private void InitializeParticles(int n)
{
var particles = new Particle[n];
for (var i = 0; i < particles.Length; i++)
{
// generate a flat random cube
particles[i].Position.X = Rand(0.2f);
particles[i].Position.Y = Rand(0.02f);
particles[i].Position.Z = Rand(0.2f);
// move particles outwards
particles[i].Position += particles[i].Position.Normalized() * 0.8f;
// calculate velocity perpendicular to the direction towards the gravity center and the y-axis
particles[i].Velocity = Vector3.Cross(particles[i].Position, -Vector3.UnitY);
}
// upload data into the Ping buffer and initialize the pong buffer to the same size
_buffers.Init(BufferTarget.ArrayBuffer, particles);
}
