SoSpotLightManip is the base class for all SoSpotLight nodes that have a built-in 3D user interface (this is the only such class provided with the Inventor toolkit). Since it is derived from SoSpotLight, any changes to its fields result in a change of lighting for nodes that follow it in the scene graph. In this case, the interface edits the location, direction, and cutOffAngle fields. Also, the color of the manipulator's geometry will reflect the color of the light (but you can not edit the color using this manipulator).

Typically, you will want to replace a regular SoSpotLight with an SoSpotLightManip (as when the user selects a light to be edited), or vice versa (as when the user is done moving the light and the interface should go away). Use the replaceNode() method to insert a manipulator into a scene graph, and the replaceManip() method to remove it when done.

The SoSpotLightManip utilizes an SoSpotLightDragger to provide a 3D interface. However, the manipulator differs from the dragger; it lights other objects in the scene because, as an SoSpotLight, it alters the state. The fields values and movement of the dragger, on the other hand, affect only the dragger itself. To find out more about how the interface works and what each part will do, see the reference page for SoSpotLightDragger. The interfaces of the dragger and the manipulator are identical.

The SoSpotLightManip utilizes its dragger by adding it as a hidden child. When an action is applied to the manipulator, such as rendering or handling events, the manipulator first traverses the dragger, and then the manipulator adds its lighting parameters to the state. When you click-drag-release over the manipulator, it passes these events down to the dragger, which moves as a result ("I can't help it, I'm a dragger!").

The manipulator maintains consistency between the fields of the dragger and its own fields. Let's say you use the mouse to widen the cone of the dragger. Callbacks insure that the cutOffAngle field of the manipulator will change by the same amount, thus changing the lighting of nodes which follow in the scene graph. Similarly, if you set the cutOffAngle field of the SoSpotLightManip, the manipulator will widen the beam of the dragger accordingly.

Because the dragger is a hidden child, you can see the dragger on screen and interact with it, but the dragger does not show up when you write the manipulator to file. Also, any SoPath will end at the manipulator. (See the Actions section of this reference page for a complete description of when the dragger is traversed).

If you want to get a pointer to the dragger you can get it from the manipulator using the getDragger() method. You will need to do this if you want to change the geometry of a manipulator, since the geometry actually belongs to the dragger.