Note that an up to date version of this manual is included in the distribution as a .pdf file







  • Initial release



  • Multiple reference planes

  • Flip normal button in display

  • UI tweaks

  • Added missing documentation on display options



  • Double key release on Ubuntu 18.04 work around



  • Port to 2.8x



  • Tested against 2.83LTS

  • Bug fix: crash when operating on empty selection

  • Fixed warnings due to code naming conventions

  • Ported to 2.93LTS


First time installation

Installing Ortho for the first time is simple:

  • Unpack the .zip file 

you probably already have done that as it contains this document (Orthousermanual.pdf) and the add-on itself (an archive with Python files,, where the yyyymmdd portion of the name is a timestamp that may vary)

  • Select Edit → Preferences ... → Add-ons from the menu

  • Click ‘Install  …’ (at the top of the screen) and select the file

  • Click ‘Install Add-on’ (at the lower right)

  • Check the enable check box to the left of the add-on you just installed

The add-on operators will now be available in Edit mode from the Ortho tab in the 3d-View Toolbar (press Ctrl-T if the toolbar is not visible).

Installing a newer version of Ortho

If you want to replace a previous version of Ortho you have to remove the old version first. To do this, go to Edit → Preferences … → Add-ons and either search for Ortho or go to the ‘Mesh’ category where it will be located. Click on the add-on and then on the ‘Remove’ button. After removing the old version follow the instructions above to install the new version.


A sample workflow is illustrated in this walkthrough video as well in detail, here we describe the man steps, pointing you to the relevant parts in the manual.

When you want to position a mesh part accurately you generally follow the a few steps:

  • Join the mesh part to the larger mesh you are working on

  • Position the reference plane at a chosen position on the main mesh object with PlaneFit tool

  • Select some geometry on the mesh part and align and/or snap it to the reference plane with the Align tool

  • Optionally move, rotate or scale the mesh part relative to the reference plane

When cleaning up a part of your mesh that is slightly distorted, you might want to process as follows:

  • Select all the faces that should be in a single plane

  • Position the reference plane with PlaneFit tool

  • scale the mesh part relative to the reference plane, entering 0 + return to scale it exactly to zero in the direction of the reference plane normal


The tools that Ortho offers are available in the 3D view in edit mode. They can be accessed in two ways. The first is as a list of buttons in the Ortho tab of the Tools area (press ctrl-T if the tools are not visible).

The second way is as a pie menu that will pop up if you press Cmd-O (that is the ‘Windows’ key or ‘Apple’ key on most keyboards plus the letter O. Press both at the same time).

You can disable this shortcut in the add-on preferences and configure a different shortcut in the File → User preferences → Input section if you like. The add-on preferences section also give details on which operator name to use to achieve this.

Ortho Plane Map

It is possible to keep a list of separate reference planes and manage them in the Ortho Plane Map panel:

Everytime you create a reference plane  with the PlaneFit operator you replace the active plane. You can create additional planes with the + key and select any of them by clicking on an item in the list. You can also remove and reorder the the list and assign meaningful names by double clicking an item.

If you remove all items a new one will  be created automatically once you execute the PlaneFit operator again.

Tool & options reference


The PlaneFit tool will create a plane that best fits any selected vertices. It will show the normal and its x and y axes in cyan, green an red respectively, and the plane in semi transparent white. These colors can changed in the add-on preferences.

You may change the size and toggle the visibility of the plane with the options in the Ortho panel in the 3d-view options (press ctrl-N if the option panel is not selected)

The center of the reference plane, the centroid, is displayed as a small white dot.


Although the reference plane is infinite it is displayed with a finite size. The directions of its x and y axes are aligned with the major directions of the vertices it was fitted to. By checking align you have the option to select which coordinate system to use to which the x and y axes will be aligned as well as possible.

Principal will align the x-axis with the most common direction of the selected edges while local and global will try to align with the x and y axes of the local and global coordinate systems respectively.

Flip normal

Reverse the direction that the normal is pointing.


The Align tool will align selected vertices, and possibly connected geometry, to the reference plane. This is accomplished by fitting a plane through any selected vertices and rotating those vertices in such a way that this plane will be parallel to the reference plane.

Optionally the vertices will be moved as well so that the median point will coincide with the reference plane or even to the centroid.


This option determines if only the selected [Selected] vertices will be moved, vertices that are connected [Connected] or those vertices for which the edges between the selected vertices form a boundary loop [Region]. That last item comes with an additional option to select either the smaller or larger boundary region.

Select Bigger

Select either the smaller or larger boundary region.


These buttons offer a quick way to rotate the aligned vertices in 90° steps around the normal of the reference plane.


If checked vertices will be moved in such a way that the median point of the selected ones will be coplanar with the reference plane.

To centroid

If Snap is checked, checking To centroid will make sure that the median point of the selected vertices will coincide with the centroid.


The move tool moves selected geometry along the normal of the reference plane or along on of the references axes.

It behaves much like the grab tool in regular edits. As long as you move the mouse you keep moving the selected geometry until you hit ESC, or one of the mouse buttons.

Pressing Ctrl limits movements to fixed increments, while pressing Shift will make movement slower and more precise and entering a number will let you choose an exact displacement.

You can even switch to Scale or Rotate mode by pressing S or R respectively.

A small reminder is shown in the lower status area:

The available keystrokes are summarized in this table:

Key or mouse button



Toggle restrict movement to X-axis 


Toggle restrict movement to Y-axis 


Restrict movement to Normal 

Shift N

Restrict movement to XY-plane


Toggle distance calculation from relative to initial cursor to relative to centroid of reference plane and nice versa


Restrict movement to fixed increments


Reduce movement (more precision)

. (dot) - (minus) or any digit followed by Enter 

Enter a numerical distance

Esc or Left mouse or Right mouse

Leave Move mode


Switch to rotation mode


Switch to scale mode


The Rotate tool rotates the selected geometry around the normal of the reference plane or one of the other reference axes. Just like the move tool it allows for precise manipulation with the Shift and Ctrl keys as well as numerical input. For all available keystrokes see Move


The Scale tool scales the selected geometry along the normal of the reference plane or one of the other reference axes, with the centroid of the reference plane as the center of the scaling operation. Just like the move tool it allows for precise manipulation with the Shift and Ctrl keys as well as numerical input. For all available keystrokes see Move


The Duplicate tool duplicates the selected geometry and then starts the Move tool. It is a convenient shortcut that acts much like Shift-D does.

Snap centroid

Snap centroid moves the centroid of the reference plane to a new location without changing the orientation of the plane. It comes in two flavors: unconstrained and constrained.

A constrained snap will move the centroid as close as possible to the center of the selected geometry while making sure that the centroid will stay inside the current reference plane. So the plane will not move, just its center.

An unconstrained snap will simply move the centroid to the new location even if it is not within the plane. The orientation of the plane however will not change.

Display options

Some of the visual characteristics of an active reference plane can be control in the Ortho panel of the display options in the 3d-view (Press Ctrl-N if those are not visible)

Show reference plane

With this option the visibility of the reference plane can be toggled.


This option controls the size of the plane

Flip normal

This lets you inversie the direction of the normal. The direction of the normal affects direction of the movement of geometry along this normal.


The Ortho add-on has several attributes that can be changed in its preferences. The color swatches allow you to change the color and transparency of the reference plane as well as the colors used for the normal and the reference axes.

Also, by default a keyboard shortcut is created for the Windows-Key + O (Or Cmd-Key + O) that will pop up the pie menu. If you would like to use a different shortcut for example because your operating system already uses this for another purpose, you can disable the default one and create one yourself. See Can I change the default shortcut?

The Bounce protect option (not enabled by default) will prevent automatically generated key release events from causing troubles on some operating systems (notably Ubuntu 18.04). If you notice that when moving an object along the reference plane switching references axes by pressing X, Y or N is impossible, enabling this option may help.

Frequently asked questions

Can I change the default shortcut?

Yes you can: you can disable the default shortcut by selecting User preferences → Add-ons → Mesh → Ortho and then unchecking ‘Create OSKEY-O Shortcut’.

There is a helpful hint below those preferences that tells how to create a keyboard shortcut of your own choice:

Goto User preferences → Input → 3d View → Mesh

Click on ‘Add new’ and select a keyboard combo that you like (it must of course not be in use already). In the image below we have chosen the impossible to enter keyboard combination Shift-Ctrl-Alt-Cmd-A.  

For the operator identifier, use wm.call_menu_pie and for the Name use mesh.ortho_pie

I am using Ubuntu 18.04 and my keys are dead, what’s up?

If you cannot change the reference axis by pressing X, Y or N or cannot change modes to scaling or rotating by pressing S and R respectively, your operating system might send automatically generated repeat key events to Blender and therefore to the Ortho add-on. You can disable this in the add-on preferences by checking the Bounce protect option.

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Published over 6 years ago
Blender Version 2.79, 2.8, 2.81, 2.82, 2.83, 2.93
License GPL
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