Using References

Reference geometry exists to be pointed at. A plane is somewhere to sketch, an axis is something to turn or sweep around, a point is a spot to mate to. Build them deliberately and the model stops depending on faces that move.

What takes a reference

• A sketch. Start Create sketch and click the plane itself: a reference plane is one of the surfaces the sketch picker hits now, alongside the three origin squares and the faces of the part, and it wins wherever it is in front of the solid at that pixel. Selecting the plane on its own and reaching for the toolbar still works too.
• A revolve, a sweep, a helical sweep. All three ask for an axis, and a reference axis is one of the three things their picker accepts.
• A mirror, a pattern, a clearance cut. Each wants a plane or a direction.
• A Transform step. Most of the positioning steps take a point, an axis or a plane, and a reference is always a valid answer.

Anchor to references, not to faces

This is the habit that separates a model you can edit from one you rebuild.

A face of the model exists because of the features before it. Change one of those and the face may move, tilt, split or stop existing, and everything pointed at it goes with it. A reference plane built from three vertices, or an axis built from a cylinder, is one step away from the same fate but usually survives what a face does not.

A reference does not even need a body. A plane can be offset or hinged off another reference plane, or off one of the three world base planes, so a whole scaffold of datums can exist before the first extrude does. The only ordering rule is that a reference is built on something earlier in the timeline than itself.

The practical version: when a feature asks for an axis or a plane and you find yourself hunting for a face that happens to be in the right place, make the reference instead. It costs one step now and saves the rebuild later.

Hiding, disabling, renaming

The References window sits beside Sketches on the right edge, in model mode. It lists every plane, axis and point in the document, one section per kind, in timeline order. Each row carries a colour swatch, an eye, a pencil and a trash button, and clicking the name selects that reference in 3D — which is also what makes the toolbar start offering the tools that consume it.

Visible is the eye on the row, the same switch that sits in each reference's own panel, and V from the keyboard with exactly one reference selected. Off means not drawn and not clickable. Everything built on it keeps working.

Colour is per reference. Planes are cyan by default, axes magenta, points amber; the swatch opens a palette and the viewport draws whatever you pick. It is display only — no evaluation, no export and no rebuild changes with it.

Disable, from the timeline step's menu, is a different thing: the reference stops evaluating, and anything that used it fails with A referenced feature is suppressed. Use it to test whether something still depends on a reference.

Rename with the pencil on the row, which edits the name in place. There is a Rename entry in the right-click menu that opens nothing, so use the window.

Deleting one

Deleting a reference asks first, and lists what goes with it. That list covers sketches built on the plane, and their extrudes, other references built from this one, and every revolve, sweep, helical sweep, pattern, mirror and Transform step that named it. The trash button on the row asks the same question.

See also

• Reference Planes: making the one you will use most
• Reference Axes and Points: lines and spots to aim at
• Transform Basics: where most references end up being used