This plugin provides essential tools to accelerate your workflow for 2D and UI game object positioning within Unity 2D, Unity GUI Canvas and NGUI.

The Ruler 2D toolset is similar to the 2D layout tools provided by industry standard software like Adobe Photoshop or Adobe Illustrator. It provides rulers in the Scene View, the ability to drag guides from the rulers, a comprehensive alignment & distribution toolbox, a measuring tool, and a Grid creation panel with the ability to snap objects to the grid.

You can work with 3D scenes as well as long as the Scene View is set to 2D orthographic view mode.

To launch the plugin select Window ▶ Ruler 2D ▶ Open from the Unity menu bar. Alternatively you can use the CMD + \ shortcut on Mac or CTRL + \ on Windows.

Note that the plugin ships with its full source code (found in the R2D folder) and can be modified and enhanced with new functionality to suit any special scenarios.

Context

The Context dropdrown changes the coordinate system for Ruler 2D allowing you to work with either the standard Unity 2D view, a Unity GUI Canvas or NGUI. If you have a Unity GUI Canvas in the scene for example, the coordinate system will shift to respect the way objects are measured within the canvas, including scaling and origin.

Make sure you always set your Context correctly before working with the Unity GUI Canvas or NGUI since the default setting is the standard Unity 2D view. This dropdown will be populated with new context options only when Ruler 2D detects a Canvas or NGUI root on the scene.

Show Selected Coordinates

Enabling this option displays selected object coordinates in the Scene View.

Prefer Colliders

When Prefer Colliders is checked, Ruler 2D will use selected objects attached colliders instead of render bounds for all Toolbox operations. If an object does not have a collider it will fallback to the object render bounds.

Show Guides

This checkbox hides or shows the guides in the Scene View. You can also use the shortcut keys CMD + ; on Mac or CTRL + ; on Windows to toggle this setting. You can also lock the guides into position using the Option + CMD + ; keys on MAC or Alt + CMD + ; keys on Windows.

Snap Guides To Integer

You create guides by dragging from the rulers on the Scene View and then release to set the guide in place. If this setting is enabled, the guide will snap to the nearest integer value on the ruler.

Snap Edges To Guides

The Toolbox has a tool that allows you to snap objects to guides that you have set in the Scene View. Enabling this setting, will snap the objects to the guides using the object edges as opposed to the center of the objects.

The Toolbox

Align

Select two or more objects in the Hierarchy in order to enable the align tools. Note that enabling ‘Prefer Colliders’ in the Settings Panel allows you to work with colliders instead of render bounds (visual appearance of the object).The tools above perform the following operations in order:
• Align top edges to the highest top edge
• Align vertical centers to the average vertical center
• Align bottom edges to the lowest bottom edge
• Align left edges to the left most edge
• Align horizontal centers to the average horizontal center
• Align right edges to the right most edge

Distribute

Select three or more objects in the Hierarchy in order to enable the distribute tools. The distribute operation maintains boundary object positions based on the selected edge type (or center) and then averages out the spacing of the object edges (or centers) between the two boundary objects. The tools above perform the following operations in order:
• Distribute objects based on their top edges
• Distribute objects based on their vertical centers
• Distribute objects based on the bottom edges
• Distribute objects based on their left edges
• Distribute objects based on their horizontal centers • Distribute objects based on their right edges

Spacing

The spacing operations allow you to insert a speci ed amount of hori- zontal or vertical space between selected objects. The lowest X coordinate and lowest Y coordinates are maintained while the rest of the objects are adjusted. Note that the objects must be visually placed in the correct se- quence for proper results and the order of selection is ignored.

Snap To Guides

These operations are enabled when you have objects selected and their
are horizontal or vertical guides visible in the Scene View. They allow you to snap the selected objects to the guides in the direction indicated on the tool. Note that the ‘Snap Edges To Guides’ option in the Settings Panel al- lows you to specify whether you want to use object edges vs object centers. The tools above perform the following operations in order:
• Snap to the nearest guide towards left
• Snap to the nearest guide towards right • Snap to the nearest guide upward
• Snap to the nearest guide downward

Measure

The Measure tool allows you to draw a measuring line in the Scene View and read its length and angle. You can also select two objects and automatically draw a measuring line between the two.
• To draw a measuring line, press the ruler button and the Scene View will be ready for you to draw the line. Note that you cannot select objects in the Scene when the measure tool is ready. Pressing the button again or com- pleting the measuring line disables the measuring tool.
• To draw a measuring line between two objects, select the objects and press the distance button.
• To clear the existing measuring line, press the eraser button.

Clear Guides

This button will permanently delete all the guides in the Scene View. Note that if you want to temporarily hide the guides instead you can toggle the ‘Show Guides’ checkbox in the Settings Panel. You can also use the shortcut keys CMD + Shift + H on Mac or CTRL + Shift + H on Windows to show or hide guides.

The Grid Panel