Crate mesh_shell 

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();

Structs

BoundaryAnalysis

Result of boundary topology analysis.

BoundaryLoop

A boundary loop representing a single closed boundary in the mesh.

RimResult

Result of rim generation.

SdfOffsetParams

Parameters for SDF offset operation.

SdfOffsetResult

Result of SDF offset operation.

SdfOffsetStats

Statistics from SDF offset operation.

ShellBuildResult

Result from ShellBuilder containing the generated mesh and statistics.

ShellBuilder

Fluent builder for shell generation.

ShellGenerationResult

Result of shell generation.

ShellParams

Parameters for shell generation.

ShellRepairResult

Result of shell auto-repair operation.

ShellValidationResult

Result of shell validation.

Enums

ShellError

Errors that can occur during shell operations.

ShellIssue

Issues that can be found during shell validation.

WallGenerationMethod

Method for generating the outer surface of the shell.

Functions

analyze_boundary

Analyze boundary topology of a mesh.

apply_sdf_offset

Apply SDF-based offset to create a new mesh with variable offsets.

generate_rim

Generate rim faces to connect inner and outer surfaces at boundaries.

generate_rim_advanced

Generate rim faces with full boundary analysis and reporting.

generate_rim_for_sdf_shell

Generate rim faces for SDF-based shell where inner and outer surfaces have different vertex counts and no 1:1 correspondence.

generate_shell

Generate a printable shell from the inner surface.

generate_shell_no_validation

Generate a shell without automatic validation.

generate_shell_with_progress

Generate a printable shell with progress reporting.

repair_shell

Attempt to automatically repair minor issues in a shell mesh.

validate_and_repair_shell

Validate and optionally repair a shell mesh.

validate_boundary_for_rim

Validate that a mesh’s boundaries are suitable for rim generation.

validate_shell

Validate a shell mesh for 3D printing suitability.

Type Aliases

ShellResult

Result type alias for shell operations.