Choose a 3D starting point

Before computing a flow line, you must select a starting point. Press the buttons ``XYwin'', ``XZwin'' and ``YZwin'', three windows appears (see figure 1.42), containing a projection of the mesh on the different planes.

Figure 1.42: 3 projection to choose a starting point.

To fix a point, click in 2 of the 3 windows with the left mouse button. Be aware that the point is in the mesh !
Once the point is chosen, you can compute a flow-line.