scad-app: SCAD rendering interface

scad-app is a small library for parallel rendering of model assets created with Matthew Farrell’s scad-clj.

At its most basic, this library writes SCAD files from Clojure. Concurrency is done with core.async, automatically using a reasonable amount of CPU threads for your hardware.

Other features, all through control of OpenSCAD:

• Rendering to STL.
• Rendering to 2D image formats. Multiple views per model.
• Management of reusable modules, including support for chirality.
• File-level settings for resolution, e.g. facet count.

Usage

First, package your model as a scad-app asset. An asset is a Clojure map with a simple schema. At minimum, an asset must have a :name and some source of specifications for your model. There are three options:

1. :model-main is a single scad-clj spec like (circle 1).
2. :model-vector is a vector of such scad-clj specs.
3. :model-fn is a nullary function that returns either of the above.

These three are all interchangeable, but you must supply at least one with each asset. Here’s an example program that defines and builds a complete asset:

(ns hello-cube
  (:require [scad-app.core :refer [build-all]]
            [scad-clj.model :refer [cube]]))

(def assets {:name "cuboid", :model-main (cube 1 2 3)})

(build-all assets)

By default, this will produce a file called output/scad/cuboid.scad, containing only the OpenSCAD code for the example asset. Along the way, you will get progress reports to *out*, e.g. your terminal.

Advanced features

2D views (:images) and limits on resolution (e.g. :minimum-facet-angle) can be added directly to assets.

Things like how the file paths are built, whether and how to render to STL etc. are all configurable by passing options to build-all.

To duplicate a chiral asset in a mirrored version, and/or inject modules into its model vector, call refine-asset first. Modules are themselves packaged as assets.

Template

scad-app is made easy through the cad Leiningen template here.

Demo

This repository comes with a demo of how concurrency is handled. This demo doesn’t build any files but it makes a nice sandbox if you wish to test an improvement to the library.

Run it like this: lein exec -p src/demo/core.clj

License

Copyright © 2019–2021 Viktor Eikman.

This software is distributed under the Eclipse Public License, (EPL) v2.0 or any later version thereof. This software may also be made available under the GNU General Public License (GPL), v3.0 or any later version thereof, as a secondary license hereby granted under the terms of the EPL.