Inkscape extension: isometric projection converter

This version of the extension is for Inkscape 1.2 or newer. For older versions of Inkscape, please use v2.1 (for Inkscape 1.0.* and 1.1.*), or v1.2 (for Inkscape versions before 1.0).

This Inkscape extension transforms objects drawn on a two-dimensional plane to an isometric or dimetric projection.

Inkscape provides an axonometric grid that by default is configured for the isometric projection (i.e., the three axes are set at 120° angles). Drawing with this grid works quite well for simple shapes, but sometimes it is easier to draw the details of an object using a two-dimensional grid, and then scale, shear, and rotate the object to set it on an isometric plane.

This extension conveniently automates these transformations.

In addition to the isometric projection (a dimetric projection where both angles are 30°), the extension supports arbitrary angles as well (here the angles are set to 15°).

This example shows a trimetric projection with two different angles for the left and right hand sides.

Installation

Copy isometric_projection.inx, dimetric_projection.inx, and axonometric_projection.py to your Inkscape extensions directory, listed at Edit » Preferences » System: User extensions. After a restart of Inkscape, the new extension will be available.

Usage

The extension can now be found in the Extensions menu under Axonometric Projection. To convert a flat two-dimensional object to one of the three visible isometric planes (i.e., top, left-hand side, and right-hand side), select the object, and perform select the desired conversion via the Isometric Projection… entry from that submenu.

To perform the opposite action (i.e., convert from one of the isometric sides to a flat two-dimensional object) select the appropiate isometric side, and enable the Reverse transformation option.

For dimetric projections using an angle other than 30°, use Axonometric Projection » Dimetric Projection…, and set the angle to an appropriate value.

For trimetric projections using different angles for the left and right hand sides, use Axonometric Projection » Trimetric Projection…, and set both angles to appropriate values.

Further reading

More information about the transformations and maths used by this extension can be found in this write-up.