How to display stream lines from 3D vector field with tvtk and Python

Hi all, I am trying to visualize stream lines from 3D velocity fields in a format lets say 10x10x100x100x3 where I have ten time steps, ten slices, 100x100 pixels inplane resolution and 3 vector components for each voxel. For every time step, my velocity field changes a bit. How can I display (moving) streamlines of my velocity field? Cheers Randall