Verify OpenSCAD libraries (BOSL2, Round-Anything) are installed, troubleshoot common issues, understand best practices for spiral generation, and evaluate designs against professional CAD quality...
This skill verifies that OpenSCAD libraries (BOSL2, Round-Anything, etc.) are properly installed and provides guidance on common usage issues.
User's OpenSCAD libraries are located at:
/Users/aaronmontgomery/Documents/OpenSCAD/libraries/
Current installed libraries:
ls -la ~/Documents/OpenSCAD/libraries/
Expected output should show:
BOSL2/ directoryRound-Anything/ directoryGenerate a test file that imports both libraries and renders basic shapes:
include <BOSL2/std.scad>
include <Round-Anything/polyround.scad>
// Test BOSL2
echo("BOSL2 Version: ", BOSL_VERSION);
cuboid([20, 20, 20], rounding=2);
// Test Round-Anything
translate([30, 0, 0])
polyRoundExtrude([[0,0,2], [10,0,2], [10,10,2], [0,10,2]], 5);
BOSL2 replaces standard OpenSCAD primitives with "attachable" versions:
cube() → attachable cube with anchor/spin/orient parameterscylinder() → attachable cylindersphere() → attachable sphereCommon Error:
ERROR: Assertion '!approx(spin_dir, [0, 0, 0])' failed:
"spin direction is parallel to anchor"
Cause: Using standard OpenSCAD syntax with BOSL2-overridden primitives.
Solutions:
Option 1 - Use BOSL2 Primitives:
include <BOSL2/std.scad>
// Instead of: cube([10, 10, 10]);
cuboid([10, 10, 10]);
// Instead of: cylinder(h=20, d=10);
cyl(h=20, d=10);
Option 2 - Don't Include BOSL2 for Simple Models: If you only need basic primitives, avoid including BOSL2:
// Use standard OpenSCAD only
cube([10, 10, 10]);
cylinder(h=20, d=10);
Option 3 - Use Standard Namespace:
include <BOSL2/std.scad>
// Explicitly use standard version
translate([0,0,0]) cube([10,10,10]); // Standard cube
Use BOSL2 when you need:
Don't use BOSL2 if:
When creating spirals with discrete segments:
Critical Rules:
Segment width must exceed angular spacing:
segment_width ≥ (360 / steps) * radius * π/180 * overlap_factor
Use hull() for continuity:
for (i = [0 : steps-1]) {
hull() {
rotate([0, 0, i * angle_step]) segment();
rotate([0, 0, (i+1) * angle_step]) segment();
}
}
Avoid thin radial slices:
Use difference() for openings:
difference() {
union() {
// Build complete spiral
spiral_ramp();
}
// Cut entry slot
entry_slot_cut();
}
Don't try to skip segments during generation - creates edge cases and gaps.
Symptom: "Can't open library" error
Solution: Verify libraries are in ~/Documents/OpenSCAD/libraries/
Symptom: Functions don't work as expected
Solution: Check BOSL2 version: echo(BOSL_VERSION);
Symptom: "spin direction is parallel to anchor"
Solution: Use BOSL2 primitives (cuboid()) or avoid including BOSL2
Symptom: "Object may not be a valid 2-manifold" Cause: Overlapping segments without proper union Solution: Usually printable if Preview looks correct, but verify with Render (F6)
Symptom: Spiral looks like a picket fence Solution: Increase segment_width to ≥1.5x angular spacing
The skill includes a Python script to generate test files:
# scripts/create_library_test.py
import os
test_code = '''include <BOSL2/std.scad>
include <Round-Anything/polyround.scad>
echo("BOSL2 Version: ", BOSL_VERSION);
cuboid([20, 20, 20], rounding=2);
translate([30, 0, 0])
polyRoundExtrude([[0,0,2], [10,0,2], [10,10,2], [0,10,2]], 5);
'''
output_path = os.path.expanduser('~/Documents/OpenSCAD/library-test.scad')
with open(output_path, 'w') as f:
f.write(test_code)
print(f"Created test file: {output_path}")
OpenSCAD error?
├─ "Can't open library"
│ └─ Check ~/Documents/OpenSCAD/libraries/ exists
│ └─ Verify BOSL2/ and Round-Anything/ folders present
│
├─ "spin direction is parallel to anchor"
│ └─ Using cube() with BOSL2 included
│ └─ Replace with cuboid() or remove BOSL2 include
│
├─ Gaps in spiral/surface
│ └─ Check segment_width calculation
│ └─ Increase to ≥1.5x angular spacing
│
└─ Non-manifold geometry
└─ Check Preview looks correct
├─ If yes: Usually printable, proceed
└─ If no: Check for floating pieces, missing unions
It is a common pitfall to believe a model is "done" simply because it renders without CGAL errors and is printable. This is the standard for a functional prototype, not a professional product.
When evaluating your design, apply the "Human Standard" test: Would a professional CAD designer at a major toy or consumer product company ship this design?
| Feature | Functional Prototype Standard (e.g., v1.4) | Professional Product Standard (e.g., proposed v1.6) |
|---|---|---|
| Edges | Sharp, mathematical corners. | All touchable edges have fillets or chamfers for comfort and safety. |
| Terminations | Cylinders and walls end abruptly with flat faces. | Terminations are capped, domed, or tapered (e.g., a rounded funnel lip). |
| Transitions | Components intersect at sharp 90° angles. | Major intersections have generous fillets to distribute stress and look deliberate (e.g., pillar-to-base transition). |
| Thickness | Minimum thickness required for printing. | Substantial thickness that conveys robustness and quality. |
| Functional Ends | Paths end abruptly, creating steps or drops. | Paths have smooth "runouts" that blend tangentially into the next surface. |
Key Takeaway: Achieving professional quality often requires significantly more effort (e.g., 2x-3x more code) using advanced techniques like minkowski() smoothing, custom rotate_extrude profiles, and careful boolean operations to manage transitions without breaking geometry.
Don't settle for "raw geometry" if the goal is a finished product.
Last Updated: 2024-12-08