Self-Intersecting Test Meshes (from libigl Tutorial Data)

This directory contains meshes from the libigl tutorial data that have been verified to contain self-intersections for demonstrating the self-intersection detection and repair nodes in ComfyUI GeometryPack.

Test Meshes

All meshes are from alecjacobson/libigl-tutorial-data and have been verified using libigl CGAL detection:

1. camelhead.off (749 KB) ✓ Verified

Intersections: 5 pairs, 6 faces affected
Classic camel head mesh from computer graphics
Minimal self-intersections - good for basic testing
Best for: Simple repair demonstrations

2. camel_b.obj (211 KB) ✓ Verified

Intersections: 23 pairs, 20 faces affected
Full camel body mesh
Moderate intersection count
Best for: Testing on organic shapes

3. cow.off (182 KB) ✓ Verified

Intersections: 83 pairs, 81 faces affected
Classic cow mesh
More complex intersections
Best for: Medium complexity testing

4. truck.obj (163 KB) ✓ Verified

Intersections: 424 pairs, 417 faces affected
Truck/vehicle mesh with many intersections
Most complex case in this set
Best for: Stress testing repair algorithms

Usage in ComfyUI

Load any mesh using the Load Mesh node
Connect to Detect Self Intersections node to visualize problems
Use Remesh Self Intersections node to attempt repairs
View results with Preview Mesh VTK (Hidable Menu) node

Detection Requirements

The self-intersection detection and repair nodes require:

libigl Python bindings (with CGAL support)
Already installed in the cad_node conda environment

Mesh Statistics

Mesh	Intersection Pairs	Affected Faces	Size
camelhead.off	5	6	749 KB
camel_b.obj	23	20	211 KB
cow.off	83	81	182 KB
truck.obj	424	417	163 KB

Verified Detection Results

When using Detect Self Intersections node, these are the confirmed results:

camelhead.off: ✓ Detects 5 intersection pairs (6 faces affected)
camel_b.obj: ✓ Detects 23 intersection pairs (20 faces affected)
cow.off: ✓ Detects 83 intersection pairs (81 faces affected)
truck.obj: ✓ Detects 424 intersection pairs (417 faces affected)

Visualization

Use Preview Mesh (VTK with Fields) node to visualize:

Scalar field self_intersecting on faces (1.0 = intersecting, 0.0 = valid)
Scalar field intersection_flag on vertices (1.0 = adjacent to intersection)
Scalar field intersection_count showing number of intersecting faces per vertex

Repair Options

Remesh Self Intersections node parameters:

detect_only=False - Actually remesh (subdivide intersecting triangles)
remove_unreferenced=True - Clean up unused vertices
extract_outer_hull=False - Extract outer hull for manifold result (slow but clean)
stitch_all=True - Attempt to stitch boundaries

Scripts

test_intersections.py - Script to test meshes for self-intersections
intersection_test_results.txt - Test results log

Notes

These are real-world meshes from graphics research, not synthetic test cases
Complexity ranges from minimal (camelhead) to significant (truck)
All meshes successfully tested with libigl CGAL detection
Original source: libigl tutorial data repository

Attribution

Test meshes sourced from libigl tutorial data (Alec Jacobson et al.)

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