Sketching

Starting a sketch

• Press S (or the Sketch button), then click an origin plane or any flat face.
• Or select a flat face first, then press S.
• Or click a plane under Origin in the browser.

The camera turns to face the sketch plane, the grid moves onto it and bodies become see-through.

Sketch plane frame:

Plane	X direction	Y direction	Normal
XY	world X	world Y	+Z
XZ	world X	world Z	−Y
YZ	world Y	world Z	+X
A flat face	world X projected onto the face (or horizontal on walls)	perpendicular to X in the face	the face's outward normal

On a face, the sketch origin is the world origin projected onto the face's plane. It doesn't move when the face changes shape. Any sketch can be offset along its normal (the Plane offset field).

Drawing tools

Every tool works with two clicks or press, drag, release. While drawing, start typing a number to enter an exact size; Tab moves to the second size, Enter places the shape, Esc cancels.

Tool	Key	Input	Typed sizes	Editable fields
Line (outline)	L	Click each point; click the first point (or press Enter) to close; Backspace removes the last point	Length, then angle	Points; Smooth curve; Round corners
Rectangle	R	Two opposite corners	Width, Height	Width, Height, X, Y, Position from (Corner/Center), Rounded corners, Rotation
Circle	C	Centre, then radius	Diameter	Diameter, Centre X, Y
Ellipse	E	Centre, then a corner of its bounding box	X radius, Y radius	Radius X, Radius Y, Centre, Rotation
Polygon	P	Centre, then a corner (default 6 sides)	Radius	Radius, Sides (3–64), Centre, Rotation
Slot	O	Centre of first end, then second end	Length, angle	Length, Width, Centre, Rotation
Text	T	One click where the text starts; the text box in the panel takes focus		Text, Size, Rotation, X, Y, Bold
Gear	G	Centre, then drag the size (teeth = pitch diameter ÷ module, module 2)	Pitch diameter	Teeth (6–200), Module, Bore Ø, Centre
Select	V	Click a shape to select; drag to move it

Text uses IBM Plex Sans (regular or bold). Its outline in the sketch is a dashed box; the real letters show in the shaded fill.

Gears are involute spur gears with a 20° pressure angle and standard proportions (addendum 1 × module, dedendum 1.25 × module). Two gears mesh when they share a module; their centre distance is module × (teeth A + teeth B) ÷ 2.

Outlines: Smooth curve draws a closed spline through the points. Round corners rounds every corner with one radius.

Snapping

• Snaps to endpoints, midpoints, centres, the origin and the grid (half the grid spacing).
• Horizontal and vertical alignment guides appear when the cursor lines up with existing points.
• The snap marker's shape shows what it snapped to.
• Hold Alt to place freely, without snapping.

Solids and holes

Each shape has a Solid or hole mode:

• Automatic (default): a shape that lies inside another shape becomes a hole. Shapes that touch the outer shape's edge count as inside.
• Solid: always adds material.
• Hole: always removes material.

A gear's bore is always a hole in that gear. The shaded area in the sketch shows exactly what will become solid.

If a hole touches its outline in two separate places (which would split the shape in two), the sketch shows a warning suggesting a slightly smaller hole.

Construction shapes

X toggles construction. Construction shapes are dashed guides for snapping only; they never become solid.

Arrange tools (selected shape)

Action	Key	Result
Duplicate	Ctrl+D	Copy offset by +10, −10 and selected
Rotate 90°	Shift+R	Rotates the shape about its own centre
Mirror ↔		Mirrored copy across the sketch's vertical axis
Mirror ↕		Mirrored copy across the sketch's horizontal axis
Copies around origin		N copies evenly spaced around the sketch origin (e.g. a bolt circle)
Row → / ↑		N copies spaced by Gap along X or Y
Delete	Del	Removes the shape

These work on shapes whose positions are plain numbers. If a position comes from a formula, Whittle leaves it unchanged and explains why, so formulas are never overwritten. Dragging follows the same rule.

Finishing

Esc switches back to the Select tool; a second Esc (or Finish sketch) closes the sketch as one undo step. Cancel in the panel discards all changes. An empty new sketch is discarded automatically.