Controls:
w,a,s,d - move camera
mouse --- aim camera
r ------- reset particle positions
t ------- reset particle positions, small initial volume
p,o ----- pause,resume evolution
l ------- manually advance evolution
z,x ----- scale attractor smaller,larger
arrows -- rotate attractor
1 ------- Lorenz attractor
2 ------- Roessler attractor
3 ------- Lu Chen attractor