dimensions

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Annotation

Dimensions

Place dimension annotations on your drawing, choose what each one measures, restyle how they look - and export them faithfully.

A dimension is a measurement you place directly on the drawing to call out the size of something - the kind of dimension line, with extension lines and arrowheads, you'd expect on a technical drawing. It reads its measurement live and labels it with the number.

Unlike a construction, a dimension is purely an annotation: it never becomes part of your geometry and nothing you build depends on it - it's there to communicate a measurement, not to drive one. It does export, though. Dimensions come out as clean, portable geometry on their own Annotations layer, so they render the same in Illustrator and in DXF/CAD, and stay separable from the geometry itself. See Exporting SVG and Exporting DXF.

You can also build a dimension in the node graph - see Dimension: Linear, Dimension: Angle, and Dimension: Radial. A node-made dimension behaves and exports exactly like a hand-drawn one.

Three dimension tools

Dimensions are split into three dedicated tools, each in the Draw menu:

• Dimension: Linear - the straight-line distance between two points (aligned, horizontal, or vertical).
• Dimension: Angle - the angle between two edges, or across three points.
• Dimension: Radial - the radius (or diameter) of a circle or arc.

Placing a linear dimension

With Dimension: Linear, work in three clicks:

1. Click the start of the span. If there's a point there, the end latches onto it; otherwise it drops at that spot. You can also click a segment or edge instead of two free points - hover a segment and it highlights, ready to measure its length.
2. Click the end of the span, the same way.
3. Click where you want the dimension line to sit - this sets how far it floats off to the side of what it measures.

A live preview follows your cursor as you go. The finished dimension shows extension lines, the dimension line with arrowheads, and the value on a small chip, upright along the line. The number reads in your current working unit (millimeters), rounded to up to four decimal places with trailing zeros trimmed - so a clean 25 mm reads as 25, not 25.0000, while a value that needs the precision shows it. The same rule applies to a radial dimension's radius/diameter and an angular dimension's degree read-out.

Radial and Angular each have their own click sequence - see their pages.

What each dimension measures

A dimension carries a type. Which types are available depends on the tool:

Linear (from Dimension: Linear) - three types, switchable after the fact:

• Aligned (default): the straight distance between the two points, along the line that joins them.
• Horizontal: only the X span between the two points, ignoring any vertical offset.
• Vertical: only the Y span between the two points, ignoring any horizontal offset.

Because Horizontal and Vertical read a single axis, the same pair of points can give three different numbers - the aligned distance, the width, or the height.

Radial (from Dimension: Radial) - radius or diameter of a circle or arc.

Angular (from Dimension: Angle) - the minor angle (<= 180 degrees) between two edges, or its reflex explement (> 180 degrees).

Switching a dimension's type

Right-click an existing dimension to switch within its family - the measurement re-reads immediately from the same picks:

• a linear dimension -> aligned <-> horizontal <-> vertical;
• a radial dimension -> radius <-> diameter;
• an angular dimension -> minor <-> reflex angle.

The value chip and its label follow the new type. (Switching across families - say a linear into a radial - isn't a thing; pick the tool that matches what you're measuring.)

Radial placement: inside or outside

A radius dimension has two standard placements, and Locus picks between them by where you place the label:

• Place the label inside the arc and the dimension line runs from the center out to the arc, with the arrowhead on the arc pointing outward and the text sitting inside.
• Place it outside and a leader runs from outside in to the arc, the arrowhead points inward, and the text sits outside.

Drag the label across that boundary to flip between the two. A small center mark and a dashed radial guide show the geometry the radius is read from.

Live and associative

When a dimension end is latched to a point, it tracks that point. Move or scale the construction and the dimension's value updates to match - it stays honest as the design changes rather than freezing at the value it had when you drew it.

Editing

Select a dimension and grips appear. Drag the dimension line (or its ends) to change how far it floats off the measured span; drag the label to reposition it (and, on a radial, to flip inside/outside). Drag an endpoint grip onto a different point to re-target what that end measures - release over a point to latch onto it. A dimension's defining points also show in the Layers panel as reassignable rows, and a radial's target circle / an angular's two edges can be reassigned there too.

Note

Dimensions only show when View > Show Dimensions is on. That setting is remembered between sessions, alongside the grid and axes toggles.

Styling a dimension

Select a dimension and the style strip lets you restyle it like any other object:

• Color of the line, arrowheads, and number.
• Line weight: how thick the dimension line draws.
• Dash: a dashed measurement line if you want it. Only the measurement line dashes; the extension lines, arrowheads, and number stay solid. (Dashes are honored in SVG; DXF collapses them to solid, matching how Illustrator and most DXF readers treat them.)
• Heads: the arrowheads themselves: pick the style (filled triangle, open arrow, or architectural tick), turn a head on or off per end, and set its length x width in millimeters. What you set is what exports.

Color, weight, dash, and heads all ride along with undo and are saved with your file.

Faithful export

Dimensions export as real, baked geometry - extension lines, the dimension line, the value text, and the arrowheads, all together under an Annotations group (an SVG <g> / a DXF layer). Arrowheads are baked as actual filled shapes rather than SVG markers, so they survive the round-trip into Illustrator and DXF/CAD unchanged. Because they live on their own layer, whatever reads the file next can simply ignore them.

Note

The value text size is still drawn at a fixed size and isn't adjustable yet. The arrowheads, however, are adjustable - see the Heads row above.

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