Extended Selection

$OIVHOME/examples/source/Inventor/Features/

ExtSelection/extSelection.cxx.

C++ :

int
main( int argc, char** argv )
{
  ...
  // Creation and initialization of
  // the lasso as the root of the
  // scene graph.
  // The selection policy is
  // SINGLE, the shape of the lasso
  // is a rectangle and the color
  // of the lasso is green
  root = new SoExtSelection;
  root->ref();
  root->setLassoColor( SbColor( 0, 1, 0 ) );
  root->policy = SoSelection::SINGLE;
  root->lassoType = SoExtSelection::RECTANGLE;
  ...
  // Building the scene graph with children under
  // the SoExSelection node.
 
  ...
  viewer = new SoXtExaminerViewer( myWindow );
  viewer->setSceneGraph( root );
 
  // Selected objects are highlighted with a surrounded bounding box.
  viewer->setGLRenderAction( new SoBoxHighlightRenderAction() );
 
  viewer->redrawOnSelectionChange( root );
  viewer->setTitle( "Selection Test" );
  viewer->show();
 
  SoXt::show( myWindow );
  SoXt::mainLoop();
  return 0;
}

C# :

// Creation and initialization of
// the lasso as the root of the
// scene graph.
// The selection policy is
// SINGLE, the shape of the lasso
// is a lasso and the color
// of the lasso is red
root = new SoExtSelection();
...
root.SetLassoColor( new SbColor( 1, 0, 0 ) );
root.policy.Value = SoSelection.Policies.SINGLE;
root.lassoPolicy.Value = SoExtSelection.LassoPolicies.PART;
root.lassoType.Value = SoExtSelection.LassoTypes.LASSO;
...
viewer = new SoWinExaminerViewer( this, "", true, SoWinFullViewer.BuildFlags.BUILD_ALL, SoWinViewer.Types.BROWSER );
viewer.SetSceneGraph( root );
// Selected objects are highlighted with a surrounded bounding box.
viewer.SetGLRenderAction( new SoBoxHighlightRenderAction() );
 
viewer.RedrawOnSelectionChange( root );
viewer.SetTitle( "Selection Test" );
 
viewer.Show();
viewer.ViewAll();

C# :

// Creation and initialization of
// the lasso as the root of the
// scene graph.
// The selection policy is
// SINGLE, the shape of the lasso
// is a lasso and the color
// of the lasso is red
selectionRoot = new SoExtSelection();
selectionRoot.useOverlay( true );
selectionRoot.setLassoWidth( 2 );
selectionRoot.setLassoColor( new SbColor( 0, 1, 0 ) );
// selectionRoot.setOverlayLassoPattern ((short)0xE0E0);
// selectionRoot.animateOverlayLasso (true);
selectionRoot.policy.setValue( SoSelection.Policies.SINGLE );
selectionRoot.lassoType.setValue( SoExtSelection.LassoTypes.NOLASSO );
selectionRoot.lassoPolicy.setValue( SoExtSelection.LassoPolicies.PART );
 
// Add an event callback so we can receive key press events
SoEventCallback myEventCB = new SoEventCallback();
myEventCB.addEventCallback( "com.openinventor.inventor.events.SoKeyboardEvent", new MyKeyPressCB(), selectionRoot );
 
...
// Building the scene graph with children under
// the SoExSelection node.
...
 
// Create a viewer for viewing the scene
SwSimpleViewer myViewer = new SwSimpleViewer( SwSimpleViewer.EXAMINER );
myViewer.getArea().setGLRenderAction( new SoBoxHighlightRenderAction() );
myViewer.getArea().redrawOnSelectionChange( selectionRoot );
myViewer.getArea().setSceneGraph( selectionRoot );
 
panel.add( myViewer );
add( panel );

FastEditing mode

The fast edit mode allows using the fast edit features from the SoSeparator node. It enables Open Inventor to cache the frame buffer and the depth buffer in order to edit a sub scene-graph without re-rendering the full scene graph. Saving the buffers and restoring them instead of re-rendering the scene graph is very efficient for large scenes that may be difficult to render at interactive frame rates. This mode is used in the SoExtSelection node in order to perform fast animation for the lasso and optionally fast rendering of a custom scene graph.

Enable or disable this feature by using the method useFastEdit(). By default this feature is disabled.

Another advantage of this mode is that it does not require high-end hardware features like overlay planes to render selection graphics at interactive rates. Also, unlike the default mode, it does not require GDI functions (which breaks Aero on Microsoft Windows Vista).

Note: See the section called “Fast Editing” for more information about fast editing.

Selection callbacks

The selection callbacks are called when the selection begins, moves and ends. They can be used for example to do specific 2D rendering over the scene or doing regular selection of objects in the scene. The callback function will be called with the cursor position in pixels and also the corresponding position in 3D space.

Use the following methods to set the selection callbacks:

• SoExtSelection::setStartSelectionCallback()
• SoExtSelection::setMovingSelectionCallback()
• SoExtSelection::setEndSelectionCallback() You have to return TRUE if you handle the event or FALSE if you want to apply the default behavior from the SoSelection class.

Custom scene graph

In fastEdit mode you can use the method setSelectionSceneGraph to specify a scene graph to be rendered as custom selection feedback while a selection operation is active. You can also modify this scene graph dynamically during a selection operation, using the selection callbacks.

Examples

An example of the new behavior is available in the directory:

$OIVHOME/examples/source/Inventor/Features/FastSelection

This demo shows several types of custom selection feedback like a ruler and an aperture. The geometry used in this example is huge on purpose in order to show the rendering performance improvement when the fast edit feature is used.