x: 5*sin(v)*cos(u)+u*v
y: 6*v
z: 3*u
u[-20,20] steps 800
v[-20,20] steps 800
x: 2*sin(v)*cos(u)-u*v*sin(u)
y: sin(12*u)-9*u*v
z: 13*v
u[-3,15] steps 200
v[-3,14] steps 200
x: 5*v*sin(u)
y: 2*u*v+sin(2*v)
z: 3*v+4*u
u[-1,6] steps 500
v[-5,4] steps 200
