Learn/Drafting/2D Sketch Editor
Constraints & Driving Dimensions
Updated v2.3.5At a glance
- Dimensions drive the sketch the moment you place them — placing one never moves your geometry
- Constraint toolbar and Shift-hotkeys apply or remove any relationship in one click
- Live degrees-of-freedom readout; over-constraining degrades to a reference dimension, not an error
- Right-click any constraint glyph or dimension to delete it; fillets auto-constrain with tangency and radius
- Slots auto-constrain so a single dimension resizes them
Sketch constraints work the way Fusion 360 / Inventor / Onshape users expect. Every dimension you place immediately drives its value, locking the geometry at its current size — so placing a dimension never moves anything, it just holds it. Double-click to type a new value and the geometry follows; delete the dimension and its constraint is released.
Solver behavior
The solver distinguishes genuine conflicts from harmless shared corners, so normal closed profiles
never report false "over-constrained" errors. If a new dimension is already implied by everything
else, it's added as a reference dimension — shown in parentheses like ( 5.000" ) — with a
brief toast. Any solve that would collapse a line, pop a corner apart, or explode an arc's radius
is rejected rather than applied: the solver will never mangle your geometry.
Fillets and holes
Fillets are pinned with arc-line tangency, coincident endpoints, and a radius constraint, and get an editable radius dimension automatically — driving a neighboring edge keeps the fillet a fillet. A linear dimension from an edge to a circle's center drives the true perpendicular distance, so two edge-to-center dimensions position a hole exactly where you typed.