SoLevelOfDetail Class Reference
[Groups]
Level-of-detail switching group node. More...
#include <Inventor/nodes/SoLevelOfDetail.h>
Public Member Functions | |
| virtual SoType | getTypeId () const |
| SoLevelOfDetail () | |
| SoLevelOfDetail (int nChildren) | |
Static Public Member Functions | |
| static SoType | getClassTypeId () |
Public Attributes | |
| SoMFFloat | screenArea |
Detailed Description
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
SoLOD, SoComplexity, SoSwitch, SoGroup
Constructor & Destructor Documentation
| SoLevelOfDetail::SoLevelOfDetail | ( | ) |
Creates a level-of-detail node with default settings.
| SoLevelOfDetail::SoLevelOfDetail | ( | int | nChildren | ) |
Constructor that takes approximate number of children.
Member Function Documentation
| static SoType SoLevelOfDetail::getClassTypeId | ( | ) | [static] |
Returns the type identifier for this class.
Reimplemented from SoGroup.
| virtual SoType SoLevelOfDetail::getTypeId | ( | ) | const [virtual] |
Returns the type identifier for this specific instance.
Reimplemented from SoGroup.
Member Data Documentation
Areas to use for comparison.
The documentation for this class was generated from the following file:
- Inventor/nodes/SoLevelOfDetail.h