Resources Numerical accuracy

Equality comparisons

Where the code asks whether two decimal numbers are exactly equal. A floating-point result can differ from another in the last digit after a few transformations, so a mesh run through several of them can change the length of an edge, or miss a match. Compare with < or > where a range is meant, and with a documented epsilon where equality is.

316 comparisons to look at
149 files
175 likely to matter (against a decimal, or two computed values)
Scanned November 6, 2026

These are places worth checking, not confirmed bugs. The scan reads how the code is written, not what it is meant to do, so some entries are fine as they are: a test against exactly 0 is often a deliberate guard against dividing by zero. It skips text, counts and indexes, and any comparison it cannot be sure involves decimal numbers, so there are likely more in the code than are listed here.

Against 0 addons/trusscraft/lib/design.js:130 in designTruss CadCraft, BimCraft, ModelCraft, PartCraft
```
const closed = g.profile ? g.nodes.find((n) => n.x === 0 && n.z === 0) : true;
```
=== in n.x === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Reviewed: Truss member forces and timber checks.
Against 0 addons/trusscraft/lib/design.js:130 in designTruss CadCraft, BimCraft, ModelCraft, PartCraft
```
const closed = g.profile ? g.nodes.find((n) => n.x === 0 && n.z === 0) : true;
```
=== in n.z === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Reviewed: Truss member forces and timber checks.
Against 0 lencalc.js:130 in term CadCraft, ModelCraft, MarkupCraft, TakeoffCraft, CivilCraft, DetailCraft
```
if (o.t === '/' && b.v === 0) throw new CalcError('divide', o.pos);
```
=== in b.v === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Reviewed: Arithmetic on typed lengths.
Against 0 usd/earcut.js:52 in filterPoints CadCraft, BimCraft, ModelCraft, TakeoffCraft, CivilCraft, DetailCraft, PartCraft
```
if (!p.steiner && (equals(p, p.next) || area(p.prev, p, p.next) === 0)) {
```
=== in area(p.prev, p, p.next) === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Reviewed: Polygon triangulation (ear clipping).
Against 0 usd/usda-read.js:476 in component CadCraft, BimCraft, ModelCraft, TakeoffCraft, CivilCraft, DetailCraft, PartCraft
```
if (c.k === 'num') { this.i++; return c.v !== 0; }
```
!== in c.v !== 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Reviewed: Floats read from USD files.
Against 0 earcut.js:51 in filterPoints ModelCraft
```
if (!p.steiner && (equals(p, p.next) || area(p.prev, p, p.next) === 0)) {
```
=== in area(p.prev, p, p.next) === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Not in the register.
Against 0 io/3dm/earcut.js:52 in filterPoints ModelCraft
```
if (!p.steiner && (equals(p, p.next) || area(p.prev, p, p.next) === 0)) {
```
=== in area(p.prev, p, p.next) === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Not in the register.
Against 0 io/3dm/geom.js:155 in rec ModelCraft
```
if (chordDev(pm, pa, pb) > tol || chordDev(q1, pa, pb) > tol || chordDev(q3, pa, pb) > tol || (depth < 2 && dist(pa, pb) === 0 && dist(pm, pa) > tol)) {
```
=== in dist(pa, pb) === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Reviewed: 3DM curves and surfaces: points on them.
Against 0 io/3dm/tess.js:245 in emit ModelCraft
```
if (ar === 0) { const n = cross(sub(pos(c), pos(a)), sub(pos(d), pos(a))); if (len(n) === 0) return; }
```
=== in len(n) === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Reviewed: 3DM surfaces into triangles.
Against 0 nurbs/construct.js:86 in revolve ModelCraft, PartCraft
```
if (V.len(Z) === 0) fail('nurbs.err.axis');
```
=== in V.len(Z) === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Reviewed: Surfaces from curves: extrude, ruled, revolve and loft, Fitted curves and surfaces: sweeps, networks, Coons patches, offsets, rebuilds and extensions.
Against 0 tools.js:727 in value ModelCraft
```
if (!Number.isFinite(deg) || deg === 0) return false;
```
=== in deg === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Not in the register.
Against 0 tools.js:1138 in pickPoint ModelCraft
```
this.k = 1 / Math.max(len(this.T.localDir(this.n)), 1e-9) === 0 ? 1 : len(this.T.localDir(this.n));
```
=== in 1 / Math.max(len(this.T.localDir(this.n)), 1e-9) === 0. Usually fine as a guard against dividing by zero; check it is not meant to catch a near-zero value too. Not in the register.