hitTestObject area

Hello !:slight_smile:

Iā€™m trying to make a simple animation with moving bubbles.
I am using the hitTestObject method to detect collision between bubbles.
The problem is that sometime bubbles seems to bounce quite far from other bubbles (about 10 pixels i guess).

You can see the swf here

Does someone know why ? Should i use the hitTestPoint for a better result ?

Thanks