471 0.540302
	}
beam	<spotLightBeam resource>
beamActive	<spotLightBeamActive resource>
rotator.rotator	<spotLightRotatorRotator resource>
rotator.rotatorActive	<spotLightRotatorRotatorActive resource>
rotator.feedback	<spotLightRotatorFeedback resource>
rotator.feedbackActive	<spotLightRotatorFeedbackActive resource>
translator.yzTranslator.translator	<spotLightTranslatorPlaneTranslator resource>
translator.xzTranslator.translator	<spotLightTranslatorPlaneTranslator resource>
translator.xyTranslator.translator	<spotLightTranslatorPlaneTranslator resource>
translator.yzTranslator.translatorActive	<spotLightTranslatorPlaneTranslatorActive resource>
translator.xzTranslator.translatorActive	<spotLightTranslatorPlaneTranslatorActive resource>
translator.xyTranslator.translatorActive	<spotLightTranslatorPlaneTranslatorActive resource>
translator.xTranslator.translator	<spotLightTranslatorLineTranslator resource>
translator.yTranslator.translator	<spotLightTranslatorLineTranslator resource>
translator.zTranslator.translator	<spotLightTranslatorLineTranslator resource>
translator.xTranslator.translatorActive	<spotLightTranslatorLineTranslatorActive resource>
translator.yTranslator.translatorActive	<spotLightTranslatorLineTranslatorActive resource>
translator.zTranslator.translatorActive	<spotLightTranslatorLineTranslatorActive resource>

}

DRAGGER RESOURCES

Resource:	spotLightBeam
Part:	beam
Appearance:	wireframe cone with no SoMaterial node
Description:	picking this initiates dragging of the beam angle. The beam inherits colors from the material part, just like the stationary version of the sun shape.
Resource:	spotLightBeamActive
Part:	beamActive
Appearance:	yellow wireframe cone
Description:	displayed during dragging of the beam angle.
Resource:	spotLightBeamPlacement
Part:	beamPlacement
Appearance:	translation of (0,0,-1)
Description:	This translation node moves the beam parts relative to the rest of the dragger. In this case, moving by (0,0,-1) slides the cone outward along rotator part toward its arrowhead. The distance chosen places the apex of the cone on the surface of the sun shape.
Resource:	spotLightRotatorRotator
Part:	rotator.rotator
Appearance:	white arrow that goes through the sun
Description:	picking this begins rotation of the arrow about the sun-shape
Resource:	spotLightRotatorRotatorActive
Part:	rotator.rotatorActive
Appearance:	yellow arrow that goes through the sun
Description:	displayed while the arrow is being rotated
Resource:	spotLightRotatorFeedback
Part:	rotator.feedback
Appearance:	empty Separator
Description:	this disables display of the axes that a rotateSpherical dragger uses by default
Resource:	spotLightRotatorFeedbackActive
Part:	rotator.feedbackActive
Appearance:	empty Separator
Description:	this disables display of the axes that a rotateSpherical dragger uses by default
Resource:	spotLightOverallMaterial
Part:	material
Appearance:	white. half strength emissive, half strength diffuse
Description:	sets material for the sun shape when stationary. Resource for the moving sun, spotLightTranslatorPlaneTranslatorActive, contains a yellow material for highlighting.
Resource:	spotLightTranslatorPlaneTranslator
Parts:	translator.yzTranslator.translator<BR> translator.xzTranslator.translator<BR> translator.xyTranslator.translator
Appearance:	sun shape with no material
Description:	picking these parts initiates dragging by the yz, xz, and xy planar draggers respectively.
Resource:	spotLightTranslatorPlaneTranslatorActive
Parts:	translator.yzTranslator.translatorActive<BR> translator.xzTranslator.translatorActive<BR> translator.xyTranslator.translatorActive
Appearance:	yellow sun shape
Description:	shown during planar dragging in the yz, xz, and xy planes respectively.
Resource:	spotLightTranslatorLineTranslator
Parts:	translator.xTranslator.translator<BR> translator.yTranslator.translator<BR> translator.zTranslator.translator
Appearance:	white cylinder
Description:	picking these parts initiates dragging in the x, y, and z linear draggers respectively.
Resource:	spotLightTranslatorLineTranslatorActive
Parts:	translator.xTranslator.translatorActive<BR> translator.yTranslator.translatorActive<BR> translator.zTranslator.translatorActive
Appearance:	yellow cylinder
Description:	shown during linear dragging in the x, y, and z directions respectively.

CATALOG PARTS

All Parts

Part Name	Part Type	Default Type	NULL Default
callbackList	NodeKitListPart		yes
material	Material		yes
translator	DragPointDragger		yes
rotator	RotateSphericalDragger		yes
beamPlacement	Translation		yes
beamScale	Scale		yes
beam	Separator		yes
beamActive	Separator		yes

Extra Information for List Parts from Above Table

Part Name	Container Type	Possible Types
callbackList	Separator	Callback, EventCallback

Reference