An Away3D scene usually takes up the full width and height of the embedded swf file in the browser. In Flash you can easily solve this problem by masking the Away3D view.
The same thing goes for Flex, but Flex has it’s own measuring and sizing methods. I’ve come to know that it’s a great thing as regards to performance, maintainability and scalability of your component to adapt to the Flex Framework.
In this case, I’ve extended a Flex component. The new Component contains an Away3D scene, which wants to take up the full width and height of my Flex Application. To solve this we need to override the updateDisplayList method. This method get’s called by the Flex Framework every time something in the measuring has changed. Here’s how it looks in code:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void { super.updateDisplayList(unscaledWidth, unscaledHeight); // Set the clipping of the 3D scene to make sure only the visible elements are rendered, // this is great improvement for the performance var clipping:RectangleClipping = new RectangleClipping(-this.width/2, -this.width/2, this.width/2, this.width/2); // Asign the clipping to the _view3D, in this case a private variable within my class _view3D.clip = clipping; // Remove the old mask if there is one if (_mask != null) { this.removeChild(_mask); } // Create a new mask _mask = new Sprite(); _mask.x = this.x; _mask.y = this.y; _mask.graphics.beginFill(0xFF0000,1); _mask.graphics.drawRect(0, 0, this.width, this.height); _mask.graphics.endFill(); // Add it to the displayList this.addChild(_mask); // And assign the mask to the view3D _view3D.mask = _mask; // And center the view3D in the available space _view3D.x = this.width / 2; _view3D.y = this.height / 2; } |
So as you see above, it’s quite straighforward. The clipping in the beginning of the method is not necessary for the masking, but since only the masked area is being displayed, there’s no need to render the invisible parts of the view3D.
