Re: Blowing paper

Ncloth probably would work better. it has controls for how the paper interacts with air which can lend a pretty realistic look and control.

As for randomizing particle instance rotations you need to do a couple of things:

1. On the particle shape in the attribute editor click General under Add Dynamic Attributes section. Name it rotatePP and set it as a vector datatype, choose per-particle(array) as the attribute type.

2. Right click on this new particle attribute (should be lumped in with velocity, world velocity, acceleration, etc.) and choose Creation Expression

3. In the expression editor do something simple to start like rotatePP = <>. That will make rotatePP random +-30 in x +-60 in y and +- 30 in z. You wont see anything happen to the instances yet, this just applies data to the particle.

4. This step will tell the instancer to use the rotatePP data you applied in step 3 to the instanced objects. Again on the particleShape in the attribute editor expand the Instancers (Geometry Replacement) secion and scroll down to Rotation Options. Change the pull down next to 'Rotation' from None to rotatePP (it shows up there when you create the attribute).

5. Now restart and play from the beginning you should have randomly rotated instances. You can use a Runtime expression to actually animate the rotation, which can be tedious. Or you can use AimDirection -> Velocity to make the instances orient to the direction the particles are moving.