Perspective Drawing with Lazy Nezumi Pro

This ruler was added in version 17.01.06. Some sub-features were added in later updates.

If you want to draw convincing 3d environments, vehicles, and even people, mastering perspective is a must. Traditionally, setting up for a perspective drawing can be tedious and time consuming, with vanishing points going way off the page, and messy construction lines everywhere. Lazy Nezumi Pro's perspective ruler will hopefully make this process faster and easier!

This particular ruler uses a type of projection called Linear Perspective (Isometric and Fisheye projections are also available as different rulers). It generates a set of guide lines that connect your current pen position to fixed vanishing points. Your lines then snap to these guides when you draw, helping you quickly construct perspective-correct objects in your scene. You have complete control over the camera setup, and can easily rotate the vanishing lines in 3D to draw objects in any orientation.

If you are working with an existing image with an unknown perspective setup, and would like to add perspective-correct elements to it, you may want to use the Vanishing Lines ruler instead. That ruler doesn't require you to know or setup any camera parameters. Instead, you can set the vanishing points directly, or have them setup automatically by lining up control lines with parallel lines from your scene. And if you're using a recent enough version, you can then easily have the Linear Perspective parameters automatically set up to match the Vanishing Lines ruler's perspective. The following video will show you an overview of both of these rulers, and the perspective matching feature.

The Linear Perspective Ruler

1. Parameter Setup

If you open the Ruler - Perspective preset's Rulers section (by clicking on the little arrow icon), you'll see several configurable parameters. This section will explain what these parameters do, and how to choose appropriate values for your perspective drawings.

1.1 Canvas Zoom

This parameter was named Image Zoom in older versions.

If you are using LNP with a version of Photoshop older than CS3, or with any other art application, you must set this parameter to match the value of your canvas zoom after you zoom in or out. You then need to realign the ruler or the perspective lines will no longer align with your scene. The easiest way to do this is to draw a mark under the view center point in a separate layer, so that you can quickly realign it with the view center when needed.

When working on an image over multiple sessions, you will have to realign the ruler when you open your document again. Starting with version 21.02.15, the ruler center position within your Photoshop canvas is now stored in your LNP preset along with the other ruler parameters when you save your preset, or save it as a new preset.

With Photoshop CS3 and up, your document's pan and zoom will be tracked automatically (this was added in LNP update 18.03.08). In this case, you do not need to change the Canvas Zoom parameter yourself (it will have no effect).

For apps where automatic tracking is not possible, you can at least enable the Settings/Spacebar Pan Offsets Ruler Centers menu to keep your center aligned while you pan your canvas (in Photoshop, be sure to uncheck Enable Flick Panning in the general preferences tab).

In any case, you should avoid rotating your canvas while using the perspective rulers. Since canvas orientation isn't sent to the plugin, this will cause the rulers to not be aligned with your scene anymore.

1.2 View Radius

This is the first parameter you should adjust when setting up for a new perspective scene. It defines the radius (in screen-space pixels) of the circle which is the intersection of the cone of vision with the image plane. You should set this parameter so that the view circle covers most of your canvas at 100% zoom.

The center of this circle is the intersection of the direction of view (or line of sight) with the image plane. It can be moved by dragging the little overlay control point, or by using a keyboard shortcut.

1.3 Field of View

This represents the field of view that is visible within your viewing circle. A small value for this parameter will produce a telescopic view, where the perspective effect is minimized (vanishing lines will seem parallel). A larger value is equivalent to a wide angle camera lense, and will project more of the world to your view circle. Note that objects drawn further out from a 60° viewing circle can start to appear unnatural and distorted, but this can be used for artistic effect.

Choosing an appropriate value for this parameter really depends on what kind of scene you are drawing. Typically, you will use a larger value for landscapes, and a smaller value for close-up shots. If you are unsure, try drawing some test scenes at both extremes to get a feel for the difference. With a large field of view, closer objects will appear much larger than they actually are. You may also want to study photographs taken with both wide angle and telephoto lenses. The smaller the focal length of a camera lens, the wider the field of view.

If you want to draw with a 180° field of view, be sure to check out the Fisheye Perspective preset!

1.4 Horizon Tilt

This feature was added in version 19.09.17.

This parameter controls the camera roll, or rotation around the Z axis.

This can be used to compose Dutch Angle shots, which can portray disorientation, psychological uneasiness, or tension in the subject being filmed or photographed.

Here is an example of such a shot from the 2010 film Inception, with our ruler lined up and rotated to match the perspective:

Did you know they actually built a rotating hallway to film this scene?

1.5 View Tilt

This parameter controls the vertical tilt of the line of sight. It corresponds to the camera's angle of rotation around the x axis, and directly controls the orientation of the vertical guide line.

When set to 0, the view direction is parallel with the ground, and all the lines going straight up and down in the scene are drawn completely vertical and parallel on the canvas.
Positive values make the line of sight point towards a point below the horizon. This is sometimes referred as "bird's eye view". In this case, the lines going up and down will not be parallel on the canvas, and will meet at a vanishing point below the horizon line (which will now be above the center of the view).
Negative values make the line of sight point towards a point above the horizon. This is sometimes referred as "worm's eye view". In this case, the lines going up and down will not be parallel on the canvas, and will meet at a vanishing point above the horizon line (which will now be below the center of the view).

1.6 Line 1 and Line 2 Angles

These parameters control the angles of the first two perspective guide lines. Contrary to the vertical guide line (controlled via View Tilt), these are primarily used for drawing lines that are parallel to the ground. They are defined by their angle on the ground plane with respect to the line of sight.

Controlling the guide lines via their 3d angles allows you to place rotated shapes anywhere in your scene, without worrying about where the actual vanishing points should be placed. For example, if you want to draw a square, the only requirement is that the difference between Line 1 and Line 2 angles is 90. But they can be rotated any way you like: -45/45, -30/60, -10/80, etc.

While the view parameters (radius, field of view, view tilt, and horizon tilt) should not be changed after you've setup your scene view, having some variation in the orientation of your objects by changing Line 1 and Line 2 angles will go a long way in making it appear more natural. To speed things up, these angles can be rotated together when the Angle Link button is checked (maintaining their separation angle constant) or separately via keyboard shortcuts, or via their control points while holding the control key.

1.7 Line 1 and Line 2 Tilt

Starting with version 19.09.17, you can control the vertical tilt angles of Line 1 and 2. This will help you draw inclined surfaces such as roofs and ramps.

If you are drawing inclined planes that share a common point, such as a pyramid, you can also use the Radial Lines ruler to draw the lines, as shown in the the following example. Use this method when you know exactly where the vanishing point is.

The following example shows how you can also use the Vanishing Lines ruler to draw a tilted roof. Simply Line up the control lines with the two edges. You can use this method if you're using an older version of LNP, or if you're working with an existing scene and don't know any of its perspective view parameters.

1.8 Line Select Mode

The Line Select Mode parameter determines which guide line is chosen when you draw:

Manual start & change: You have to manually choose which guide line to start drawing on by pressing the shift key. You can change lines while drawing by pressing the control key.
Auto start, manual change: The starting guide line will be chosen automatically based on the direction of the first few samples of your line. You can change directions while drawing by pressing the control key.
Auto start & change: Same as the previous option, but you can change lines while drawing without pressing control. This mode is great for fast 3d sketching, but not recommended if you need precise control.

1.9 Box Mode

When this is enabled, your pen position will be constrained to a 3d bounding box while you draw, helping you quickly draw perfect boxes without lifting the pen and without your lines overshooting at the corners. The dimensions of the box are determined automatically one at a time as you first draw on each axis. When set, the box sections of the vanishing lines will turn orange. The dimensions are reset when you lift the pen.

When you draw along a tilted line, this line will be treated as the diagonal of a triangle, and so box mode will automatically set the lengths for the horizontal and vertical projections. This will help you quickly close the triangle.

1.10 Match Current Vanishing Lines Ruler

Starting with version 21.10.27, the Linear Perspective ruler can try to match the perspective of the current Vanishing Lines ruler setup. This will enable you to quickly match the perspective of existing scenes, while giving you the flexibility of the Linear Perspective ruler's rotating line angles, tilting, and measure points. To do this, you can use the "Match current Vanishing Lines Ruler" button, or use the global shortcut setup via the [Settings/Edit Shortcuts] menu.

Here are the requirements for this to work:

VP1, VP2, and VP3 must all be enabled in the Vanishing Lines ruler.
VP1 and VP2 will be used to determine the horizon and the two major line angles. The vanishing lines connecting to VP1 and VP2 are assumed to be from orthogonal lines in your scene (for example, lined up with the opposite edges of a square in the scene).
If VP1 or VP2 is at infinity (with parallel control lines), a 0°/90° line setup will be assumed, and the horizon tilt angle will match the angle of the parallel control lines.
VP3 will be used to determine the View Tilt. If it is at infinity (with parallel control lines), there will be no tilt.
The current View Angle will not be changed. Instead, the View Radius will be adjusted to match the perspective. In some special cases, you may need to first decrease the View Radius or increase the View Angle to get a match.

1.11 Overlay Control Points

Many of the parameters can be controlled directly via on-screen overlay control points, which are displayed when holding the control key. Double-clicking most control points will reset them to their default values.

View Center This control point sets the point that the camera is looking at. This is the intersection of the Z axis with the image plane. Holding the shift key will slide the center point horizontally or vertically.
Horizon Tilt This lets you rotate the horizon around the view center.
View Tilt This lets you tilt the view up and down. Holding the shift key will clamp the angle to 5° increments.
Line 1 and 2 Angles These control points let you rotate Line 1 and 2 around the Y axis. Holding the shift key will clamp the angles to 5° increments.
Line 1 and 2 Tilt These control points let you rotate Line 1 and 2 around the ground plane. Holding the shift key will clamp the angles to 5° increments.
Tick Distance This lets you increase or decrease the distance between the ticks, by sliding the point along the line.
Fixed Axes Mode Clicking this control point will toggle a fixed axis base point for quick 3d measurements and comparisons.
Grids Clicking this control point (only available while in fixed axes mode) will cycle through the different grid options: XY, ZY, XZ, off.

When you slide the view center control point (while holding shift), the Fixed Axes Point stays at the same place on the canvas. This is useful in case you forgot to mark the center of your perspective scene, and are trying to get it back: hover over the corner of a pre-drawn object in your scene, activate Fixed Axes Mode, then slide the view center control point horizontally and vertically until the vanishing lines line up with the object edges.

While in Fixed Axes Mode, you can also turn on one of the grids. These can help you better visualize and plan out your perspective scenes.

Clicking on the Grids control point will cycle through the 3 grid planes: XY, ZY, XZ, off. You can adjust the size of the grid by using the yellow measure distance control point. The number of lines can be controlled via the Overlay settings window.

1.12 Keyboard Shortcuts

This preset has several useful keyboard shortcuts that can be assigned via the Settings/Edit Shortcuts menu's Ruler Shortcuts tab. Please note that these shortcuts will not override any functions that are already assigned to keys in your art application, so you'll want to use keys that don't already have a function. These will be active as long as the Settings/Ruler Param Shortcuts menu is checked. You don't have to set keys for all of these, but depending on how you work, you might find some of them very useful.

Move Center: Hold key down while moving your pen to move the center of the current ruler preset (this works with any script that uses a center position).
Perspective - Rotate Line 1: Hold key down while moving your pen from left to right to rotate Line 1 continuously.
Perspective - Rotate Line 2: Hold key down while moving your pen from left to right to rotate Line 2 continuously.
Perspective - Rotate Line 1 & Line 2 (fixed increment): Two shortcuts to rotate Line 1 and Line 2 together in fixed increments. You can set the angle of rotation for each direction.
Perspective - Rotate vertical tilt: Hold key down while moving your pen up and down to rotate the vertical tilt of the view.
Perspective - View Radius: Hold key down while moving your pen from left to right to change the view radius.
Perspective - Field Of View: Hold key down while moving your pen from left to right to change the field of view.
Perspective - Fixed Axes: Press key to toggle fixed axes mode, to create a fixed frame of reference at your pen position.
Measure point unit distance: Hold key down while moving your pen from left to right to change the measure point unit distance.
Select Line: This key changes the current starting line when Line Select Mode is set to manual.

If the center of any ruler preset goes off-screen and you can't seem to get it back, you can use the Set or Reset Scripting Center Pos shortcuts to reset it. These can be configured via the Settings/Edit Shortcuts menu's General Shortcuts tab. Please note that these shortcuts however are global, and will override any previously set function.

If you want panning with the spacebar key to offset the center automatically, enable the Spacebar Pan Offsets Ruler Centers setting.

2. Working in 3D

The tick markers on the rulers are called Measure Points. These will let you measure and compare relative distances in your 3d scene. In the Overlay Settings, you can set their quantity, size, and unit distance. You can also change the unit distance via keyboard shortcut, or the overlay control point. This will come in handy later.

You can choose to ignore them or turn them off, but if the relative proportions of objects in your scene are important, then you'll need to understand how to use them.

2.1 Understanding Tick Spacing

Since an infinite number of 3d points can project to the same 2d point, the depth of your pen position in the 3d scene can't be determined based on its 2d screen position alone. Because of this, the chosen convention is to have the depth be equal to the image plane's depth for all 2d screen positions when you are not drawing. Once you start drawing however, the depth is calculated based on the starting position and your direction of travel. You will then see the ticks get closer together as you near the horizon, or further apart if you draw away from the horizon.

A side effect of this is that the same number of ticks will not necessarily represent the same 3d distance if measured from different 2d screen positions. This would only be true if the 2d positions were at the same depth in the scene, like the two ends of a vertical line (assuming the view has no vertical tilt).

The following image illustrates this. Note how the sides of the cube measure 3 ticks if measured from a front corner position, but only 2.5 ticks if measured from a back corner position.

In summary:Only compare tick distances from a shared corner position.

2.2 Constructing a Box

Because of this, if you are drawing a 3d object while using measure points to set its dimensions, you will want to count ticks from the same 2d screen position. For example, if you wanted to draw a 3x4x5 box, you would choose a corner, then draw a 3 tick line in one direction, then draw a 4 tick line and a 5 tick line in the other directions, always starting from the same corner. Once your 3 main corner lines are drawn, you can then ignore the measure points when drawing the remaining lines (since you'll be starting from different 2d positions, the tick distances won't match). Instead, you should simply draw until an opposing guide lines up with the end of an established corner line.

2.3 Extending Sections

If you do want to draw while measuring from a different corner, you'll need to adjust the measure point unit distance. For example, if you wanted to double one of the dimensions of the box, you can place your pen over the desired center corner, and use the shortcut to change the measure point unit distance until a tick marker lines up with with the starting corner. You can then count the number of ticks between these corners, and draw a line on the other side using the same number of ticks.

While it's important to know the previous method, there's another method which is usually faster. If you enable Fixed Axes Mode (via the overlay control point, or keyboard shortcut) while your pen is over a corner of your object, you will get a fixed frame of reference at that position, and a new set of guide lines (without measure points) will start following your pen. You can now find the right distances by lining up the guides with the fixed measure points.

2.4 Subdividing Sections

While in Fixed Axes Mode, you can also quickly divide a section into equal parts. Simply change the measure point unit distance until the section is cut into the desired amount of parts, and line up the new guides to draw them. This method can be used to quickly find the center of a section, without having to draw diagonals.

2.5 Perspective Symmetry

When working in perspective, foreshortening can make it difficult to estimate the proportions of symmetric objects, especially when they aren't simple boxes. This is another thing Measure Points and Fixed Axes Mode can help you with.

For example, if you want to make sure you are drawing the other side of a symmetric curve correctly, you can use the measure points and the perspective ruler guide lines to project a number of points from the curve to the other side of the symmetry axis.

First, you enable Fixed Axes Mode at a position where one of the axis aligns with a side of your bounding rectangle (in the following example, the red horizontal axis lines up with the bottom), and another axis is at the center of the rectangle (in the example, the blue vertical axis will be the axis of symmetry). You then change the measure distance so that you have a couple tick markers on each side of the symmetry axis (three is usually sufficient, but you may need more if you have a complex curve). At each of these tick markers, you line up the vertical ruler and find the corresponding point on the curve. From that point, you draw a line until the vertical ruler lines up with the corresponding tick marker on the other side. You can then use these projected points as guides when drawing the other half of the curve.

2.6 Perspective Circles

Drawing circles in perspective can be really tricky, even for experienced artists. It's important to try to get this right however, or the viewer will immediately know that something is wrong with the drawing.

Viewed in perspective, a circle appears as an ellipse. This is great, as an ellipse is not hard to draw, but you still need to figure out how to correctly set the center, degree, and rotation, for it to look right.

If you're using a recent version of LNP, you can use the Perspective Ellipse ruler and save a lot of time! Update 19.10.22 will even help you draw perspective circles based on the current Linear Perspective ruler's settings.

If you're using an older version that doesn't have that ruler, you can use the regular Ellipse Ruler instead. As you get more practice at drawing in perspective, you will develop a feel for the correct shape and orientation of the ellipse required. Remember that it doesn't have to be perfect, it just has to look right. Here are some tips that will hopefully help:

The center of the ellipse will almost never match with the center of the circle, but it's a good starting point.
Ignore the major axis of the ellipse. It almost never intersects anything useful.
The minor axis of the ellipse should be loosely aligned with a line coming out of the circle center, which is perpendicular with its plane (like a wheel axle). Note that the further out you are drawing from the view center, the less they will align.
The ellipse should touch the perspective center point of each side of the circle's bounding square.
The ellipse should also touch the four corners of a concentric square that is 7/10 the size of the bounding square. You can easily construct this square by changing the measure point unit distance so that you have 10 tick marks on each side of the center, and then count 7 ticks from the center for each side (in the following example, we used a little under 3/4 for clarity). This step gives you four additional points to line up with, and can help fine tune the placement.

2.7 Line Attenuation

If you are drawing large structures, attenuating the line size as you get closer to the vanishing point can really contribute to the impression of depth.

If you have your pen pressure mapped to the brush size, you can do this yourself by slowly easing off the pressure as you draw the line. But this can be hard to control, and if you're drawing more than one line, it'll be hard to get a consistent look.

LNP's scripting capabilities can help with this! While you have the perspective ruler enabled, enable scripting, and select the perspective fade mode from the Pressure category. Your pressure will now be automatically attenuated as you get closer to a vanishing point. This lets you draw with a natural, constant pressure feel, and will give you consistent attenuation for all your lines. The attenuation parameter allows you to adjust the rate at which the pressure gets attenuated.

Note that for best effect, you should also decrease your brush size when drawing lines that start further away in depth.