Streamline seeding

It is vital to choose the starting points of streamlines well. The lines should be evenly distributed on the screen, and it is not enough to spread the seed points evenly to achieve that. That is because streamlet length may be different and there may be divergence and convergence areas influencing line density. It is usually necessary to apply sophisticated flow-guided seeding algorithms. However, in case of the finite element data, it is possible to count the number of intersecting streamlines for every element to determine if any more lines in that region are necessary. Furthermore, the density may be controlled locally in every element using data like flow velocity.