[away3d] FrustumClipping makes all Sprite3D objects disappear near screen borders

[Gleb Kobzar]

Hello,

I have a problem with Sprite3D and FrustumClipping. When I use
Rectangular or Nearfield clipping Sprite3D objects are displayed
correctly. But FrustumClipping makes all Sprite3D objects disappear
near screen borders. I noticed they disappear when Sprite3D center/
pivot point moves out of view borders (moving over the surface with
arrows):
http://www.kollaps.com.ua/gb/SpriteFrustum/

Here are sources for Flash CS4:
http://www.kollaps.com.ua/gb/SpriteFrustum/SpritePlants.zip

And AS3 code related to Sprites, view, scene and camera setup:

function initEngine():void
{
        scene = new Scene3D();

        scamera = new SpringCam();
        ...
        clipping= new FrustumClipping({minZ:50, maxZ:2000});

        var basicrenderer:BasicRenderer = new BasicRenderer();

       view = new View3D();
       view.renderer=basicrenderer;
       //view.renderer=Renderer.INTERSECTING_OBJECTS;
       view.x = stage.stageWidth / 2;
       view.y = stage.stageHeight / 2;

        view.scene = scene;
        view.camera = scamera;
        view.clipping = clipping;

        addChild(view);
}
function initMaterials():void
{

        floorMaterial = new TransformBitmapMaterial(Cast.bitmap(GrassOld), {
scaleX:0.05,    scaleY:0.05, repeat:true});
        treeMaterial = new BitmapMaterial(Cast.bitmap(OakTree));
        //treeMaterial = new BitmapMaterial(new OakTree(362,263*2));
}
function initObjects():void
{

        floor=new Plane();

        floor.height=PLANE_LENGTH;
        floor.width=PLANE_LENGTH;
        floor.segmentsH=PLANE_SEGMENTS;
        floor.segmentsW=PLANE_SEGMENTS;
        floor.material=floorMaterial;

        view.scene.addChild(floor);

        Trees=new Array();
        var sprite:Sprite3D;
        var spriteMesh:Mesh;

        for (var i:int = 0; i <100; i++) {
                spriteMesh=new Mesh();
                sprite = new Sprite3D(null,362,526);

                spriteMesh.x=PLANE_LENGTH*Math.random()-PLANE_LENGTH/2;
                spriteMesh.z=PLANE_LENGTH*Math.random()-PLANE_LENGTH/2;
                spriteMesh.y=0;
                sprite.material=treeMaterial;

                sprite.scaling=2.0+2.0*Math.random();

                spriteMesh.addSprite(sprite);
                view.scene.addChild(spriteMesh);
        }

}

You may notice that I create a Mesh object for each sprite, because I
would need to add interactivity and zDepth actions. By the way without
this all sprites disappear under Frustum Clipping.

May be I'm doing something wrong?

Thanks beforehand for advice