Hi,
Not sure if you already got the answer to this, but if you’re using version 12 of C4D, inside the dynamics tag there is now a button called ‘set initial state.’ I believe this is exactly what you’re looking for.
Here’s how to use it:
Make sure you’re on frame 0 of your animation.
Set up your coins so they’ll fall once you press play – in other words, place them a little above the surface you want them to fall onto.
Press play, and let them fall and scatter. Let it keep playing until they settle to a stop.
Click the ‘set initial state’ button. Now when you go back to frame 0, your coins should be sitting on the ground, or in your case, the inside of the bottom of the piggy bank’s belly.
It’s as easy as that.