My method for entering a table of offsets as points into Rhino: Table of Offsets into Rhino as 3D Points
My approach to fairing a set of hull lines is to create a “virtual half model” surface based on the table of offset points. The virtual half model is then adjusted/faired until I’m satisfied with the combination of the fairness and the deviation from table of offsets. A revised set of lines and offsets can be created from the virtual half model.
General approach to using a table of offsets:
@bigjimslade I assume you are describing fairing a set of boat/ship “lines” starting with a table of offsets.
My approach is to first find the “typos”. I import the offset points and then create the curves using CurveThroughPt on the points for each waterline, buttock, sheer, rabbet, etc. I carefully look at the curves for the points which are obviously off, look at the corresponding offset, and usually can figure out that 1-7-6 should have been 1-6-6 or that 2-3-1 should have been 2-3-7 or sim…
One approach:
Create a set of edge curves. First create polylines around the boundary from the input points on the edges. Use FitCrv to obtain a NURBS curve from the polyline. The polyline is used as the input to FitCrv because “When the input to the FitCrv command is a polyline, the FitCrv command treats the polyline vertices as a list of points, and it tries to compute a curve that goes near the points but has a reasonable number of control points. The FitCrv command is meant for polylines wi…
Approach used to create the virtual half model:
Below is a brief description of the method I use for creating a hull surface from offsets using Rhino.
Import the offsets into Rhino as coordinate triplets to create a set of points.
Create curves the points using CurveThroughPts with Knots=Chord. If any curves have kinks, for instance where they cross a chine, create separate curves for each segment between kinks.
Look for large, obvious errors in the point locations, correct those and generate corrected curves. I do not spend a lot o…
Modeling hulls with stems which smoothly transition into the keel"
Round bottom boat hulls frequently have stems which curve smoothly into the keel. A NURBS surface with four sides is not a simple fit to such a shape.
[Curved Stem Lines 1]
I know of three methods to model such a hull side using a single NURBS surface on each side. Each has advantages and disadvantages. A Rhino .3dm file with an example of each method is attached. BowCurve11.3dm (350.3 KB) The surfaces are very close to each other in shape. Note that the orange curves are isolines but do not …