By defining perimeter of the pattern, we can generate a pattern more comfortably than the “by triangles” method. However, once the pattern is created, it is very important to check the triangularization that WinTess3 proposes in order to avoid incorrect patterns due to an error in data entry or malfunction of the program when it comes to generating these triangles.

To define a pattern we start with the furthest point away from the center of the pattern. In most cases this point is the end of a geodesic line which serves as the edge of the pattern that we are going to create. Other times this point will be a corner of the membrane which does not match any geodesic line.

From this point on, and rotating clockwise, we mark the rest of points on the perimeter. When we finish by **marking the starting node again** (that is to say, we have completed the perimeter), the program creates the pattern.

To further facilitate the work, when we press the second point on a geodesics line, the program understands that we want to use that geodesic line and automatically marks all the remaining points of the same geodesic. This speeds up the work of creating patterns.