Designing and Fairing the Hull
RhinoMarine uses NURBS surfaces to define the hull shape, because this class of surfaces combines ease of fairing with the flexibility to create the shape that you want. For this reason, NURBS have become the standard modeling approach in the marine, aircraft, and auto industries, as well as industrial design and even architecture.
In the RhinoMarine environment, the user can quickly generate the initial hull surface in a number of ways:
- Hull Design Wizards for sailboat and hard chine hulls
- Lofting a surface through cross sections (such as stations)
- Scaling an existing hull model
- "Sculpting" the hull from a flat surface
With any of these approaches, the intent is to create a surface with a simple, orderly control net. The "control net" is the rectangular array of control points that define a surface. Once the control net has been created, the hull is modified and faired using tools such as move, scale, and rotate.
RhinoMarine adds a number of tools to Rhino's already very capable interface to make this process easier for the naval architect.
- Sections: Define the locations of stations, buttock, waterlines, cants, inclines, and diagonals through the hull, and watch them update dynamically as you modify the surface
- Constraint planes, which allow the user to easily specify the construction plane for editing. This makes it particularly easy to edit in the Perspective view
- Control net toggle: turns the control net on or off for all surfaces, saving the step of selecting the surface first (as is necessary with Rhino's control net on/off toggle)
- Corner wrap: Automatically enforce slope and curvature continuity in the forefoot of the hull, as it transitions from the stem to the bottom
- Create plate: Simple interface to create a flat surface, allowing the user to specify the dimensions, location, degree, and number of rows and columns in the surface.
Rhino has a number of tools for evaluating the fairness of a surface, including surface curvature (Gaussian, mean, minimum, and maximum), zebra striping, and of curvature graphs on individual sections.
