A missing face and a duplicated face give different findings

A missing face and a duplicated face can both make a mesh unsuitable for an intended solid, but they produce different edge findings. These files change one face of the same right tetrahedron, so the expected counts can be worked out before running the checker.

How this was measured

The closed tetrahedron has four triangular faces and six edges, each shared by two faces. Removing one face leaves three edges with one incident triangle. Duplicating one face gives its three edges three incident triangles. The checker matches stored positions exactly and counts triangle incidence at each undirected edge.

Recorded output from this experiment
Measurement	Value
closed / triangles	4
closed / dimensions	10 × 10 × 10
closed / units	mm
closed / open Edges	0
closed / inconsistent Edges	0
closed / non Manifold Edges	0
closed / degenerate Triangles	0
closed / components	1
missing / triangles	3
missing / dimensions	10 × 10 × 10
missing / units	Not recorded
missing / open Edges	3
missing / inconsistent Edges	0
missing / non Manifold Edges	0
missing / degenerate Triangles	0
missing / components	1
duplicate / triangles	5
duplicate / dimensions	10 × 10 × 10
duplicate / units	Not recorded
duplicate / open Edges	0
duplicate / inconsistent Edges	0
duplicate / non Manifold Edges	3
duplicate / degenerate Triangles	0
duplicate / components	1

What the result does not establish

The counts do not identify the intended replacement surface or which duplicate should be removed. No hole filling or automatic surface selection occurs. Edge incidence also does not establish the absence of self-intersections, thin walls, or invalid vertex neighborhoods.

Try these files

These samples were created by this project and released under CC0. They contain no visitor files. Sizes and SHA-256 hashes identify the exact bytes measured in this experiment.

Ten-millimetre tetrahedron; STL itself stores no unit. (STL, 284 bytes)
SHA-256
7d98ff53aa7c0ac15350e51fc0adf77ebd39df597cac09f07269e1ff3fff9aa4
One missing tetrahedron face leaves exactly three boundary edges. (STL, 234 bytes)
SHA-256
80dec549caa7fc39c22ab0806b4e40b46835a694d5056827947ef24172a33e96
A duplicate face gives three edges a third incident triangle. (STL, 334 bytes)
SHA-256
481a849fbc081d6da134833dbe5b2c3dcb3cc37ad60d47a451855e9565e96a8a

Use this result

Versions and reproduction

Evidence generated 2026-09-05T21:13:29.140Z. The checked-in generator rebuilds the sample collection and measurements with one command:

node --experimental-strip-types scripts/build-workbench-evidence.ts

CAD source generation: scripts/build-workbench-cad.py with cadquery-ocp 7.9.3.1.1; checked-in analytic cylinder outputs. The STEP and IGES outputs are checked in so ordinary evidence rebuilds do not require Python.

@astrojs/cloudflare: 14.3.0
@cloudflare/containers: 0.3.7
astro: 7.3.1
fflate: 0.8.3
jose: 6.2.12
occt-import-js: 0.0.23
rhino3dm: 8.32.2
three: 0.185.1

Geometry source and generator SHA-256 hashes:

core/affine.ts: cff986695025f835e54c530ef654a3b7b19862d5f5feba08a361f2db708fbe65
core/bytes.ts: 850a1863a411549bbaf73e85d339dd3109fb57aca4e89e1cbeb0a06cdb3cc924
core/convert.ts: e9e96ecbb498338b85bc122a7e328ae9d96666b2dadce581e4f86e8b7b59689d
core/deflate-validation.ts: 7427464082422b2a484cb4b845e21a41dbb015ffddb83a4d1f938b6c32cb40f1
core/detect.ts: 4c64ca45732c4339749fed372b20e6996f17e1f4d307046ad71e047723ccf3e9
core/formats.ts: f037f0543d19f5ffebe97ea40450c5b646d6d5164ae4e816bf3dce6cf3685479
core/index.ts: 6dcf467a7b1952cf270fd834927404b19eb58bc6d1f2542d8c420bda90d4e3f7
core/inspect.ts: 44100ac51622e986e3ab63e49d6704dde539141454e273b76d5be70b5115a1ec
core/model.ts: bef860184a185c098d72d30a12cfaa7fe3199b96dbde0e65428b8f3bfe6c79a5
core/read/3dm.ts: f26a7d22c86dc6780ce218822eafa4cc5dbf76f35289a6266f6f2161bd84127e
core/read/3ds.ts: 0142d9f82937566220d6616c52800ffa856fff500bab3e26e90c0cdc0c6f7e32
core/read/3mf-package.ts: 11ad7a82d1dc5698412479d0c6351c5b88cfbc308ebee4a5d91fdc71d969af51
core/read/3mf.ts: 9378aa3156d5b908d4ce2ac551b76500247762de75a21b29ae0b2feb341a950e
core/read/amf.ts: b68b2de1c27d3c374ce4e2ce4215c8a6edcfbccac3e9a7ed0f623956cfe4afde
core/read/dae.ts: acf671ba4ea931ca4e958a67886978e61da9c7cb936cb835265f86d3b271b2c5
core/read/fbx-scene.ts: 89bb4fa1718fafa1e8dd8ec27197e83752fe8af7bf0c04b5d49586f611d9812d
core/read/fbx.ts: 33c87b835bf7ba11a2dd937fd78ff21a094076e9b9d95e7d24e40ea859c16bf3
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core/read/occt.ts: 1c129dc8ffb4f03bc992dd8940681acb92a4ed03271ce47485f3ac1533182117
core/read/ply.ts: 3cac9da6d62be20ae016cef751b01c14c0ebccd67d921107c56e8297835d2933
core/read/scene-validation.ts: 62e1f08faf9a9253e3b5d6c15395cbc97bc093e3867ce1aab87a3af8db704ebc
core/read/stl.ts: ac53b792bd9cb8bff4366331fa0bb49844c7d6fcf9df47819cc75544e812dec9
core/read/usdz.ts: caded369def6d998931378c616c271c565840ad280e5d797d4674f2ab1222fcb
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core/read/wrl-preflight.ts: 2a4ef48b020ef98b381ab33aa34266bb5c43de716e2e38256598d69996d235ac
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core/report.ts: 3758e6ea6f7453b23bb21682caa8828464add92d839c0cc8ae30fe46c4ca54fa
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core/units.ts: f5367c6aa2932463c90769fd0ac080e8a42aec71facf63ae32b0b08337020963
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core/workbench/tessellation.ts: f0b644e54709887e5651cdd6264e8678ed56fb9c3aebf1bd4f20124ca8cc4aea
core/workbench/workbench-capability-report.ts: 4f06ec57789c96892f7691c8c691867364ce80822f5cfc97bdcbe896f47e45d4
core/write/3mf.ts: bf9afa50480b3cb71a2a768897b7dfd5347cafa6f4d3d59550c19edf4c80446a
core/write/gltf.ts: f650b65a62d81b2c617448053726e89b4a6e0beb27955dea8e1d413d4156c0a0
core/write/obj.ts: cb0b5571284c4fe9b217a82057fd0758d406bba0fd50815313fe4ca4d4f0248c
core/write/ply.ts: cd71a26936091a3619cd67f9dc609101aea8a1ee84bc7b5c7fafcc551a328797
core/write/step.ts: 05b888318d999a952aa5d9b2bddc47a79ef9d361b6828058df4b834c6ca886fd
core/write/stl.ts: bed130d62ee6a645d79ea8fdd70441e9abb0962354963798387601f458167323
core/write/usdz.ts: 4cd8d9bf0d1aa1755c374980e5fb863b3045979e8201f8d79fc8e0857c09e962
core/xml-namespaces.ts: 10820125e1331ee730f577319faea4f279f1dd5a7b29a4bb7ec56475b7a9b0d8
core/xml.ts: b1b9e09cda3013013956dd0c0ad915dc17d6ee499d9d0ec7cd6298aa5c625184
core/zip-strict.ts: 76bdd9135e717129fa130c5597134b96056e77dbe2f3b4ed493dacd98a1ba972
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corpus/workbench/cylinder.iges: 81274edc6d86ea10fe439b7077d4a0451159d16bc9802d4c778556425631a507
corpus/workbench/cylinder.step: 0004159d7b2a121deb50aeba379c153ed27b412a8a38782a65513b3a58583a1e
package-lock.json: af6a2e949a477492e6adfcc9042705c4a785cff25715acf2ed4e85578a304627
package.json: f506303de4ba20f6ad49a2e862be535b1374ac2d6485f1875b01c04fc1426b8f
scripts/build-workbench-cad.py: 6498bdf6347ba27e6d12d3818b5793113c2e74d0d227c68ba9fab7d22dba97b1
scripts/build-workbench-evidence.ts: 68716afd03c0d6e79a051eac57cc7a37a26218b9b119857f35dfb1663ac8770a
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test/core/workbench-fbx-transforms.test.ts: 3601ac964baaae9eecda62c2301babd740a850f7e6c0d6a7569545a412105cdb
test/core/workbench-writer-transforms.test.ts: 03e8b9524d2b952f94c2ffef015d3e9b6d3a2f1882f16cb2138e96eeb5b85af0
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test/core/workbench-xml-namespaces.test.ts: de2661f4bd9414972a916eb9616c3b4f2baf4ff2a71de8268ee3a77fe8e271f5
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