Shell generation around 3D meshes using SDF-based offset.

This crate provides tools for generating printable shells around 3D meshes using signed distance field (SDF) based offset techniques.

Features

• SDF-based offset: Robust offset that avoids self-intersections
• Variable offset: Per-vertex offset values for complex shapes
• Shell generation: Create watertight shells with walls
• Rim generation: Clean boundary edges connecting inner and outer surfaces
• Builder API: Fluent builder pattern for ergonomic configuration

Quick Start with ShellBuilder

The recommended way to generate shells is using the [ShellBuilder]:

use mesh_repair::Mesh;
use mesh_shell::ShellBuilder;

let mesh = Mesh::load("scan.stl").unwrap();

// Simple: generate shell with defaults
let result = ShellBuilder::new(&mesh)
    .offset(2.0)           // 2mm outward offset
    .wall_thickness(2.5)   // 2.5mm walls
    .build()
    .unwrap();

result.mesh.save("shell.3mf").unwrap();

Advanced Configuration

use mesh_repair::Mesh;
use mesh_repair::progress::ProgressCallback;
use mesh_shell::ShellBuilder;

let mesh = Mesh::load("scan.stl").unwrap();

let callback: ProgressCallback = Box::new(|progress| {
    println!("{}%: {}", progress.percent(), progress.message);
    true // continue
});

let result = ShellBuilder::new(&mesh)
    .offset(3.0)
    .wall_thickness(2.0)
    .voxel_size(0.5)       // Fine resolution
    .high_quality()         // SDF-based walls
    .use_gpu(true)          // GPU acceleration
    .with_progress(callback)
    .build()
    .unwrap();

Low-Level API

For more control, use the low-level functions directly:

use mesh_repair::Mesh;
use mesh_shell::{apply_sdf_offset, generate_shell, SdfOffsetParams, ShellParams};

let mut mesh = Mesh::load("scan.stl").unwrap();

// Set offset values on vertices
for v in &mut mesh.vertices {
    v.offset = Some(2.0);
}

// Apply SDF offset
let params = SdfOffsetParams::default();
let result = apply_sdf_offset(&mesh, &params).unwrap();

// Generate shell with walls
let shell_params = ShellParams::default();
let (shell, stats) = generate_shell(&result.mesh, &shell_params);

shell.save("shell.3mf").unwrap();