We are working on a seastead design. This is NOT a normal boat hull shape, but it is a bit like a trimaran in that their are 3 floats. Above the water there will be a big triangle frame, 80 feet front to back and 40 feet wide. The triangle frame will be a sort of truss structure that also doubles as a 4 foot high railing to keep humans from falling off. We will call the 3 points on the triangle "front", "left", and "right". And the edge between left and right we will call "back". There will be a floor and roof/ceiling (7 foot inside) the full area of the triangle. The enclosed living space will be 14 feet wide and 45 long on the centerline but one edge close to the back. There covered area around the living space make an open porch. The living area will have lots of windows in the font and back and some along the side. There will be 3 floats/legs/wings that will be the buoyancy. Each leg/wing will 19 feet long and have a NACA foil shape with 10 foot chord and 3 foot width. This makes for a "small waterline area" similar like a small oil platform but one that can move through the water easier because of the foil shape. Each of the 3 legs will be attached to the underside of the big triangle near one of the 3 points and going down into the water. The 3 wings will all be parallel with the blunt or "leading edge of the wing" forward so it is easy for the seastead to move forward. Each leg will be 50% under the water (so 0.5 * 19 feet) and the top 50% out of the water. On front of each leg on the top half that is out of the water will be a built in ladder. There will be 6 RIM drive thrusters, one on each side of the legs/wings about 3 feet up from the bottom. These will be aimed so they can push water past the wing and toward the back of the seastead. On top of the roof there will be solar all over. Behind the living area will be two supports going over the railing and 2 ropes going down to a dinghy that is a 14 foot RIB boat with 1 outboard motor that is sideways against the other side of the railing. When the seastead is moving the dingy will not feel the wind as the living area will block it. There are 3 stabilizers that look like a little airplanes, one attached near the back of each main seastead leg. The little airplane has a 10 foot wing-span, 1 foot chord, the body 6 feet long, and the elevator has a 2 foot wing-span and 6 inch chord. A small actuator makes the elevator angle up or down so it can adjust the angle of attack of the main wing of this stabilizer without needing a large actuator. While the thick part of the leg is 4 feet wide the back where the airplane will attach is very thin. And to get the airplane's center of lift to balance on the pivot a notch into the front/center of the wing only has to go about 25% of the chord of the wing. I would like to be able to have fairly simple set of 3D object (mostly cylinders really) and cables for tensegrity seastead design ideas that I could simulate in waves as was done in this video: https://www.youtube.com/watch?v=PsPeasVy248 What open source software can simulate simple designs in waves as was done in that video? That video is one of my designs. The two legs in the front have a cable connecting the bottoms so they make a triangle with a pivot point where it connects to the body, so they can move relative to the body. Then from the bottom of each of the front legs there are cables to the bottom of the back of the body. The back legs are a mirror of the front. I want to be able to simulate this kind of movement and the direction of the thrust moves as the legs are rotated. I would like to be able to simulate in higher and higher waves and be able to tell at what wave height some cable goes slack or the snap back tension is too high and it breaks (snap load, or snatch load). But I want to be able to visualize it so it is easy to understand how things go wrong and what I might need to do different. Another problem is that in my models with 24 to 39 foot legs at angles like 45 degrees or flatter we want to simulate from where 1/3 is in the water to where it is almost all in the water, so some "linear assumptions" like in Boundary Element Method (BEM) used in some models probably are not actually accurate enough for my needs. It is an important question/experiment to see how much these legs damp heave and roll type motions. We have a Linux computer with a NVIDIA A6000 GPU and AMD threadripper CPU with 64 cores and about 750 GB of RAM. So we could do some compulationally intensive simulations at no extra cost to us. Would be fun really to make use of this systems power. I don't care about simulating propulsion for now. It will go very slow and that is fine for a seastead. The important question at this point is how stable is a design on the waves and at what wave level might something fail. I would like a high level of engineering accuracy in the simulation. I have tried Project Chrono and think that BEM is not accurate enough for my unusual shaped models. This only took a couple days of spare time to get working, with the help of Claude Code. I hear Chrono::FSI-SPH might be better for my needs. If we use this then Chrono is not using BEM? Capytaine and MoorDyn is another recommendation. Both of these can be used from Python. Claude Code and Cursor.ai can help me with Python scripts so it might go fast. I was told that Blender can be used but that the physics simulations are not at all accurate. Is that still true or has someone made something so I could do a reasonably accurate simulation of a simple seastead model using blender? And Claude Code or Cursor.ai could help me with this? I was told maybe using WEC-Sim and MoorDyn could work. Does this seem like a good way to go? Would these let me make videos showing how a seastead design would work in the ocean? Could WEC-Sim and MoorDyn handle this sort of thing? It seems this needs MATLAB which is not free (please estimate cost for a non-student in Anguilla). Also seems this requites "Simulink" add-on and "Simscape Multibody" so there is a high total cost. Really this should not be on my list of open source solutions. DualSPHysics is another one mentioned. For this they recommend a system with a good GPU but we have one. How hard is this to use? OpenFOAM is another one that can make use of our compute cycles. Is there any other free software that might be a better way to simulate, test, and visualize my seastead design ideas? I like Claude Code and it has been a big help in setting up projects like this in the past so I am not to worried about something that may take some effort to get to first simulation. Please compare the different free software options (not just those listed above). Try to estimate how long it would take to get a simulating working in each (assume we have Claude Code helping). Try to find a link to a youtube video of a simulation in waves for each. Estimate how accurate it would be for a seastead design with several solid cylinders with pivot points and cables in waves. I generally like Linux but we have Windows machines we can use if needed. Also, after we get a simulation working for one seastead model design, how hard will it be to get another simulation running for a different model type? It will be similar that it is cylinders and cubes and cables, just different sizes and configuration of these things.