UnitySCAD

Import parametric OpenSCAD (.scad) files as Unity meshes, with live parameter editing and a Shader-Graph-style node editor.

Features

• ScriptedImporter for .scad files — drop into Assets/, get a ready-to-use prefab
• Customizer-style parameter parsing — // [min:max] ranges, // [option, option] dropdowns, hex colors, RGB vectors, booleans, descriptions, groups
• Live Preview window — embedded 3D viewport with orbit controls, debounced background recompile, process cancellation on every edit
• Node graph editor (.scadgraph) — visual authoring with ~25 typed nodes (primitives, transforms, boolean ops, extrusions, math, vectors); reverse-imports existing .scad files into an editable graph
• Per-color submeshes — separates geometry by color() calls into tinted submesh materials
• Compile cache — SHA-256-keyed disk cache, re-opening a prior parameter state is instant
• OpenSCAD auto-installer — downloads the 2025.06.22 snapshot (with the fast Manifold CSG backend) into a per-user cache; no manual PATH setup
• URP / HDRP / Built-in RP — materials resolve to the active render pipeline's default Lit shader

Requirements

• Unity 6000.0 or newer
• OpenSCAD binary (the plugin can download it for you)

Install

Via Package Manager (Git URL)

Packages/manifest.json:

{
  "dependencies": {
    "com.timskap.unityscad": "https://github.com/timskap/UnitySCAD.git"
  }
}

Pinning a version

"com.timskap.unityscad": "https://github.com/timskap/UnitySCAD.git#v0.1.0"

First-time setup

1. Open Unity → Settings → Preferences → SCAD Plugin.
2. Click Download and Install OpenSCAD 2025.06.22. Waits ~1 minute; installs into a per-user cache shared across all your Unity projects.

Usage

Imported assets

Drop a .scad file into Assets/. Unity imports it as a GameObject prefab with MeshFilter + MeshRenderer. The Inspector exposes every top-level variable in the file as an editable parameter. Click Apply to recompile.

By default Skip Compile is on so heavy models don't freeze Unity on first import — uncheck it when you want the real mesh.

Live Preview window

Window → SCAD Live Preview. Two modes:

• File — drop a .scad asset, edit parameters, see the mesh update in the embedded viewport. Commit to Asset bakes the current state into the importer meta.
• Inline Text — paste SCAD code directly, iterate, then Save as .scad Asset… writes it to the project.

Live Update debounces edits, cancels in-flight compiles on every keystroke, and overrides $fn for fast preview (configurable). Parameters change → mesh updates in a few hundred ms on a reasonable model.

Per-color output

SCAD files like this:

C_wall = [0.55, 0.38, 0.24];
C_roof = [0.28, 0.17, 0.12];
color(C_wall) cube([10, 10, 5]);
color(C_roof) translate([0, 0, 5]) cube([10, 10, 1]);

produce a mesh with two submeshes and two materials, each tinted appropriately. The plugin achieves this by running OpenSCAD once per distinct color() value, with an injected color override module filtering geometry per pass — all passes run in parallel.

Limitation: works when color() wraps standalone top-level parts. color() applied inside a difference() positive is handled correctly. RGB-vector and hex-string colors are supported; nested color() calls are not.

Parameter syntax

// Dimension group header
/* [Dimensions] */

// Width of the box
width = 20; // [5:100]

// Height with step
height = 10; // [5:0.5:50]

// Integer dropdown
quality = 30; // [10, 20, 30, 60]

// String dropdown
label = "Small"; // ["Small", "Medium", "Large"]

// Boolean
hollow = false;

// Hex color (rendered as color picker)
accent = "#C3F9BC";

// RGB-vector color (rendered as color picker)
wall = [0.55, 0.38, 0.24];

Only the top-level variables before the first module / function are treated as parameters (matches OpenSCAD Customizer semantics). Expressions like computed = a + b; are filtered out.

Node graph (.scadgraph)

Visual, Shader-Graph-style authoring for OpenSCAD geometry. Create with Assets → Create → SCAD → Graph; double-click to open in the editor window.

• Search menu (Space or right-click) is auto-populated by reflecting [ScadNode] attributes; ~25 typed nodes covering primitives (cube/sphere/cylinder/square/circle/polygon/polyhedron/text), transforms (translate/rotate/scale/mirror/color/offset/resize), boolean ops (union/difference/intersection/hull/minkowski), extrusion (linear_extrude/rotate_extrude/projection), math, and vector ops.
• Ports are typed: Number / Vector2 / Vector3 / Boolean / String / Color / Solid / Shape / Any, with Number → Vector broadcast for SCAD-style shortcuts. Compatible ports auto-connect.
• Exposed graph parameters emit as SCAD top-level variables, so they're live-editable both in the graph and downstream.

SCAD source import

The Import dropdown in the toolbar pastes SCAD source or opens a .scad file and produces a fully expanded graph. Right-clicking a .scad asset in the Project window gives the same entry point via SCAD → Convert .scad to Graph.

How it works:

1. A preprocessor extracts every module/function definition into the graph's preamble (preserved verbatim, so OpenSCAD always sees them) and also re-parses each body into AST.
2. The main parser handles the remaining top-level code — assignments, module calls, SCAD range literals [start:step:end], arithmetic expressions.
3. The graph builder inlines user-defined module calls with full argument/local-variable substitution, unrolls for-loops over constant ranges, and wires identifier references back to ParameterNodes so live edits stay wired through.
4. Anything outside the supported subset (if/else, non-constant ranges, unknown modules without parsed AST) falls back to CustomStatementNode with the SCAD text preserved — the graph always compiles.

See Documentation~/NodeGraph.md for the full architectural reference.

Performance

• Snapshot OpenSCAD + Manifold backend: auto-installed; 10–50× faster CSG than 2021.01 stable.
• Parallel multi-color compile: N colors run in min(cores, N) concurrent processes.
• Disk cache: 512 MB ring. Reopening a prior parameter combo is instant.
• Preview $fn override: live preview uses low $fn (default 12) for fast iteration; commit/import uses the file's own value.

License

MIT. See LICENSE.

OpenSCAD itself is GPL-2.0 and is not redistributed by this plugin — the auto-installer downloads it on your machine from files.openscad.org on demand.