When designing this structure, my initial idea was to create a structure that was suspended on either end, but also had the ability to enter from either side. I was also intrigued by the work we have done with using variable sine curves and wanted to implement this into my design.
It is worth nothing that I designed all of my input parameters to be parametric from the start (that is, they are all able to be changed), so the line between the 2 and 3 unit task is not super clear. The first and second images above roughly correspond to the two stages respectively. Regardless, the path I followed was as follows.
I started by defining an initial sine/cosine curve with parameters for the length defined by a start, stop, and step value. I also had inputs to change the frequency and amplitude of the curve itself. I defined the y parameter of the curve based on the inputs (namely, whether a sine or cosine curve was chosen, and the specific parameters of this curve), and had a slider for the height, or essentially how tall the area where people can walk under is at the edges. From these points, I used Nurbs curve to fit a curve to the points. I found that this fit the effect I wanted best.
Next, to create the other side of the structure, I used the mirror block, and mirrored the curve about the XZ plane. I implemented a slider to choose the distance that the mirrored curve would be away from the origin curve, essentially controlling the width of the structure. I used these points to create the XZ plane and then mirrored it about there.
Next, I created the backbone of the structure, or the curve in the middle. I did this by using the above mentioned slider for the distance from the original curve, and dividing it by 2, to place the backbone curve directly in the middle of the two curves. I defined the x coordinates of the start and end points to align with the start and end of the sine curves, using the same initial sliders. I then defined the center, top point by implementing a slider to adjust the height of the ridge, and feeding it into the z coordinate of the point. I then merged these 3 points, and used the IntCrv block to create the curve. I learned that the order in which you pass these parameters into the merge affects how the curve will be constructed, so I had to change to doing start, then middle, then end.
Next, I merged all 3 curves, and passed this into the loft block, making the surface not closed, as per the tutorial.
After this, I formed the actual structure. I used the LunchBox plugin. First, I created the space truss structure surrounding my surface. I created 3 sliders for the divisions in the local x and y of the structure as well as the depth of the truss itself. I then fed the product of this spacetruss block into the pipe block, and added a slider to define the radius of the pipe. This created the actual structure of my shelter.
Next, I created the panels for my structure. I wanted to have them on the inside of the structure so that the actual structure itself was the main focus of the piece. As such, I used the quads/panels feature, and then using the scale block, passed in the area of the panels as well as a scale factor, and finally passed these inputs into an offset block (controlled by a slider) to offset the panels to the inside of the space truss.
Finally, I created spheres at the nodes, whose radii were controlled by a slider. This was primarily an aesthetic choice.
A key insight I learned is that although I have all these sliders, and they all work for their intended function, you do not always want to use all of them, as it makes the structure look bad. The screenshots I’ve included above are from designs I developed that looked interesting (although their structural practicality is another question), but there were lots of iterations that just looked weird, even though they worked.