Free or Low Cost Hull Modeling Software

[Mike Inman]

Thanks, those are awesome designs.

As I said, it's probably more how I've been using Blender than Blender itself. OpenSCAD starts with a text editor and I just naturally approach that by starting to define variables for critical dimensions and build up the geometry from those, and, as you say, if you want an elliptical surface in OpenSCAD (not a squashed circle) you get out the equation for the ellipse and write a code-loop to draw it...

Blender starts out with that damn useless cube in the middle of a point-click-drag-drop interface and when I want Blender to do virtually anything, I Google search up a few YouTube videos which eventually show me more or less what I'm looking for - but as I said, these tend to the clay-sculpting approach. For instance: your (extremely impressive) toy tugboat drawing, after you placed the stringers, there's not a parameter in the model where you can change the overall length or beam and the stringers adjust to match, is there? If I could base my Blender renders on adjustable parameters where I might, for instance, change the interior cabin dimensions and have the exterior hull shape adjust itself to match, I'd be much more excited about spending the time developing the models.

Clearly, Blender makes the more attractive renders, but when I want to tweak and trade off parameters like cabin vs gangway width still fitting in a limited beam, it doesn't feel like I can readily do that in Blender.

 

[Dolfiman]

I think Gene-Hull can be put in this category, for early stage project :
- for sailing yacht , attached to the quote #1 of this thread :
Gene-Hull upgrade 2,3 https://www.boatdesign.net/threads/gene-hull-upgrade-2-3.60748/
Tutorial for Gene-Hull UE 2,3 https://www.boatdesign.net/threads/tutorial-for-gene-hull-ue-2-3.61498/
- for canoë, attached to the quote#58 of this thread :
Canoe length, efficiency and speed https://www.boatdesign.net/threads/canoe-length-efficiency-and-speed.61301/page-4
- for catamaran hull, attached to the quote#5 of this thread :
Gene-Hull upgrade 2,3 https://www.boatdesign.net/threads/gene-hull-upgrade-2-3.60748/

 

[Dejay]

Fusion 360 is a really amazing software with lots of powerful features and it's free for enthusiasts, students and startups <100k. But it does have an steep learning curve and doesn't support anything specific for hull modelling.

You do have subdivision meshes and nurbs and parametric objects so it's easy to make something quick and dirty to try out ideas. But working with sketches and splines to define hull forms doesn't work that well. So it's kind of hard to get exactly what you want but easy to make smooth shapes.

To use sketches and splines to loft from boat line plans is really cumbersome. You have to set up each station and waterline with a new construction plane and a new sketch and then watch out that you don't add accidental constraints to your sketch or you won't know what's happening. Maybe lofting plans using subdivision meshes works better, I have to try that.

It also has lots of cool features to set dimensions and use them for parametric designs or alter the timeline. I hoped that I could set up something like a parametric catamaran hull to try some ideas but there are lots of little hitches and a few feature missing to make that work unfortunately.

There is a lot of potential imho. It has a FEA simulation for isotropic materials. And a full CAM module for CNC and 3D printing so if you want to design or 3D print other boat parts it's just amazing.

But PolyCAD and Delftship is probably much easier for hull modelling.

 

[Anchorman_XL]

Fusion 360 is a really amazing software with lots of powerful features and it's free for enthusiasts, students and startups <100k. But it does have an steep learning curve and doesn't support anything specific for hull modelling.

You do have subdivision meshes and nurbs and parametric objects so it's easy to make something quick and dirty to try out ideas. But working with sketches and splines to define hull forms doesn't work that well. So it's kind of hard to get exactly what you want but easy to make smooth shapes.

To use sketches and splines to loft from boat line plans is really cumbersome. You have to set up each station and waterline with a new construction plane and a new sketch and then watch out that you don't add accidental constraints to your sketch or you won't know what's happening. Maybe lofting plans using subdivision meshes works better, I have to try that.

It also has lots of cool features to set dimensions and use them for parametric designs or alter the timeline. I hoped that I could set up something like a parametric catamaran hull to try some ideas but there are lots of little hitches and a few feature missing to make that work unfortunately.

There is a lot of potential imho. It has a FEA simulation for isotropic materials. And a full CAM module for CNC and 3D printing so if you want to design or 3D print other boat parts it's just amazing.

But PolyCAD and Delftship is probably much easier for hull modelling.

Fusion has only gotten better with time. Depending on the complexity of the shapes you’re making, there are some tricks you can do in order to get around the traditional lofting techniques. I made a quick model the other day with a drawing of the shape from the side and from the top, and from the bottom. Extrude basic block, slice top and bottom off, then loft from the top surface to the bottom. I was able to export one of the sides of this simple model, and import into rhino and use the command “unroll” to get a pretty good approximation of the side as a flat panel in order to cut it from a piece of plywood. I’ve been looking for a program other than rhino that can “unroll” a surface and make it flat, like peeling off the pieces of a beach ball to make a pattern, but so far, no luck finding anything else for that.

 

[baeckmo]

You can use "Meshmixer" (Free) for unwrapping. Then there is the "Boundary First Flattening" (Free); it's super quick and gives a hint on where to place relief cuts. The most accurate unwrapping is the "Mesh Unfolder" (Cheap), although a bit clumsy, but it is the only one I've seen that gives the correct shape for the flat surface to be rolled to the 3-d shape. Note that the stretching and compression will be different when wrapping a flat to 3d, compared to flattening a 3d shape! Some cad's like KeyCreator and SolidWork do unwrap, but not the reverse, and their algorithms sometimes show crazy outcomes.

 

[Anchorman_XL]

Thanks for those tips, I’ll give them a look. I’m trying to prepare for the day when I won’t have all the software a person could possibly wish for at work…