I am trying to make a sonar/radar that can detect when an object when it comes into its area. The sonar travels in an expanding circle, and the standard hittest obviously wont cut it. It is possible to hover an object outside the sonar range, yet still be detected (see attached file - you may have to rename is .swf). Please excuse its poor quality.
Ive done a mockup in Flash 8 with the effects but obviously I need to do this for real in actionscript to add to my confusion. I have the hitTest on the block as there maybe many objects in radar range in the final version…
So my 2 main questions are:
- How can i make the expanding circle in actionscript to represent the sonar
- How can I get a circular hitTest setup on the above
Any and all help appreciated 
Steve
