Class SoViewingCube

  • All Implemented Interfaces:

    public class SoViewingCube
    extends SoNode
    (Preview Feature) Interactive cubic shape to control the orientation of a camera.

    Preview Feature means 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.

    The viewing cube is an interactive shape that indicates the current orientation of a camera (like a "compass" or "gnomon") and also responds to user actions by re-orienting the associated camera to one of the predefined orientations. These orientations are defined so that the camera will be in front of a selected part of the bounding cube of the scene.


    When the mouse cursor is over the viewing cube, the part (face, edge, or corner) that is under the cursor is highlighted with the selectionColor. Then if the left mouse button (button 1) is clicked (pressed and released), the selected part of the viewing cube is used to define the new orientation.

    The viewing cube can be used as a replacement for the X/Y/Z camera orientation buttons implemented in many graphical user interfaces. It provides even more possibilities thanks to the pickable edges and corners of the viewing cube which offer 26 different viewing positions. However, if the edgeSize is set to 0, the edges and corners are not pickable. In this case the user can only select six different positions.

    The camera controlled by the viewing cube is defined by the field sceneCamera. This is normally the same camera that the 3D viewer is controlling. In this case both the viewer and the viewing cube control the camera and the viewing cube orientation is synchronized with the sceneCamera.

    In principle, as SoViewingCube is a standard class derived from SoNode, it can be inserted in any scene graph and used with a classical viewer or SceneExaminer class. In that case the viewing cube will correctly indicate the camera orientation, but it will not be convenient for the user to use the viewing cube's interaction features. These viewers are always in either viewing mode (mouse events control the camera) or in selection mode (mouse events are sent to the scene graph). In viewing mode, the viewing cube will not respond to mouse clicks, but in selection mode the viewer will not respond to mouse clicks.

    Therefore we recommend to use the SceneOrbiter class as the viewer when using a viewing cube. SceneOrbiter is a "mode less" viewer. A mouse click without moving the mouse is interpreted as a selection (for example triggering the viewing cube behavior), but a mouse click and "drag" is interpreted as controlling the camera. For convenience, the SceneOrbiter automatically adds a viewing cube to the scene graph.

    The viewing cube is rendered in a corner of the render area. Its size and position in the render area are defined by the size and position fields.

      viewing cube at the top right corner of a render area

    Rendering customization

    When the mouse cursor is moved on top of the viewing cube, the part that is under the cursor is highlighted using the color defined by the field selectionColor. The colors of the cube can also be personalized with 3 fields: faceColor, edgeColor and cornerColor.

    Cubic shape customization

    The shape of the viewing cube can be customized by several fields. The shape of the edges and corners is defined by the field edgeStyle. The edges can form a sharp corner, be rounded or be flat (beveled). The size of the edges and corners relative to the cube face is defined by the field edgeSize.

    Each flat face of the viewing cube can also be customized. By default the text Top/Bottom/Front/Back/Left/Right appears on the center of each face according to its orientation. The six fields facePosX ... faceNegZ allow the application to replace the default appearance of each face with an image. Note that these images should have a transparent background so the highlight color is visible when the cursor is over the face.

      viewing cube custom faces with F/R/B textures


    The viewing cube's opacity may vary depending on the distance between it and the cursor.

    • if the cursor is far from the center of the cube, the opacityMin is applied.
    • if the cursor is very close or over the cube, the opacityMax is applied.
    • otherwise the opacity varies in the range [opacityMin, opacityMax]

    When the cursor moves in an area close to the cube but not over the cube and if the opacityMin and opacityMax differ, a rendering of the scene occurs each time the mouse is moved in this area, which can lead to slowing down of the application.

    By default, opacityMin and opacityMax are set to 1, which means the cube is always opaque.


    • Some visual artifact on semi transparent ViewingCube when you use NO_SORT transparency type.
    • The opacity of the ViewingCube is only updated on a mouse move event without button pressed. Therefore the opacity won't change if you move the mouse without pressing a button.

    Compass The compass is not impacted by the varying opacity, thus independently from the fields opacityMin and opacityMax


    To provide a better user experience, picking a part of the viewing cube does not immediately change the camera orientation. A smooth animation is done between the current camera orientation and the new orientation. The duration of the animation is defined by the animationDuration field.

    Note that the animation of the camera is done in such a way that the default text of each face Top/Bottom/Front/Back/Left/Right are always legible.

    File format/default:

    ViewingCube {

      sceneCamera NULL
      size (150.0, 150.0)
      position TOP_RIGHT
      edgeStyle ROUND
      edgeSize 0.4
      selectionColor cyan
      faceColor 0.8 0.8 0.8
      edgeColor 0.8 0.8 0.8
      cornerColor 0.8 0.8 0.8
      animationDuration 0.8
      upAxis "Y"
      facePosX ""
      faceNegX ""
      facePosY ""
      faceNegY ""
      facePosZ ""
      faceNegZ ""
      opacityMin 1
      opacityMax 1
      compass NULL

    See Also:
    • Field Detail

      • sceneCamera

        public final SoSFNode sceneCamera
        Camera which is synchronized with this viewing cube. When using a viewing cube with a SceneOrbiter, the method SceneOrbiter.enableViewingCube(true) automatically sets the field sceneCamera.

        However, to use a viewing cube with a SceneExaminer, the following code sample gives an example to set the field sceneCamera.

         viewerExaminer = new ViewerExaminer();
         SceneExaminer sceneExaminer = viewerExaminer.getRenderArea().getSceneInteractor();
         SoViewingCube viewingCube = new SoViewingCube();
         viewingCube.sceneCamera.setValue( sceneExaminer.getCamera() );
         sceneExaminer.addChild( viewingCube );
      • size

        public final SoSFVec2f size
        Size of the viewport, in pixels, in which the viewing cube is drawn. Default is 150 pixels width, 150 pixels height.
      • selectionColor

        public final SoSFColor selectionColor
        Color used to highlight the part of the viewing cube that is under the cursor. Default is cyan (0,1,1).

        The following image shows the highlighted edge behind the cursor when selectionColor = (1,0,0)

      • faceColor

        public final SoSFColor faceColor
        Color used to render the faces of the cube. Default is gray (0.8,0.8,0.8).
      • edgeColor

        public final SoSFColor edgeColor
        Color used to render the edges of the cube. Default is gray (0.8,0.8,0.8).
      • cornerColor

        public final SoSFColor cornerColor
        Color used to render the corners of the cube. Default is gray (0.8,0.8,0.8).
      • facePosX

        public final SoSFFilePathString facePosX
        Texture to customize the face's appearance which has a "Right" label by default. This field defines the name of the file which contains this texture.

        The standard image file formats are supported. See SoRasterImageRW for the list. The image format must handle an alpha channel in order to allow the selected face to be highlighted with the selectionColor.

      • faceNegX

        public final SoSFFilePathString faceNegX
        Texture to customize the face's appearance which has a "Left" label by default. See facePosX for detail.
      • facePosY

        public final SoSFFilePathString facePosY
        Texture to customize the face's appearance which has a "Top" label by default. See facePosX for detail.
      • faceNegY

        public final SoSFFilePathString faceNegY
        Texture to customize the face's appearance which has a "Bottom" label by default. See facePosX for detail.
      • facePosZ

        public final SoSFFilePathString facePosZ
        Texture to customize the face's appearance which has a "Front" label by default. See facePosX for detail.
      • faceNegZ

        public final SoSFFilePathString faceNegZ
        Texture to customize the face's appearance which has a "Back" label by default. See facePosX for detail.
      • edgeSize

        public final SoSFFloat edgeSize
        Size of the edges, relative to the size of the faces. The size of the corners are also adjusted according to this value. When the edgeSize is 0, neither edges nor corners of the viewing cube can be highlighted or selected. Thus the viewing cube allows to select only 6 predefined positions of the camera.

        This field's value is clamped in a range [0-1]. edgeSize = 1 corresponds to 25% of the face's size. Default is 0.4.

        Depending on the edgeStyle value, the edgeSize defines either a radius (for ROUND style) or a width.

          Above is a viewing cube with edgeSize = 0

        Below are images of a viewing cube with different edgeSize=0.1 on the left column and edgeSize=0.25 on the right column.

      • animationDuration

        public final SoSFFloat animationDuration
        Duration of camera movement to reach the desired position. Any negative value of this field is equivalent to 0 (no animation). Default is 0.8 seconds.
      • upAxis

        public final SoSFEnum<Axis> upAxis
        Up axis of the scene. Setting the up axis allows the adjustment of the viewing cube rotations. Thus, this axis remains vertical at all times relative to the viewport, it is always parallel to the vertical border of the viewport. The chosen axis defines the initial position and orientation of the camera (front-top-right corner). . Default is Y.
      • opacityMin

        public final SoSFFloat opacityMin
        Defines the viewing cube opacity when the cursor is far from it. The value range is [0, 1].

        Default is 1.

      • opacityMax

        public final SoSFFloat opacityMax
        Defines the viewing cube opacity when the cursor is close to it or over it. The value range is [0, 1].

        Default is 1.

      • compass

        public final SoSFNode compass
        Defines an additional and optional scene graph to visualize a compass encapsulated in the viewing cube. This scene graph will have to be centered on (0, 0, 0) to be aligned with the center of the viewing cube. According to its size, the compass will be visible or not when the viewing cube is opaque.

        By default this field is NULL, so no compass is displayed. Some examples of simple compasses are provided in the folder $OIVHOME/examples/data/Inventor/ViewingCube/Compass

    • Constructor Detail

      • SoViewingCube

        public SoViewingCube()