Figure 2.
Schema of the intersection of an electron trajectory and a triangle and the change of region associate with it. A: single triangle where the new region is Au. B: two triangles overlap and ambiguity in the determination of the new region. C: intersection of two triangles with discontinuity in the determination of the new region. D: small gap approach to resolve these two problems. E: another ambiguity in the determination of the new region (the red dash lines define the lateral limit of the Au region of the plane shape).