openscad-bosl2-mastery

name	openscad-bosl2-mastery
description	Use when Gemini CLI is implementing geometry using the BOSL2 library.

OpenSCAD BOSL2 Mastery

Note: This content was generated with the assistance of AI.

Overview

A guide to mastering the Belfry OpenSCAD Library v2 (BOSL2), focusing on intent-based positioning and advanced primitives.

Key Concepts

Attachments & Anchors

• Attachments: Position objects relative to each other using the attach module.
• Anchors: Named points on a shape (e.g., TOP, BOTTOM, LEFT, RIGHT, FRONT, BACK).
• Syntax: attach(TOP) cuboid([10, 10, 5]); to place a cuboid on the top face of the parent.

Shorthands (Commonly Used)

• up(z): Equivalent to translate([0,0,z]).
• left(x): Equivalent to translate([-x,0,0]).
• right(x): Equivalent to translate([x,0,0]).
• fwd(y): Equivalent to translate([0,-y,0]).
• back(y): Equivalent to translate([0,y,0]).
• xrot(angle), yrot(angle), zrot(angle): Axis-specific rotations.

Extended Primitives

• cuboid([w, d, h], rounding=r, edges=[TOP, FRONT]): Cube with built-in rounding.
• cyl(h=h, d=d, rounding1=r1, rounding2=r2): Cylinder with rounded ends.

Best Practices

1. Avoid translate: Use up, down, left, right for clarity.
2. Prioritize attach: Use it for all relative positioning to ensure the model remains parametric.
3. Use std.scad: Always include <BOSL2/std.scad> to get all core features.

Advanced Techniques

• Masking: Use the mask2d and mask3d modules for complex edge subtractions.
• VNFs: Use for high-performance custom polyhedra.