Sometimes we are asked if an Orca3D hull model can have a bulbous bow, even though the Hull Assistant does not include a bulb.
It's important to realize that the Hull Assistants are a quick way to create a hull surface that is close to your target shape, giving you a head start in your modeling. Once the hull is created, it's a NURBS surface like any other. Orca3D's modeling and analysis tools don't know (or care) if the NURBS surface was created with a Hull Assistant, created using standard Rhino tools, or even imported from other NURBS-based programs.
While the Assistant does not create a bulb, nothing prevents you from adding a bulb. This could be done with a separate surface that is blended into the main hull surface, or by adding extra control points to the hull surface and “pulling” the bulb shape out of the bow. The best approach really depends on the shape of the bulb. If it’s a cylindrical bulb, the former approach is probably better. Some other types of bulbs are more integral to the hull shape, and the second approach might work better.
In either case, hydrostatics and other analysis tools will function properly. If you create the bulb with a separate surface, be sure to trim both the bulb surface and the hull surface against each other, so that you can “see into” the bulb; see the images below.
