openscad

# OpenSCAD Skill Create, validate, and export OpenSCAD 3D models. Supports parameter customization, visual preview from multiple angles, and STL export for 3D printing platforms like MakerWorld. ## Prerequisites OpenSCAD must be installed. Install via Homebrew: ```bash brew install openscad ``` ## Tools This skill provides several tools in the `tools/` directory: ### Preview Generation ```bash # Generate a single preview image ./tools/preview.sh model.scad output.png [--camera=x,y,z,tx,ty,tz,dist] [--size=800x600] # Generate multi-angle preview (front, back, left, right, top, iso) ./tools/multi-preview.sh model.scad output_dir/ ``` ### STL Export ```bash # Export to STL for 3D printing ./tools/export-stl.sh model.scad output.stl [-D 'param=value'] ``` ### Parameter Extraction ```bash # Extract customizable parameters from an OpenSCAD file ./tools/extract-params.sh model.scad ``` ### Validation ```bash # Check for syntax errors and warnings ./tools/validate.sh model.scad ``` ## Visual Validation (Required) **Always validate your OpenSCAD models visually after creating or modifying them.** After writing or editing any OpenSCAD file: 1. **Generate multi-angle previews** using `multi-preview.sh` 2. **View each generated image** using the `read` tool 3. **Check for issues** from multiple perspectives: - Front/back: Verify symmetry, features, and proportions - Left/right: Check depth and side profiles - Top: Ensure top features are correct - Isometric: Overall shape validation 4. **Iterate if needed**: If something looks wrong, fix the code and re-validate This catches issues that syntax validation alone cannot detect: - Inverted normals or inside-out geometry - Misaligned features or incorrect boolean operations - Proportions that don't match the intended design - Missing or floating geometry - Z-fighting or overlapping surfaces **Never deliver an OpenSCAD model without visually confirming it looks correct from multiple angles.** ## Workflow ### 1. Creating an OpenSCAD Model Write OpenSCAD code with customizable parameters at the top: ```openscad // Customizable parameters wall_thickness = 2; // [1:0.5:5] Wall thickness in mm width = 50; // [20:100] Width in mm height = 30; // [10:80] Height in mm rounded = true; // Add rounded corners // Model code below module main_shape() { if (rounded) { minkowski() { cube([width - 4, width - 4, height - 2]); sphere(r = 2); } } else { cube([width, width, height]); } } difference() { main_shape(); translate([wall_thickness, wall_thickness, wall_thickness]) scale([1 - 2*wall_thickness/width, 1 - 2*wall_thickness/width, 1]) main_shape(); } ``` Parameter comment format: - `// [min:max]` - numeric range - `// [min:step:max]` - numeric range with step - `// [opt1, opt2, opt3]` - dropdown options - `// Description text` - plain description ### 2. Validate the Model ```bash ./tools/validate.sh model.scad ``` ### 3. Generate Previews Generate preview images to visually validate the model: ```bash ./tools/multi-preview.sh model.scad ./previews/ ``` This creates PNG images from multiple angles. Use the `read` tool to view them. ### 4. Export to STL ```bash ./tools/export-stl.sh model.scad output.stl # With custom parameters: ./tools/export-stl.sh model.scad output.stl -D 'width=60' -D 'height=40' ``` ## Camera Positions Common camera angles for previews: - **Isometric**: `--camera=0,0,0,45,0,45,200` - **Front**: `--camera=0,0,0,90,0,0,200` - **Top**: `--camera=0,0,0,0,0,0,200` - **Right**: `--camera=0,0,0,90,0,90,200` Format: `x,y,z,rotx,roty,rotz,distance` ## MakerWorld Publishing For MakerWorld, you typically need: 1. STL file(s) exported via `export-stl.sh` 2. Preview images (at least one good isometric view) 3. A description of customizable parameters Consider creating a `model.json` with metadata: ```json { "name": "Model Name", "description": "Description for MakerWorld", "parameters": [...], "tags": ["functional", "container", "organizer"] } ``` ## Example: Full Workflow ```bash # 1. Create the model (write .scad file) # 2. Validate syntax ./tools/validate.sh box.scad # 3. Generate multi-angle previews ./tools/multi-preview.sh box.scad ./previews/ # 4. IMPORTANT: View and validate ALL preview images # Use the read tool on each PNG file to visually inspect: # - previews/box_front.png # - previews/box_back.png # - previews/box_left.png # - previews/box_right.png # - previews/box_top.png # - previews/box_iso.png # Look for geometry issues, misalignments, or unexpected results. # If anything looks wrong, go back to step 1 and fix it! # 5. Extract and review parameters ./tools/extract-params.sh box.scad # 6. Export STL with default parameters ./tools/export-stl.sh box.scad box.stl # 7. Export STL with custom parameters ./tools/export-stl.sh box.scad box_large.stl -D 'width=80' -D 'height=60' ``` **Remember**: Never skip the visual validation step. Many issues (wrong dimensions, boolean operation errors, inverted geometry) are only visible when you actually look at the rendered model. ## OpenSCAD Quick Reference ### Basic Shapes ```openscad cube([x, y, z]); sphere(r = radius); cylinder(h = height, r = radius); cylinder(h = height, r1 = bottom_r, r2 = top_r); // cone ``` ### Transformations ```openscad translate([x, y, z]) object(); rotate([rx, ry, rz]) object(); scale([sx, sy, sz]) object(); mirror([x, y, z]) object(); ``` ### Boolean Operations ```openscad union() { a(); b(); } // combine difference() { a(); b(); } // subtract b from a intersection() { a(); b(); } // overlap only ``` ### Advanced ```openscad linear_extrude(height) 2d_shape(); rotate_extrude() 2d_shape(); hull() { objects(); } // convex hull minkowski() { a(); b(); } // minkowski sum (rounding) ``` ### 2D Shapes ```openscad circle(r = radius); square([x, y]); polygon(points = [[x1,y1], [x2,y2], ...]); text("string", size = 10); ```