Create vertical trimming lines
1 Make the Temp layer current and turn on the Camber Crv layer.
2 Start the Line command.
3 At the Start of line … prompt, use the End object snap to pick a point at the starboard corner of the transom at the sheer.
4 At the End of line prompt, in the Right viewport, pick a point approximately 6 feet above the transom corner.
5 Select the vertical line you just created.
6 Start the Copy command.
7 At the Point to copy from … prompt, use the End object snap to pick the lower endpoint (at the sheer) of the vertical line you just created.
8 At the Point to copy to prompt, use the Near object snap to pick four evenly spaced points along the starboard sheer.
Deck construction lines.
Mirror the vertical lines across centerline 1 Select the vertical lines you just created.
2 Start the Mirror command.
3 In the Right viewport, at the Start of mirror plane … prompt, type 0.
4 At the End of mirror plane … prompt, use Ortho to drag the mirror plane line up along the z-axis.
Make copies of the camber curve 1 Select the camber curve.
2 Start the Copy command.
3 At the Point to copy from … prompt, in the Right viewport, pick a point.
4 At the Point to copy to prompt, use Ortho to pick 5 points directly above or below the origin point you just picked.
The copies of the camber curve being created should cross the vertical lines previously created.
5 Select all of the temporary deck beams you just created and use the ChangeLayer command to change their layer Dk Beams Temp.
One camber curve copy for each construction line.
Trim copies of the camber curve to match the beam at each vertical line 1 In the Right viewport, select one of the vertical lines on the starboard side and
3 At the Select object to trim … prompt, pick the outboard end of one of the camber curves on the starboard side and the outboard end of the same camber curve on the port side.
4 Repeat these steps for each of the camber curves.
Each of the curves thus created will be a temporary deck beam to enable creation of the deck centerline.
Move the temporary deck beams into place on the sheer 1 Select one of the temporary deck beams.
2 Start the Move command.
3 At the Point to move from … prompt, use the End object snap to pick a point on the end of the selected temporary deck beam.
Do not pick a point on the vertical line.
4 At the Point to move to prompt, use the End object snap to pick the endpoint of the corresponding vertical line where it meets the sheer.
Do not pick a point on the sheer.
5 Delete the two vertical lines associated with the temporary deck beam you just moved.
6 Repeat these steps for each of the temporary deck beams.
Temporary deck beams in place.
Draw the deck centerline
1 Start the InterpCrv command.
2 At the Start of curve … prompt, use the Mid object snap to pick a point at the midpoint of the transom sheer.
3 At the Next point of curve… prompts, use the Mid object snap to pick a point at the midpoint of each of the temporary deck beams.
4 At the Next point of curve… prompt, use the Mid object snap to pick a point at the midpoint of the upper edge of the centerline deadflat at the stemhead.
Temporary deck beams in place and deck centerline drawn through midpoints.
Extend the deck centerline 1 Turn on Planar mode.
2 Start the Extend command.
3 At the Select boundary objects … Press Enter for dynamic extend prompt, press Enter to indicate dynamic extend.
4 At the Select object to extend ( Type=Line ) prompt, in the Front viewport, pick a point near the transom on the new deck centerline.
5 At the End of extension prompt, pick a point approximately 1 foot aft of the transom.
6 Repeat these steps for the forward end of the deck centerline curve.
Copy full-breadth camber curves to the deck centerline 1 Select the temporary deck beams.
2 Select the camber curve that remains suspended above the hull.
3 Start the Copy command.
4 At the Point to copy from … prompt, use the Mid object snap to pick the midpoint of the selected camber curve.
5 At the Point to copy to prompt, use the End object snap to pick the aft end of the deck centerline.
6 At the Point to copy to prompt, use the End object snap to pick the forward end of the deck centerline.
7 At the Point to copy to prompt, use the Near object snap to pick four evenly spaced points along the deck centerline.
Loft the full-breadth deck
1 Select the full-breadth camber curves.
2 Start the Loft command.
3 In the Loft Options dialog box, click OK to accept the defaults.
Lofted deck.
4 Select the full-breadth camber curves.
5 Use the ChangeLayer command to change them to layer Dk Bms Full.
Trim the full-breadth deck to the hull 1 Select the hull.
2 Start the Trim command.
3 At the Select object to trim … prompt, select the deck outboard of the sheer.
The deck will trim to match the sheer, transom and centerline deadflat.
Join the full-breadth deck to the hull 1 Select the hull and deck.
2 Use the Join command to join the hull and deck surfaces into one polysurface.
3 Select the hull/deck polysurface.
4 Use the ShowEdges command to display any unjoined edges.
Trimmed and joined hull, transom, and deck.
Diagnostics
One final step awaits you before you can move on to calculating hydrostatics, generating a lines drawing, and accepting your accolades for a job well done. You must determine if you have any geometric problems. Rhino has several tools to tell you about bad geometry. You will use the SelBadObjects and ShowEdges commands.
With these two commands, you can determine if Rhino’s hydrostatics function as well as other third-party software will be able to work with your model. If you run these and get positive results, you can rest. Otherwise, you must seek out the culprits (usually broken edges), fix them, and rerun the commands until the results are positive.
In creating this model for the tutorial, a bad edge was encountered at the lower panel of the transom. Untrimming the panel and the hull, retrimming and rejoining everything solved the problem. As with most diagnostic procedures, there is no one answer. Each situation requires its own solution.