Lazy Nezumi Pro Rulers

Along with its stabilization and scripting capabilities, Lazy Nezumi Pro offers some pretty useful rulers that will help with technical drawing. This guide will show you how to use them.

Ruler Parameters

When a ruler is active, guides will be displayed over your canvas. These are rendered on a transparent overlay window. You can control its opacity and other settings via Settings/Edit Overlay Settings. While you're there, be sure to enable Direct2D for improved performance. Note: The recent Win10 Creator Update has broken the Direct2D renderer, so you'll have to keep it disabled, or uninstall the update.

Most of the ruler modes have parameters that control how the ruler behaves. They can be controlled the following ways:

  • Via the parameter slider or numeric box in the UI;
  • via the on-screen control point graphics, while holding the control key;
  • via individual keyboard shortcuts, which can be configured via Settings/Edit Shortcuts/Ruler Shortcuts.

You'll also notice that all ruler modes have a common Accuracy parameter. When set to a value of 1, the line you draw will be fully projected onto the selected ruler. The closer this value gets to 0, the more of your original input gets mixed in, letting you add imperfections to make the lines look more natural. Set it to 0 if you don't want your line to snap to the ruler at all, but still wish to see the overlay guide. You can configure the Ruler Accuracy Off/Restore global shortcut to quickly toggle this parameter.


LNP Ellipse UI

This mode will help you draw ellipses and circles. It has the following parameters:

  • Degree - The degree of the ellipse. Set it to 90 for a circle.
  • Rotation - Rotation of the ellipse minor axis (from the horizontal).
  • Connect Ends - When accuracy is lower than 1, checking this option will ensure that none of your original input gets mixed in towards the start and end of the ellipse, effectively helping you connect the ends neatly.

The ellipse center can be moved around by dragging its center point. The size of the ellipse is determined by your pen down position. It is currently not possible to lock the ellipse to a certain size. If you look at the minor and major axis, a portion of them will be orange. This indicates the size of the last drawn ellipse. Use these guides if you need to draw multiple ellipses of the same size at different locations, or disconnected portions of the same ellipse.

The Auto Fit button (or associated global shortcut) can help you find good parameters automatically. Simply press the button, then sketch an ellipse (it doesn't have to be complete), and LNP will try to find the best parameters that fit your sketch! You can then fine-tune via the interactive control points.

You can activate the interactive control points by holding the control key. You'll notice that the center point becomes yellow. In this mode, it slides along the minor or major axis. Hold shift while using the rotation handle to clamp to 5 degree increments.

LNP Ellipse Ruler Control Points

When this ruler is active, you can use the following predefined input variables when scripting:

  • dn - Normalized distance around the circle/ellipse. This can be used to sync patterns that need to repeat exactly when going around more than once.
  • eh - The current ellipse height. This can be used to modulate pattern sizes based on the size of the ellipse you are drawing.

See the Circular Patterns script modes for examples on how to use these. The Misc - Gears preset uses the circular square wave mode to create perfect gear shapes.

LNP Ellipse Ruler + Circular Square Wave Script

Radial Lines

LNP Radial Lines UI

This mode will help you draw lines that radiate out from a center point. This is often used in illustration to give the impression of motion and dynamics.

It has one Curve parameter that will let you create curved radial lines. These are simple quadratic curves.

The center point can be moved around by dragging the control point. Holding the control key will also show the curve control point.

LNP Radial Lines Ruler Control Points

The script modes in the Radial Patterns can be used with this ruler. Here's the Radial Fade script mode in action. This script will automatically attenuate the pressure of your stroke as it approaches the center.

LNP Ellipse Radial Fade

Parallel Lines

LNP Parallel Lines UI

This mode will help you draw parallel lines. It has one angle parameter that lets you rotate the line.

You can also change the angle by using the control point while holding down the control key, or by holding space (rotate around current pen position) or shift (rotate around last pen up position).

While holding control, you can also adjust the unit distance between the measure points by sliding the yellow control point.

LNP Parallel Lines Ruler Control Points

Connected Lines

LNP Connected Lines UI

This mode is useful for constructing shapes from straight lines, where the start of each new line is connected to either the start or end of the previous line.

You can press shift to change the connection point. While holding control, you can also change the measure point unit distance by sliding the yellow control point.

LNP Connected Lines Ruler Control Points LNP Connected Lines Ruler

Use the Stop at connection point option to prevent your line from overshooting past the connection point.

LNP Connected Lines Ruler

Isometric Perspective

LNP Isometric UI

Isometric projection is a method for visually representing three-dimensional objects in two dimensions in technical and engineering drawings. It is often used in game art.

This mode will help you draw isometric art. It has 3 rulers for which you can change the angles.

The Line Snap Mode parameter determines which line your pen will snap to when drawing. You can turn it off to enable free drawing while still displaying the rulers, set it to auto detect from the start of your line, or set it to manual for better control (pressing shift will then change the focus).

Holding the control key will also display the angle control points, and the measure point unit distance control point.

LNP Isometric Ruler Control Points

Pressing the Perspective Freeze keyboard shortcut will create a fixed frame of reference at your pen position. You can use this and the measure points to accurately subdivide sections.

Fisheye Perspective

LNP Fisheye UI

Whereas linear perspective projects straight 3d lines to straight 2d lines, fisheye perspective projects them to curved 2d lines. This perspective mode has a fixed view angle of 180 degrees. Half of the world is effectively projected onto the view circle.

The view circle is controlled by its center point and View Radius parameter. Be sure to set the Image Zoom parameter to your current canvas zoom level. It is also recommended to draw a mark under the center in a separate layer, so you can realign it easily.

This mode does not let you change the line angles. You can choose between a horizontal line, a vertical line, and a line going to the view center.

Holding the control key will display the measure point unit distance control point.

Pressing the Perspective Freeze keyboard shortcut will create a fixed frame of reference at your pen position. Like with the Isometric and Linear Perspective rulers, you can use this and the measure points to accurately subdivide sections.

LNP Fisheye Perspective Measure Control Point

Linear Perspective

This mode has its own detailed tutorial here.