Zooming in on objects

Question

I've read a few posts regarding the question of how to make sure objects don't disappear when zooming in. The suggestion is that a low front clip distance (i.e., setFrontClipDistance()) will make that happen. I have played around with that with some improvement, but I still get some objects to disappear.
My zooming is done by resetting the scale...is there something I should or should not be doing here? For what it's worth, here are some relevant snippets of code.
In my method for creating the universe
universe = new VirtualUniverse();
parentLocale = new Locale( universe );
viewplatform = new ViewPlatform();
viewplatform.setActivationRadius( 5000.0f );
// sceneGraph.addChild(viewplatform);
view = new View();
view.setVisibilityPolicy( View.VISIBILITY_DRAW_VISIBLE );
PhysicalBody physicalbody = new PhysicalBody();
PhysicalEnvironment physicalenvironment = new PhysicalEnvironment();
view.setPhysicalBody( physicalbody );
view.setPhysicalEnvironment( physicalenvironment );
view.addCanvas3D( canvas );
view.attachViewPlatform( viewplatform );
viewGraph = new BranchGroup();
...a VisTransformGroup extends TransformGroup
viewTransform = new VisTransformGroup( "Global Transform" );
viewTransform.setScreenCenter(new Vector3d(0.,0.,0.));
viewGraph.addChild( viewTransform );
viewTransform.addLast( viewplatform );
view.setFrontClipPolicy( view.VIRTUAL_SCREEN );
view.setBackClipPolicy( view.VIRTUAL_SCREEN );
view.setBackClipDistance( 3000.0 );
view.setFrontClipDistance( -30.0 );
viewGraph.setCapability( Node.ALLOW_AUTO_COMPUTE_BOUNDS_READ );
...I create a global TransformGroup, called scaleTG
// Scale
Transform3D scale = new Transform3D();
scaleTG = new TransformGroup(scale);
the zoom method modifies the scale transformation...
public void zoom(int value) {
      Transform3D rotTrans = new Transform3D();
      rotateTG.getTransform(rotTrans);
      Transform3D translation1 = new Transform3D();
      translation1.setTranslation(screenCenter);
      double sfactor = 1.0 + Math.abs(value) / 200.0;
      if (value > 0) {
         sfactor = 1.0 / sfactor;
      Transform3D scale = new Transform3D();
      scale.setScale(sfactor);
      Transform3D translation2 = new Transform3D();
      screenCenter.negate();
      translation2.setTranslation(screenCenter);
      screenCenter.negate();
      Transform3D lastTransform = new Transform3D();
      scaleTG.getTransform(lastTransform);
      VisTransform3D curTransform = new VisTransform3D(
            "CurrentWorkingTransform");
      curTransform.mulInverse(rotTrans);
      curTransform.mul(translation1);
      curTransform.mul(scale);
      curTransform.mul(translation2);
      curTransform.mul(rotTrans);
      curTransform.mul(lastTransform);
      scaleTG.setTransform(curTransform);
      Vector3d vScale = new Vector3d( );
      curTransform.getScale( vScale );
      onScale( vScale );
   }

Answer 1

Your objects will disappear regardless if your view platform is moved between them and the center point. One thing you can do is move the center point to the region of interest.