Video:
https://drive.google.com/open?id=1I4ietWbcI_a4xDuA_YQEPNe0VnShRw5r
Description:
I created a thousand small circles using particle classes and give them random size and mass. I didn’t seal the ceiling of the “zone”, and at first the particles will fall from sky. There is gravity, air friction in the whole “zone”, and in the white area, there is resistance that slows the speed very much. And there is wind force given by the mouse coordinates, so we can move the particles by moving the mouse. If the circles touches the side, it will bounce back. But if we leave our mouse at the bottom of the “zone”, all the particles will stop moving and gather together.
Image:
