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SceneOrbiter Class
Tool class for building a basic interactive OpenInventor application with mode-less scene "orbiter" viewing behavior.

The SceneOrbiter is an extension of the SceneInteractor node that provides camera and headlight manipulations like panning, zooming and orbiting similar to the classic Open Inventor "Examiner" viewer classes (e.g. SoWinExaminerViewer) and the SceneExaminer (in Orbit navigation mode).

Preview Feature: this class is fully supported and can be used in Open Inventor applications. Being tagged as a Preview Feature just means that the implementation is still subject to API changes and adjustments based on feedback from early adopters. Please be also aware that source compatibility might be broken regardless of the Open Inventor compatibility changes policy due to our commitment to bring needed changes to be sure the specifications of this Preview Feature match the expectations of our customers.

Inheritance Hierarchy

Namespace: OIV.Inventor.ViewerComponents.Nodes
Assembly: OIV.Inventor.ViewerComponents (in OIV.Inventor.ViewerComponents.dll) Version: 2023.1.3.0.Release.5fd1c1ad27c99c06f73891d4218ee7122fbde35a
Syntax
public sealed class SceneOrbiter : SceneInteractor

The SceneOrbiter type exposes the following members.

Constructors
  NameDescription
Public methodSceneOrbiter
Default constructor.
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Methods
  NameDescription
Public methodAddChild

Adds a child as last one in group.

(Inherited from SoGroup.)
Public methodAdjustClippingPlanes
Adjust near and far clipping planes to minimize clipping of objects in the scene. This adjustment, based on the bounding box of the scene, ensures that shapes will not be clipped and also that depth buffer precision is maximized. This method should be called before each render traversal.
(Inherited from SceneInteractor.)
Public methodAffectsState

Returns true if a node has an effect on the state during traversal.

(Inherited from SoSeparator.)
Public methodCallback
(Inherited from SoSeparator.)
Public methodClearCacheList
(Inherited from SoSeparator.)
Public methodCopy
Calls Copy(false).
(Inherited from SoNode.)
Public methodCopy(Boolean)

Creates and returns an exact copy of the node.

(Inherited from SoNode.)
Public methodCopyFieldValues(SoFieldContainer)
Calls CopyFieldValues(fc, false).
(Inherited from SoFieldContainer.)
Public methodCopyFieldValues(SoFieldContainer, Boolean)

Copies the contents of fc's fields into this object's fields.

(Inherited from SoFieldContainer.)
Public methodDispose
Releases all resources used by SoDisposable.
(Inherited from SoDisposable.)
Public methodDistribute
(Inherited from SoNode.)
Public methodDoAction
(Inherited from SoSeparator.)
Public methodEnableNotify

Notification at this Field Container is enabled (if flag == true) or disabled (if flag == false).

(Inherited from SoFieldContainer.)
Public methodEquals
Determines whether the specified Object is equal to the current Object.
(Inherited from Object.)
Public methodFieldsAreEqual

Returns true if this object's fields are exactly equal to fc's fields.

(Inherited from SoFieldContainer.)
Public methodFindChild

Finds index of given child within group.

(Inherited from SoGroup.)
Public methodGet

Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string.

(Inherited from SoFieldContainer.)
Public methodGetAllFields

Returns a list of fields, including the eventIn's and eventOut's.

(Inherited from SoFieldContainer.)
Public methodGetAlternateRep

This method is called by actions to allow the node to provide an "alternate representation" when appropriate (typically depending on the action type).

(Inherited from SoNode.)
Public methodGetBoundingBox
(Inherited from SoSeparator.)
Public methodGetChild

Returns pointer the child node with the given index.

(Inherited from SoGroup.)
Public methodGetEventIn

Returns a the eventIn with the given name.

(Inherited from SoFieldContainer.)
Public methodGetEventOut

Returns the eventOut with the given name.

(Inherited from SoFieldContainer.)
Public methodGetField

Returns a the field of this object whose name is fieldName.

(Inherited from SoFieldContainer.)
Public methodGetFieldName

Returns the name of the given field in the fieldName argument.

(Inherited from SoFieldContainer.)
Public methodGetFields

Appends references to all of this object's fields to resultList, and returns the number of fields appended.

(Inherited from SoFieldContainer.)
Public methodGetHashCode
Overrides GetHashCode().
(Inherited from SoNetBase.)
Public methodGetMatrix
(Inherited from SoSeparator.)
Public methodGetName

Returns the name of an instance.

(Inherited from SoBase.)
Public methodGetNumChildren

Returns number of children.

(Inherited from SoGroup.)
Public methodGetPrimitiveCount
(Inherited from SoSeparator.)
Public methodGetRenderEngineMode
This override is mandatory to specify the custom node's render engine mode. If not overridden, a warning message will be displayed.
(Inherited from SceneInteractor.)
Public methodGetRenderUnitID
(Inherited from SoNode.)
Public methodGetStringName (Inherited from SoBase.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodGLRender
(Inherited from SoSeparator.)
Public methodGLRenderBelowPath
(Inherited from SoSeparator.)
Public methodGLRenderInPath
(Inherited from SoSeparator.)
Public methodGLRenderOffPath
(Inherited from SoSeparator.)
Public methodGrabEventsCleanup
(Inherited from SoNode.)
Public methodGrabEventsSetup
(Inherited from SoNode.)
Public methodHandleEvent
(Inherited from SoSeparator.)
Public methodHasDefaultValues

Returns true if all of the object's fields have their default values.

(Inherited from SoFieldContainer.)
Public methodInsertChild

Adds a child so that it becomes the one with the given index.

(Inherited from SoGroup.)
Public methodIsBoundingBoxIgnoring

Used by BoundingBoxAction to known if bounding box computation should be ignored or not.

(Inherited from SoGroup.)
Public methodIsNotifyEnabled

Notification is the process of telling interested objects that this object has changed.

(Inherited from SoFieldContainer.)
Public methodIsOverride

Returns the state of the override flag.

(Inherited from SoNode.)
Public methodIsSynchronizable

Gets the ScaleViz synchronizable state of this object.

(Inherited from SoBase.)
Public methodPick
(Inherited from SoGroup.)
Public methodRayPick
(Inherited from SoSeparator.)
Public methodRemoveAllChildren

Removes all children from group.

(Inherited from SoGroup.)
Public methodRemoveChild(Int32)

Removes child with given index from group.

(Inherited from SoGroup.)
Public methodRemoveChild(SoNode)

Removes first instance of given child from group.

(Inherited from SoGroup.)
Public methodReplaceChild(Int32, SoNode)

Replaces child with given index with new child.

(Inherited from SoGroup.)
Public methodReplaceChild(SoNode, SoNode)

Replaces first instance of given child with new child.

(Inherited from SoGroup.)
Public methodSearch
(Inherited from SoSeparator.)
Public methodSet

Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format.

(Inherited from SoFieldContainer.)
Public methodSetName (Inherited from SoBase.)
Public methodSetOverride

Turns the override flag on or off.

(Inherited from SoNode.)
Public methodSetSynchronizable

Sets this to be a ScaleViz synchronizable object.

(Inherited from SoBase.)
Public methodSetToDefaults

Sets all fields in this object to their default values.

(Inherited from SoFieldContainer.)
Public methodToString
Converts this SoBase structure to a human readable string.
(Inherited from SoBase.)
Public methodTouch

Marks an instance as modified, simulating a change to it.

(Inherited from SoNode.)
Public methodViewAll
Set the camera to view all the scene.
(Inherited from SceneInteractor.)
Public methodViewAxis
Moves the camera to be aligned with the given direction vector while keeping the "up" direction of the camera parallel to the specified up vector.
(Inherited from SceneInteractor.)
Public methodWrite
(Inherited from SoGroup.)
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Properties
  NameDescription
Public propertyboundingBoxCaching
(Inherited from SoSeparator.)
Public propertyboundingBoxIgnoring

Whether to ignore this node during bounding box traversal.

(Inherited from SoGroup.)
Public propertyCamera
Gets the current camera.
(Inherited from SceneInteractor.)
Public propertyCameraInteractor
Gets the current camera interactor.
(Inherited from SceneInteractor.)
Public propertyCameraMode
Gets/sets the camera mode.
(Inherited from SceneInteractor.)
Public propertyConstraintLevel
Gets/sets the constraint level to limit the turntable rotation.
Public propertyfastEditing

Specifies the fast edit mode of the separator node.

(Inherited from SoSeparator.)
Public propertyHeadlightEnabled
Enables/Disables the headlight.
(Inherited from SceneInteractor.)
Public propertyIsDisposable
ISafeDisposable interface implementation.
(Inherited from SoDisposable.)
Public propertypickCulling

Whether to cull during picking traversal.

(Inherited from SoSeparator.)
Public propertyrenderCaching Obsolete.

Whether to cache during rendering traversal.

(Inherited from SoSeparator.)
Public propertyrenderCulling

Whether to cull during rendering traversal.

(Inherited from SoSeparator.)
Public propertyrenderUnitId

Used during the ScaleViz depth compositing process, this field specifies which render unit (OIRU) will render the sub scene graph below this separator.

(Inherited from SoSeparator.)
Public propertyRotationMethod
Gets/sets the scene rotation method. Default is TURNTABLE.
Public propertyUpAxis
Gets/sets the up axis of the scene. Default is Y. Note that the up axis of the viewing cube is synchronized with the up axis of the SceneOrbiter.
Public propertyUserData
Gets or sets the user data to be contained by the field container.
(Inherited from SoFieldContainer.)
Public propertyViewingCube
Gets viewing cube.
Public propertyViewingCubeEnabled
Enables/disables viewing cube. Default is true.
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Remarks

The SceneOrbiter provides a "mode-less" viewer that is very convenient for users. The Examiner viewer and SceneExaminer viewers are always in either viewing mode (mouse events control the camera) or in selection mode (mouse events are sent to the scene graph and objects can be selected). This often requires the user to frequently switch between viewing and selection mode (for example by pressing the ESC key) while interacting with the scene. SceneOrbiter does not have modes. For example, a mouse click without moving the mouse is interpreted as a selection and the event is sent to the scene graph, but a mouse click and "drag" is interpreted as controlling the camera.

The SceneOrbiter provides two different methods to control the rotation of the camera around the scene : trackball and turntable, see SceneOrbiterRotationMethods enum. The trackball method lets the camera move along any circular orbit around the scene and look in the direction of its center.The orbit orientation can change at any time while interpreting a mouse drag.Thus the trackball is known as an unconstrained orbiting mode. The trackball is the unique method used by the historical examiner viewer and by the SceneExaminer. The additional turntable method is a more constrained orbiting mode.It lets the camera move only along vertical orbits such as the earth meridians, and along horizontal circles such as the earth parallels.The vertical orbits and horizontal circles are related to an up axis, that can be changed with UpAxis property. The horizontal circles are centered around this up axis, and the vertical orbits share their south and north pole on this up axis. As the camera cannot move along any other circle, this mode is more constrained compared to the trackball mode. However that gives a more natural navigation experience when viewing scene that has strong vertical and horizontal references.For instance, when orbiting in turntable mode around a scene representing the Eiffel tower, this one looks always vertical on your screen.Compared to the trackball mode, the turntable mode does not need any tedious small mouse move correction to keep the scene well aligned to the borders of the screen.

The 'headlight', an SoDirectionalLight node, is automatically aligned with the camera's view direction. An SoViewingCube node is automatically added to the scene. The viewing cube can be hidden by changing value of the ViewingCubeEnabled property. Note that the up axis of the viewing cube is synchronized with the up axis of the SceneOrbiter. See parent class SceneInteractor for more details about the structure of the internal scene graph.

The SceneOrbiter uses an instance of SoCameraInteractor in order to manipulate the camera in response to OpenInventor events.

Remarks

Notes:

  • Window system integration - The SceneOrbiter needs a component that integrates the Open Inventor 3D rendering window with the native window system. System dependent tasks include creating a window, placing the window in the application's user interface, initializing OpenGL and processing the native event/message loop. System independent support for this is provided by the SoRenderAreaCore class. Example components are provided for WPF.
  • Event handling - The SceneOrbiter needs a component that builds OpenInventor events (SoEvent) from native system events. System independent support for this is provided by the SoEventBuilder class. Example component is provided for WPF, see WpfEventToSoEvent.
  • Library - A basic version of SceneOrbiter is a supported part of the Open Inventor API and prebuilt library is provided.
  • Source code - The basic version of SceneOrbiter is also provided as source code to allow applications to customize and build their own interactive tool class. See $OIVNETHOME/source/OIV.Inventor.Viewercomponents/Nodes/.
  • Scene graph - The application scene graph should be the last child of the SceneOrbiter. The initial application scene graph can be added by simply calling the inherited method AddChild(). But note that if you need to replace the application scene graph, for example loading a new data set, do not call RemoveAllChildren(). That would also remove the SceneOrbiter's camera, headlight and event handler nodes. Add an SoSeparator to the SceneOrbiter to serve as the "scene graph holder", then add and remove the application scene graph from this node.
  • Clip planes - SceneOrbiter automatically adjusts the 'near' and 'far' clipping planes when events modifying the camera are handled. This adjustment, based on the bounding box of the scene, ensures that shapes will not be clipped as the camera orbits and also that depth buffer precision is maximized. Note: Updating clipping planes after a camera move can be insufficient. If the scene graph is modified or if a dragger or a rendered shape is moved, they can disappear or become partially clipped. A classic implementation of a render area must adjust clipping planes before each rendering by calling the provided method AdjustClippingPlanes(SbViewportRegion). See render area's implementations available in $OIVNETHOME/source/OIV.Inventor.Viewercomponents.Wpf folder for examples of AdjustClippingPlanes use.
  • Compatibility with classical viewers - Please note that some interaction behaviors are different from the classic Open Inventor viewer classes (e.g. SoWinExaminerViewer) :
    • Left Mouse + Shift does Zoom in/out.
    • Mouse wheel performs a dolly relative to the cursor position, not the center of the viewport.
    • The classic ESC key behavior is not implemented. (Not necessary because viewing and selection are supported without separate modes.)
    • The classic Alt key behavior is not implemented. This key is reserved for application use.
    • The Right Mouse button does not display a popup menu. This button is reserved for application use.
    • Seek mode is not supported.
  • Compatibility with SceneExaminer - Only the left mouse button has defined behaviors. Pan and zoom behaviors require pressing a keyboard key while dragging the mouse.
Remarks

Usage:

  • Left Mouse: Rotate the scene.
  • Left Mouse + Ctrl: Pan the scene.
  • Left Mouse + Shift: Zoom in/out.
  • Mouse Wheel: Zoom in/out the scene (zoom center is the mouse cursor location).
See Also