Transforming and Duplicating Sketch Geometry

Once a sketch has more than a few entities, redrawing similar geometry by hand gets tedious and error-prone — and it's easy to lose track of relationships between the pieces. The five tools in this chapter operate on geometry you've already drawn and already selected: they copy it, move it, resize it, or reflect it, instead of asking you to draw it again.

Prerequisites

Before you begin, ensure that:

• You've completed Cleaning Up Sketches and have some sketch geometry to work with — a handful of lines or a simple shape is enough to practice on.

Finding These Tools

These five share one toolbar button and drop-down, the same pattern as the modify tools from Cleaning Up Sketches. Only Mirror has a keyboard shortcut; Translate, Rotate, Scale, and Symmetry are reachable only through the drop-down.

Move or copy — the C toggle

Translate, Rotate and Scale each do double duty. While one is active, the status prompt shows the current mode and the keys that change it:

2 selected — [Point-to-Point mode, Copy — M: mode, C: move/copy, +/-: copies] click base point

• C toggles between Copy (leave the originals, add duplicates) and Move (reposition the originals). All three tools start in Copy, so the prompt reads Copy the moment you activate one — you press C to get Move, not the other way round.
• + / - set how many copies to make, up to 200 — each one offset by another step of the same transform. This is how you stamp out an evenly spaced row. The up and down arrow keys do the same thing, if they're easier to reach.
• M cycles the mode: Translate offers Point-to-Point, Delta X/Y, Direction+Distance, and Along Line.

So "creates offset copies" is the default behaviour, and C is how you turn copying off.

Note

These keys only do anything while a transform tool is actually running — they belong to the tool's prompt, not to the drawing. Outside a transform, C starts the Circle tool and M starts Mirror.

That last column matters: every tool here except Symmetry copies — your original geometry stays exactly where it was, and new entities appear alongside it. Symmetry is the exception; it repositions the entities you already have, with nothing left behind at the old location.

Note

Mirror is the only tool in this group with a shortcut. Translate, Rotate, Scale and Symmetry are reached from the drop-down, or by name with Ctrl+Shift+P.

Selecting Before You Transform

Translate, Rotate, Scale, and Symmetry all read your current selection the moment you activate them — so select the entities you want to transform with the Select tool first, then open the tool from the drop-down. Mirror is more flexible: if you already have a selection when you activate it, it adopts that; otherwise it lets you click to build a selection afterward.

What these tools can transform

This is the limitation most likely to catch you out, because it fails quietly. The transforms handle:

Points · Lines · Circles · Arcs · Splines (both kinds) · Conic Segments · Five-Point Conics

Ordinary geometry you've toggled to construction with G counts as a line and transforms normally.

Everything else in the selection is skipped without a message — no preview, no copy, no error:

So if you select a slot, run Translate, click a base point and a destination, and nothing appears — this is why. Nothing has gone wrong and nothing was lost; the tool simply had nothing it could act on.

Note: Symmetry handles less than the others

Symmetry covers points, lines, circles and arcs only. Splines and conics, which Mirror will reflect, are skipped by Symmetry. If you need to reflect a spline in place, use Mirror with Replace Original (R) instead.

Tip: work around it by rebuilding, not by transforming

A slot or a polygon is quicker to redraw at the new location — both are two or three clicks — than to work around. A centreline can be redrawn the same way. For an ellipse you need in several places, draw it once and use its tool again rather than copying.

Mirror

Reflects the selected entities across an axis line, creating new copies on the other side.

Steps

1. Select the entities you want to mirror (or skip this and let Mirror prompt you after activating).
2. Activate Mirror (M, or via the drop-down).
3. Click any existing line to use as the mirror axis — it can't be one of the entities you're mirroring.

Result

Reflected copies appear across the axis immediately on that click — there's no separate confirm step. Mirror also links each original/copy pair with a Symmetric constraint, so if you later move one, its mirrored partner follows.

Tip

Press Escape before clicking an axis to cancel an in-flight Mirror and clear the entity selection without creating anything.

Two toggles in the prompt

While Mirror is running, the prompt ends with its current state — [R: Keep Original, D: Dynamic off] — and both letters are live:

• R switches between Keep Original and Replace Original. Replace Original reflects the selection in place instead of copying it, which is close to what Symmetry does from its own toolbar entry.
• D toggles Dynamic Mirror, which is about repeating the operation rather than about constraints. With it off, Mirror finishes on the axis click. With it on, the axis you click is locked, and every entity you click afterwards is mirrored across it immediately — one click per entity, no re-picking the axis. Press Escape to release it.

The prompt always shows which way each is set, so read it before clicking the axis rather than undoing afterwards.

Note: the Symmetric link is always on

A Keep-Original mirror always joins each original/copy pair with a Symmetric constraint. There is no toggle for it — D does not control this, and nothing else does either. If you want an unlinked copy, use Translate in copy mode instead, or delete the Symmetric constraints afterwards.

Translate

Creates a copy of the selected entities, offset by a vector you define with two clicks.

Steps

1. Select the entities to copy.
2. Activate Translate from the drop-down.
3. Click a base point — this doesn't have to be on the geometry itself, any point in the sketch works.
4. Click a destination point. The offset is the vector between the two clicks, and a copy of your selection appears shifted by exactly that amount.

Rotate

Creates a copy of the selected entities, rotated around a centre point by an angle.

Steps

1. Select the entities to copy.
2. Activate Rotate from the drop-down.
3. Click the rotation centre.
4. Set the angle. The prompt reads "Enter rotation angle, or click to set it", and an Aabs field appears on the canvas — type a value and press Enter, or move the mouse and click. Aabs is the absolute angle, measured the same way as the on-screen 0–360° readout, not a relative amount.

Rotate has three modes, and M cycles them

The above is Centre+Angle, the default. Pressing M while the tool is active switches to:

• Three-Point — click the pivot, then a start-arm point to set the zero-angle reference, then an end-arm point. The angle swept between the two arms becomes the rotation.
• Align Direction — click a target-direction point, and the selection is rotated to line up with it.

The mode is shown in the prompt while the tool is running, so check there if a click doesn't do what you expected.

Snapping the angle with S

Rotate's prompt ends with snap off by default. Press S to cycle through the increments:

off → 1° → 5° → 15° → 30° → 45° → 90° → off

With a snap set, a rotation you drive by clicking lands on the nearest multiple of it — so S until the prompt reads snap 45° and a click can only give you 45°, 90°, 135° and so on. Typing an angle overrides the snap, so precise odd values are still available without turning it off.

Note: right angles keep constraints coherent

Rotating by exactly 90° or 270° swaps the Horizontal and Vertical constraints on any rotated lines, so a line that was horizontal becomes vertical and says so. Turning a constrained shape a quarter turn leaves it constrained the way you'd expect, rather than carrying stale relations.

Scale

Creates a copy of the selected entities, resized around a base point by a factor you define with two more clicks.

Steps

1. Select the entities to copy.
2. Activate Scale from the drop-down.
3. Click a base point — the fixed point the scaling happens relative to.
4. Click a reference point. The distance from the base point to this click becomes your reference distance (1.0×).
5. Click a scale point. The ratio of (base-to-scale-point distance) over (base-to-reference-point distance) becomes the scale factor, and a copy appears resized by that amount. You can also type a factor instead of clicking — the prompt at this step reads "Click scale point (distance / ref = scale factor), or type a factor".

Scale has a second mode: M switches to Affinity

The steps above are Uniform, the default — one factor applied in every direction. Pressing M switches to Affinity, which takes separate X and Y factors.

Affinity is shorter by a click: base point, reference point, then type the two factors. There's no third click, because two independent factors can't be read off one cursor position.

Use it to stretch a shape along one axis only — 2 and 1 doubles the width and leaves the height alone. Be aware that non-uniform scaling changes what some geometry is: a scaled circle comes out as an ellipse, because a circle stretched on one axis isn't a circle any more.

Tip

If you want a precise factor like exactly 2× rather than eyeballing it, click your reference point at a snap-friendly, easy-to-measure distance from the base (along an existing edge, for instance) so the ratio is easy to place accurately by eye. Or just type the factor at the last step — the F field accepts it directly.

Symmetry

Reflects the selected entities across an axis line — but unlike Mirror, it moves them there instead of leaving copies behind.

Steps

1. Select the entities to reposition.
2. Activate Symmetry from the drop-down.
3. Click an axis line. The selected entities move to their mirrored position across that line, in place.

Note

Use Mirror when you want both the original and a reflected copy. Use Symmetry when you only want the reflected result and don't need the original geometry to stick around.

Next Steps

You now know how to:

• Tell copying transforms (Mirror, Translate, Rotate, Scale) apart from the in-place Symmetry tool
• Select geometry before activating a transform tool
• Use each tool's specific click sequence to define the transform precisely

The next chapter rounds out the sketcher by covering the remaining drawing tools you haven't used yet — polygons, slots, splines, and several more specialized shapes.

Next: Expanding Your Shape Vocabulary