I've had my head in circular design so long, I couldn't say exactly when or how it began... but I know that designing rainwater systems, specifically, escalated to a major life goal after I picked up copies of Art Ludwig's books "Water Storage" and "Create an Oasis with Greywater," which my Amazon history tells me was April 26, 2016. If you've never read them, pick up a copy, then join me in my obsession!
- Water Storage: Tanks, Cisterns, Aquifers, and Ponds for Domestic Supply, Fire and Emergency Use--Includes How to Make Ferrocement Water Tanks
- The New Create an Oasis with Greywater 6th Ed: Integrated Design for Water Conservation, Reuse, Rainwater Harvesting, and Sustainable Landscaping
This vessel has lived rent-free in my head for almost a decade. I finally have the tools to start re-creating it.
I'll be using Grasshopper in Rhino 8.0 (I'm a total beginner) to model the shape with parameters I can then adjust to make a variety of iterations of this beloved vessel... here we go!
My grasshopper experiments and reflections during the parametric design process follow.
- Height of vessel - variable
- Symmetry - this will be fixed for now - a round vessel
- Radius throughout - variable
- Height of the "bulge" - variable
- Height and radius of the lip - variable
First thought - Maybe try interpolating a curve for the outer edge and then make a ring out of that shape? Problem 1 - Not sure how to do that. Problem 2 - these points don't seem intuitively parametric.
Second thought - Starting with the idea of a circle, I want a stack of multiple circles always with the same center. I can make a vertical line, then divide it, then use the resulting points as the centers for a vertical stack of multiple circles. I want to parametrically control the height of the vessel, so I'll use Line SDL with a Slider to input the line length.

Ok, so that's a cone. Not quite right. I suppose I don't want the radius values to be a sequential range. Returning to the first-thought design, I want to define the outside edge as a curve that I can play with. Instead of a panel, I'll try a Graph Mapper.
Now we're getting somewhere! The Perlin and Bezier graph types both had interesting results. I'm going to play with the Bezier for now. Adding a Multiplication node lets me expand and contract the radius of the vessel radius with a Slider.
Perlin:

Bezier:

This is also reminding me of mid-century pendant lights, so I'm going to save the progress to come back to this point to take it in a different direction for another day!

Moving on to the beveled lip... I had the range of rings equal to the height of the line/ number of divisions, so I'm going to play around to add some more circle divisions and control them with a second Graph Mapper. This ultimately worked, and I simply applied Merge to combine the two range > graph > multiplication transformations.

Loft!

I am pretty happy with that for a good start! Now to play around.

Thanks for coming along with me on my first step toward recreating the Art Ludwig Water Storage Vessel!