Package com.openinventor.inventor.nodes

Class SoLevelOfDetail

java.lang.Object
com.openinventor.inventor.Inventor
com.openinventor.inventor.misc.SoBase
com.openinventor.inventor.fields.SoFieldContainer
com.openinventor.inventor.nodes.SoNode
com.openinventor.inventor.nodes.SoGroup
com.openinventor.inventor.nodes.SoLevelOfDetail
All Implemented Interfaces:
SafeDisposable
public class SoLevelOfDetail extends SoGroup
Level-of-detail switching group node. The children of this node typically represent the same object or objects at varying levels of detail, from highest detail to lowest. The size of the objects when projected into the viewport is used to determine which version to use (i.e., which child to traverse).

The size is computed as the area of the screen rectangle enclosing the projection of the 3D bounding box that encloses all of the children. When rendering, this size is compared to the values in the screenArea field. If the size is greater than the first value, child 0 is traversed. If it is smaller than the first, but greater than the second, child 1 is traversed, and so on. If there are fewer children than are required by this rule, the last child is traversed. The screenArea field contains just 0 by default, so the first child is always traversed.

The size calculation takes the current complexity into account. If the complexity is 0 or is of type BOUNDING_BOX, the last child is always traversed. If the complexity is less than .5, the computed size is scaled down appropriately to use (possibly) a less detailed representation. If the complexity is greater than .5, the size is scaled up. At complexity 1, the first child is always used.

Note that the SoLOD node is similar to SoLevelOfDetail, except the switching between levels in the SoLOD node is based on distance from the camera, which is faster than using screen area.

File format/default:

LevelOfDetail {

    screenArea 0
}

Action behavior:

SoGLRenderAction, SoRayPickAction, SoCallbackAction
Only the child with the appropriate level of detail is traversed.

SoGetBoundingBoxAction
The box that encloses all children is computed. (This is the box that is needed to compute the projected size.)

Other actions

All implemented as for SoGroup.

See Also:

  • Field Details

    • screenArea

      public final SoMFFloat screenArea
      Areas to use for comparison.

  • Constructor Details

    • SoLevelOfDetail

      public SoLevelOfDetail()
      Creates a level-of-detail node with default settings.

    • SoLevelOfDetail

      public SoLevelOfDetail(int nChildren)
      Constructor that takes approximate number of children.