Solid modeling

How the precision is kept

Booleans run in manifold-3d 3.5.4, whose result is a closed, manifold solid by construction. Volume and surface area come straight from the kernel. The vertex positions read back for named faces, edges and the display are 32-bit.

Open item. Read positions back in 64-bit wherever a measurement uses them.

2 calculations in 1 source file. The code is read from the released app when this page loads. It is the calculation people run, not a copy kept for this page.

stats = {
  volume: b.volume(), area: b.surfaceArea(), genus: b.genus(), tris: ntri,
  bodies: (() => { const parts = b.decompose(); const n = parts.length; parts.forEach((p) => p.delete()); return n; })(),
  bbox: { min: [...bb.min], max: [...bb.max] },
};

const gm = b.getMesh();
const np = gm.numProp;
const nv = gm.vertProperties.length / np;
const positions = new Float32Array(nv * 3);
for (let i = 0; i < nv; i++) for (let k = 0; k < 3; k++) positions[i * 3 + k] = gm.vertProperties[i * np + k];

In detail

Method

Each feature builds tools that are added to or cut from the body in order by manifold-3d 3.5.4, compiled to WebAssembly. Every triangle of the result knows which feature made it.

Number types

32-bit arrays for the vertex positions read back from the kernel, 32-bit integers for triangles. Volume and surface area are computed inside the kernel and returned as 64-bit numbers.

Checked by

The PartCraft test suite builds real parts with the same code the page runs.

Limits

This is a mesh kernel: curved faces are facets, and fillets, chamfers, shells and drafts are built approximately.

Approach: 32-bit step, flagged

One step stores or exchanges 32-bit values that reach a number a person reads. It is listed here with its open item, and the step is either moved to 64-bit or the app will warn where the number is read.

Every policy that takes this approach