Profiles and fullness

Shape the sail’s horizontal sections one height at a time, or use Fullness to make every interior section deeper or flatter together.

Keep the four shape layers separate

Layer	Primary controls	What it changes
Edge shape	Round, Opening, Position	The luff, foot, and leech outline and out-of-plane bow
Section profile	Depth, Draft, Entry, Exit	One horizontal cross-section of the sail
Whole-sail fullness	Fullness	Every interior section’s Depth by the same multiplier
Mould loft	Mould algorithm, smoothing, foot stretch	How the section curves become one continuous surface

This page owns section profiles and whole-sail fullness. See Edge shape and twist and Mould controls for the other two layers.

A profile shapes one horizontal section. Fullness scales the Depth of all interior profiles together.

Edit a section in Profile Edit

1. Switch the Shape card to Profile Edit

   Select Profile Edit at the top of the right-hand Shape card. The sail displays selectable section lines.

2. Select a height

   Click a section line on the sail or choose a chip under Heights. The foot chip is always present. The 100% head boundary is not shown as an editable profile height.

   New designs normally start with interior heights at 10%, 25%, 50%, and 75%. A new Code 0 starts at 25%, 50%, and 75% instead.

   Checkpoint

   The chosen chip is highlighted and the card heading changes to Foot or H = …%.

3. Adjust the selected section

   Use Depth for the amount of camber and Draft for the chordwise position of that camber. The second ± slider makes a fine Depth adjustment around the coarse value.

   For an interior height, Depth runs from 0–50% in 0.5% coarse steps. The fine slider runs from −1.5 to +1.5 in 0.1 steps. Draft runs from 10–90% in whole-percent steps.

4. Choose the section algorithm

   All current sail types start with Two-quadratic (NACA), but you can switch either way at any time:

   Choice	Controls in Profile Edit	Range	Observable difference
   Two-quadratic (NACA)	Entry, Exit	5–95%	The maximum Depth and Draft position are held directly; Entry and Exit change the two sides of the section
   Cubic Bézier	Entry, Exit	0–89°	Entry and exit tangent angles shape a softer single curve; its deepest point can shift from the requested Draft position

   With Two-quadratic selected, the full Sail Shape table calls the same shape controls Luff round (%) and Leech round (%). Profile Edit presents them as Entry and Exit so moving right has the same “sharper entry” direction as Cubic Bézier.

1234

Profile Edit on the preloaded Albin Vega 27 gennaker example, with H = 50% selected.

1. 1 Selected section on the sail
2. 2 Height chips
3. 3 Section algorithm
4. 4 Selected-section controls

Shape the foot profile

The foot chip deliberately uses its controls differently because the foot is an edge, not an interior horizontal section:

Foot control	Range	Same setting elsewhere
Depth	0–20% plus the same ±1.5 fine control	Foot > Opening (%) in Design > Sail Shape > Edge curves
Draft	30–50%	Foot position (%) on the Preview card and Position (%) in Sail Shape

The foot does not show algorithm-specific Entry or Exit controls. Changing the profile algorithm still changes the curve form used for the foot.

Add, remove, and reset heights

Add an interior height

Select + Add, enter a value below 100%, and confirm the prompt. The foot already owns 0%, so a new interior height must be above 0%. Duplicate and out-of-range values are ignored. The new height starts from values interpolated between its neighbours and becomes selected.

Remove a height

Select an interior chip, then use Remove H = …%. The foot cannot be removed, and the button disappears once only two chips remain.

Reset one height

For an interior height, Reset restores the canonical value for that height. The common 25%, 50%, and 75% depths are 16%, 20%, and 18%; their Draft positions are 44%, 43%, and 42%. Cubic Bézier Entry/Exit reset to 50°/30°; Two-quadratic Entry/Exit reset to 50%/50%.

Reset the Profile Edit pane

The pane-wide Defaults button:

• selects Two-quadratic (NACA);
• rebuilds the base interior height list as 25%, 50%, and 75%;
• restores the depth and draft values listed above;
• restores the algorithm-specific profile values; and
• clears Lock fullness.

The currently selected interior height is reset too, so a selected custom height remains alongside 25%, 50%, and 75%. These are shared Profile Edit defaults. They do not recreate the chosen sail type’s File > New profile—for example, an unselected 10% height used by most new sail types is removed.

The Preview pane has a different Defaults action for edge shape, head twist, and Fullness. Its exact reset values are listed under Reset the Preview shape controls.

Use the full Sail Shape table

Open Design > Sail Shape when entering several exact values is quicker than selecting sections on the canvas.

Profile Edit card	Design > Sail Shape > Profile points
Selects one section line or chip	Shows all known heights as table rows
Shows the foot as a dedicated chip and hides 100%	Can display any 0–100% rows present in the profile arrays
Adds a height below 100% and selects it	+ Height accepts 0–100% and adds the fields used by the selected algorithm
Protects the foot and stops at two total chips	A row can be removed until two table rows remain
Provides coarse and fine Depth sliders	Provides exact number inputs only
Owns Lock fullness, per-height Reset, and pane Defaults	Has no profile reset or fullness lock control

Both surfaces edit the same design. Done closes the Sail Shape dialog; changes were already visible while it was open.

Scale every section with Fullness

The Fullness slider is in Preview mode on the Shape card.

• Centre is 1.00× and leaves the profile unchanged.
• Full left is 0.50× and halves every interior Depth value.
• Full right is normally 2.00× and doubles every interior Depth value.
• The right end shortens automatically if doubling would push any Depth above 50%.
• The ↺ control returns the multiplier to 1.00×.

Fullness changes Depth only. It preserves the relative top-to-bottom depth distribution and does not scale Draft, Entry, Exit, edge round, opening, or mould controls.

Protect hand-tuned depths

Turn on Lock fullness in Profile Edit. Preview continues to show the Fullness control, but it reads locked, is disabled, and applies a neutral multiplier. Return to Profile Edit to unlock it.

When you save, the current multiplier is folded into the saved Depth values and the live slider returns to 1.00×. The lock itself is saved with the design.

Symmetric spinnaker constraints

When the active sail type is Symmetric spinnaker, the shape cards and Sail Shape dialog enforce these constraints:

• interior Draft and foot Draft/position stay at 50%;
• Cubic Bézier shows one combined Entry / Exit control and mirrors the two angles;
• Two-quadratic shows one combined Entry / Exit control and mirrors the two sides of the section;
• the luff and leech edge-shape controls move together; and
• Head twist stays at 0°.

Current editor boundary

The separate leech chord remains editable in Design > Sail Shape, so the dialog does not enforce equal luff and leech chord lengths. The section-detail controls shown after switching the main canvas to 2-D also do not apply the symmetric locks. Use the Profile Edit card for symmetric section changes and check both edge lengths before generating panels.

Continue to the mould

After the section curves look right, choose how they become one surface in Mould controls.