Maya particles making falling petals

This is the author in the foreign website to learn some skills and do the tutorial. First look at the picture.

New scene, create a plane, move, and set the value of the u/v slice.

Create the petals, as shown in the picture.

Select plane, create the particle emitter, use emit from object, and set the parameters, as shown.

Create a gravitational field.

Exert a confusions field.

Now, there are already falling particles that associate the petals with the particles.

Create an expression.

As pictured.

Associates an expression with an rotation.

Now, the petals can rotate. Of course, it's not over yet. Then create the floor.

Petals across the ground, we need to drop the petals on the ground and stop the rotation. Select particle and ground, make collide command, set friction and elasticity, as shown in Fig.

Select ParticleShape1 to continue editing an expression.

Specifies the material, the simple flower falls the effect to complete.

An expression:

particleShape1.rbb=rand(0,360);
particleShape1.rbb+=0.001;
float $vel = (particleShape1.velocity)/2000;
particleShape1.rbb += $vel;