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.Stem wrapper top edge.Use the DupEdge command on the bottom of the stem wrapper to create a very smallcurve.Delete the temporary stem wrapper.Rebuild the curves you just created.Select these curves and use the Loft command to create a new stem wrapper.You can check the fairness of this surface by drawing a few horizontal lines in theprofile and projecting them to the hull and stem wrapper surfaces.The joint betweenthe resulting waterlines should be extremely smooth.Stem wrapper lofted to upper edge.Draw a line in the plan view from the port rabbet at the bottom of the forefoot to apoint beyond the starboard rabbet (be sure to activate Ortho and Planar beforedrawing this curve, and deactivate object snaps before making the second pick).Draw a horizontal line for the aft edge of the forefoot and trim to the rabbet.221Rhino Marine: Motor Yacht HullTrim this line to the starboard rabbet.You should now have a horizontal line at the bottom of the forefoot.The exact locationalong the rabbet of this line is not critical.Use the NetworkSrf command to create the surface between the two halves of thehull at the forefoot.Select the port and starboard rabbet surface edges, the bottom of the stem wrappersurface and the curve you just drew.This surface will transition smoothly from the full roundness of the stem wrapper tothe flat sections of the keel flat.Use NetworkSrf to create the forefoot.Use the EdgeSrf command to create a flat surface between the two halves thatextends from the aft end of the forefoot all the way to the aft end of the hull.Join all the surfaces and check for naked edges.Keel flat, forefoot, and stem wrapper joined.Once you have performed this check and corrected any naked edges, create a planeon centerline that extends from above and forward of the hull to a point below and aftof the hull.Use this plane to trim the starboard half of the hull away.Since you will be doing work that applies to both halves of the hull, it pays not to haveto do it twice.Having only half of the hull present will simplify future modeling tasks.Once you have trimmed away the starboard half of the hull, explode the remainingsurface, since you will be doing some trimming to the remaining surfaces.Trimmingsurfaces is easier than trimming polysurfaces because surfaces can be trimmed withcurves and polysurfaces cannot.222Rhino Marine: Motor Yacht HullTrim the aft sheerNow that the hull surface has been faired, the sheer aft needs attention.Initially, youextended the upper sheer from station 5 to the transom to become one continuousedge.It is now time to trim in the transom, swim step, and sheer break from station 5aft.Turn on layer cEdges.As in most trimming operations, it will probably be necessary to extend the cuttingedges beyond the edges of the surface being trimmed.This ensures the cutting edgewill intersect the surface edge at both ends and result in a more reliable trimmingoperation.With the swim step extended aft of the transom and aft sheer transition curveextended above the sheer, in the Front viewport, trim the hull surface as shown.Trim the hull to the profile curves aft.After trimming, join the hull surfaces back together.Create the swim step transom chine and trim the hullThe intersection of the swim step transom with the hull will generate a chine.Sincethis is a visible curve, it is important that it be smooth.For this reason and becausethe surface it bounds must meet the hull tangentially, it will be done iteratively.The first step is to use the DupEdge command to duplicate the edge of the hullsurface representing the swim step side.Duplicate swim step side.In the Top viewport, use the ProjectToCPlane command to project the curve to theconstruction plane.The reason for not using the designer s swim step transom corner is that you mayhave tweaked the surface s points in this area.If so, the fillet supplied by the designerwill no longer meet the surface tangentially.223Rhino Marine: Motor Yacht HullTrim away the designer s transom plane curve.Projected side curve.Fillet or Blend the remaining curves to ensure tangency.Designer's transom blended to the projected swim step side curve.If the flexibility of your situation allows, consider using Blend, instead of Fillet.Blendlets you draw a curve that is curvature continuous, instead of being just tangent.Ifyou can prevail on the designer to allow this type of substitution, the project willbenefit from the difference.In the Top viewport, project the swim step transom corner and swim step aft edge tothe hull surface.Swim step transom corner and aft edge projected to hull.Inspect the result in profile and body plan.If the curve is not satisfactory, tweak its control points until it is smooth.Then use theProjectToCPlane command to project it to the construction plane of the view inwhich it is most unfair.Tweak the points (except the end points) in that view and project it back to thesurface again [ Pobierz całość w formacie PDF ]