Blender

Behind the scenes, Coldtype uses the Skia library to rasterize two-dimensional vectors. But what if we want to rasterize three-dimensional graphics? One option is to use Blender.

Because Blender has an incredible Python API, it’s not too difficult to use it programmatically — i.e. to write a normal Coldtype script, mark a few things (with metadata specific to Blender), and then let Blender & Coldtype take care of the translation to three dimensions. Here’s an example:

from coldtype.blender import *

fnt = Font.Find("SwearCilatiVariable")

@b3d_animation(timeline=60)
def varfont(f):
    return (Glyphwise("Vari", lambda g:
        Style(fnt, 325,
            opsz=f.adj(-g.i*5).e("seio", 1, rng=(0.98, 0)),
            wght=f.adj(-g.i*15).e("seio", 1, rng=(0.98, 0))
            ))
        .align(f.a.r)
        .mapv(lambda i, p: p
            .ch(b3d(lambda bp: bp
                .extrude(f.adj(-i*5)
                    .e("ceio", 1, rng=(0.015, 3)))))))

Running Code in Blender

First off, your virtual environment needs to be built with the same version of Python as the Blender version you’re targeting.

Behind the scenes, Coldtype uses a tool called b3denv to communicate with Blender, and b3denv — installed as a dependency of Coldtype — makes it easy to create a virtual environment using the Python bundled with Blender.

b3denv python -m venv benv

Now you’ll have a blender-specific virtual environment named benv, which you can activate the usual way, source benv/scripts/activate on Mac.

To get a Blender window to show up, all you need to do is use the @b3d_animation decorator in place of the standard @animation decorator, and add -bw 1 to the command-line invocation. Or, if you want a set of sensible CLI defaults, try -p b3d instead, which stands for --profile=b3d and sets -bw 1 as part of some other settings in the b3d profile.

So, to use an example from the Coldtype repo, you could save the code from above and run:

coldtype examples/blender/varfont.py -p b3d

This should launch both a standard Coldtype window (with a 2D Skia renderer) and a Blender GUI window, which should automatically render the same thing as the 2D window, except in 3D. Put another way: you do not need to open Blender yourself, since Coldtype launches it as a background process (necessary to connect the live-code-reloading part of Coldtype to Blender). To quit both Coldtype and Blender, just hit ctrl-c in the terminal.

What’s different in Blender is that the contents of the scene aren’t re-created from scratch every time you render; instead, you annotate specific elements in your returned result, then those annotated results are displayed in Blender, as persistent objects. This means you can use Blender in a hybrid fashion, creating objects using the GUI, saving the file, and then re-saving your Coldtype source file for automatic updates in Blender itself.

If you’d like to skip seeing the 2D Coldtype window, you can use --b3dlo instead.