With this function you can retrieve the vertical velocity of a group of particles. The group value is that which was returned when you created the group of particles using the function physics_particle_group_end, and the function will return a value which is the combined value of the currently set flags.
|group||The particle group to get.|
vx = physics_particle_group_get_vel_x(group1);
vy = physics_particle_group_get_vel_y(group1);
The above code will get the horizontal and vertical velocity of the particle group indexed in the variable "group1" and store them in variables.