When you create a membrane structure with the program WinTess3, we always simulate the membrane through a mesh. The mesh is formed by a set of segments joined by their ends forming a frame more or less regular. The program supports triangular or quadrangular frames (squares, rectangles, diamonds, trapezoids, etc.). The user, using the appropriate menus, choose the type of mesh that considers more convenient.
However, in this process, there is always a delicate moment for the decision of mesh size. It is to find a balance between accuracy and effectiveness.
If the mesh is too dense or thick, the whole process goes on forever. Both the form finding and the calculation become very long and it is possible that the program hangs if the used computer is not very powerful. Nevertheless the obtained forms will be very smooth.
On the contrary, if the mesh is too sparse or dispersed, the processes of form finding and numerical calculation are much faster. However, in this case the surface obtained is very faceted with the pattern and accuracy of the calculation will be very poor.
Thus, the virtue is in find a mesh that has the minimum bar and knots, but to provide an image adequate for calculation and patterning. It is not easy to say how this is accomplished as it depends on many factors, but especially of shape of the perimeter. Through experience, we can give a series of tips that tend to produce quite adequate meshes.
- It is better to make a mesh little dense than too dense. It is always possible to refine (more dense) mesh later. On the other hand WinTess3 cannot make a mesh less dense.
- We must ensure that the one side of the perimeter (the outer side) should have between 6 and 10 nodes (points).
- If there are no cables of on the perimeter as entire perimeter is fixed, then we will make sure that the diagonal should have between 8 and 12 nodes.
With these criteria, we usually obtain the best meshes for form finding and the calculation. It is possible to refine the mesh during patterning phase, but for this you will need to know the width of the canvas that is going to be used, as it is absurd to use a very fine mesh patterns for a very wide canvas.