This technique is not limited to paper, you can apply to feather or leaf or any other stuff you like.
You need those to follow this tutorial:
(1) cebas thinkingParticles
(2) Blur's Random Walk plugin (free). You can download from MAX Plugins.de.
Here are some important screenshots of each steps / parameters:
You can find RandomWalk in Force/Blur's Particle & Dynamics
Viscosity: higher value make particles move more randomly, but in the end, particles will attract to specific points in space (attractor: is a set towards which a variable, moving according to the dictates of a dynamical system, evolves over time---Wikipedia ) :
Visual representation of a strange attractor---Wikipedia :
To avoid this effect, we can increase the %Walk:
The Alignment Operator can randomize rotation of your geometry (paper):
Spin operator give more natural movement to papers:
In the SC operator, remember to set parameters as follow, otherwise the paper will freeze...
Use PSelection to manually pick up particles in the scene that penetrate to each other, and use Particle Die to delete them:
Tutorial: random movement in thinkingParticles