The site Membranes24.com provides a free online service for form finding of tensile fabric structures. They have several basic shapes where you only have to provide node locations. After clicking on “Design” in the top menu, you can select from a variety of different topologies for your membrane structure. For our example, we select “Center arch” in order to do the form finding for a membrane structure consisting of six fixed edge points connected by cables and one center arch.
If you have mastered the form finding of your own membrane structures, you can import the geometry into Google SketchUp for postprocessing and rendering.
See this video tutorial on how you can do form finding of tensile structures with just a few clicks: