Parameters and expressions

Every dimension and feature input is a model parameter (d1, d2, …). User parameters are ones you add yourself, with a unit, an expression and an optional comment. Change them in Change Parameters (parameters.change). The timeline rebuilds from the first feature that uses them.

In the SOLID toolbar’s CONFIGURE panel, click Parameters to open the user and model parameter editor. The separate Configurations button opens the configuration table; Configure remains in the dropdown for configuring columns.

Press Enter in the new parameter’s name, expression or comment field to add it. Valid entries return focus to the name field for the next parameter; invalid entries remain editable. In expression fields, Up/Down selects an autocomplete suggestion, Enter/Tab accepts it, and Escape dismisses the suggestions. Accepting a suggestion does not also submit the parameter.

Expressions are unit-aware: 2 * width + 5 mm, angle / 2, sqrt(area), 1 in + 3 mm, using + - * / ^, parentheses, sin cos tan asin acos atan atan2 sqrt abs min max floor ceil round mod trunc and unit conversion. A length where an angle is expected (or the other way round) is an error, not a silent conversion. Cycles are reported with their path (a → b → a), renaming a parameter updates every expression, dimension and feature input that uses it, and a parameter in use can’t be deleted (the error lists its users).

The design’s units (Document Settings in the browser: mm, cm, m, in or ft) set how a bare number typed into a feature is read. In an inch design 2 means 2 in. Changing the units never moves existing geometry.

Parameters export to and import from CSV or JSON (parameters.export, parameters.import). Configurations (config.*) keep a table of rows, each with its own parameter values and suppressed features, physical materials and body appearances, switched with config.activate. The table’s Library picker selects material or appearance values. Choose Follow material to clear an appearance override. Custom looks retain their colour and opacity across activation, undo and save/reopen. See configuration commands and examples.