Implemented OpenSCAD support to models in STEP format.

.gitignore

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+node_modules/
+**/node_modules/
+dist/
+**/dist/
+*.js
+*.js.map
+*.d.ts
+*.d.ts.map
+**/*.js
+**/*.js.map
+**/*.d.ts
+**/*.d.ts.map

openscad-step-export/README.md

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+# OpenSCAD STEP Export
+
+This project implements a robust STEP file exporter for OpenSCAD, developed as part of the GSoC 3D-CAD initiative. It allows exporting OpenSCAD models directly to the industry-standard STEP format (ISO-10303-21 AP214) as faceted BREP geometry.
+
+## Features
+
+- **Standard Primitives**: Full support for `cube`, `sphere`, and `cylinder`.
+- **Transformations**: `translate`, `rotate`, `scale`, `mirror`, and `multmatrix`.
+- **CSG Operations**: Robust (faceted) implementations of `union`, `difference`, `intersection`, and `hull`.
+- **Extrusions**: Support for `linear_extrude` including `twist` and `scale`.
+- **OpenSCAD Language**: Evaluation of modules, functions, for-loops, if/else, and all standard expression types.
+- **STEP Validation**: Integrated validator ensuring high-integrity output with no dangling entity references.
+- **Standalone CLI**: Simple command-line interface for batch processing or integration into other tools.
+
+## Installation
+
+```bash
+# Clone the repository and navigate to the project folder
+cd openscad-step-export
+
+# Install dependencies
+npm install
+
+# Build the project
+npm run build
+```
+
+## Usage
+
+### Command Line Interface (CLI)
+
+Use the CLI to convert any `.scad` file to `.step`:
+
+```bash
+# Basic export
+node dist/cli.js -i my_model.scad -o my_model.step
+
+# Export with structural validation
+node dist/cli.js -i my_model.scad --validate
+
+# Customizing $fn resolution
+node dist/cli.js -i my_model.scad --fn 32
+```
+
+### Scripting API
+
+You can also use the library programmatically in your own TypeScript/Node.js projects:
+
+```typescript
+import { OpenScadStepEvaluator, exportSolidsToStep } from './dist/index.js';
+import { Parser, Lexer, CodeFile, ErrorCollector } from 'openscad-parser';
+
+// 1. Parse your SCAD code
+const code = 'cube(10);';
+const file = new CodeFile('test.scad', code);
+// ... parse to AST using openscad-parser ...
+
+// 2. Evaluate to Solid geometry
+const evaluator = new OpenScadStepEvaluator();
+const solids = evaluator.evaluate(ast);
+
+// 3. Export to STEP string
+const stepString = exportSolidsToStep(solids, {
+    author: "Your Name",
+    modelName: "My Part"
+});
+```
+
+## Development and Testing
+
+The project includes a comprehensive suite of over 30 tests covering geometry math, AST evaluation, and the STEP exporter itself.
+
+```bash
+npm test
+```
+
+## Project Structure
+
+- `src/geometry.ts`: Core 3D math and CSG mesh engine.
+- `src/step-evaluator.ts`: OpenSCAD AST interpreter (evaluation logic).
+- `src/step-exporter.ts`: ISO-10303-21 (STEP) file formatter.
+- `src/step-validator.ts`: Structural integrity checker for STEP output.
+- `src/cli.ts`: Command-line interface logic.
+- `src/tests/`: Comprehensive regression test suite.
+
+## License
+
+MIT - See the `package.json` for details.

openscad-step-export/fixtures/complex-model.scad

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+// Complex model exercising CSG, modules, functions, and loops
+x = 20;
+
+function edge(v) = v * 2;
+
+module my_part(size) {
+    translate([size, 0, 0]) cube(size);
+}
+
+// Loop generating translated spheres
+for (i = [0:5:20]) {
+    translate([i, 0, i]) sphere(r=2, $fn=8);
+}
+
+// Boolean difference
+difference() {
+    cube(size=10, center=true);
+    sphere(r=7, $fn=12);
+}
+
+// Boolean intersection
+intersection() {
+    cube(size=10, center=true);
+    sphere(r=7, $fn=12);
+}
+
+// Hull of two cubes
+hull() {
+    cube(2);
+    translate([8, 0, 0]) cube(2);
+}
+
+// Union + cone
+union() {
+    cylinder(h=6, r1=2, r2=1, center=true, $fn=8);
+    translate([0, 0, -5]) cube(3, center=true);
+}
+
+// Custom module call
+my_part(5);

openscad-step-export/fixtures/simple-cube.scad

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+// Simple cube – smoke test
+cube(10);