Numbers and units
Every dimension is stored in millimetres. Number fields accept arithmetic and unit suffixes, and you can change a value by dragging as well as by typing.
Typing a value
Any length field accepts ordinary arithmetic: +, -, *, / and brackets.
| You type | Result |
|---|---|
(30 - 2*3) / 2 | 12 mm |
25.4/2 | 12.7 mm |
1 in | 25.4 mm |
40 mm | 40 mm |
A number with no suffix is read in the unit you are working in. A suffix applies to the whole expression and overrides it: mm, cm, m, in (or ") and ft (or ') are understood. Typing a unit converts the value; it does not change the units you are working in.
Angle fields take degrees. A bare number is degrees, and deg or ° may be added. A length unit typed into an angle field is refused.
A value outside a field's permitted range is refused with an explanation. It is never quietly rounded or clamped. A number whose punctuation could mean two things, such as 1,234, is refused rather than guessed at: write it with a single decimal separator and no thousands separator.
Dragging a value
Press the label beside a field and move sideways to scrub the value. The model updates as you drag, and the whole drag is a single undo step.
| While dragging | Effect |
|---|---|
| ⇧ | A tenth of the normal rate |
| ⌥ | Five times the normal rate |
| Esc | Stops the drag and returns the value to where it started |
Changing modifier mid-drag changes the rate, never the value already reached.
Stepping a value
Click into a field and − and + buttons appear beside it, each moving the value by one step.
Display units
You choose which units values are shown and typed in. This never resizes a body.
- App Settings ▸ Default Units sets the measurement system for every project: follow your Mac's measurement settings, or choose a unit. Millimetres, centimetres, metres, inches and feet are available, with a choice of decimal places.
- File ▸ Project Settings… can give one project its own units instead. Turn off Use app defaults and choose a length unit. The choice is saved in the project and can be undone like any other edit.
The status bar always shows the unit currently in use.
Circles are shown and entered as a diameter by default. Turn off Enter circles as diameter in App Settings ▸ Display to work with radii instead.