Booleans - OpenGeometry

solid.operate(kind, { tools, instances? }) changes the target solid once:

Kind	Result
`OG_OPERATION_SUBTRACT`	The target minus every tool
`OG_OPERATION_UNION`	The target joined with every tool
`OG_OPERATION_INTERSECT`	What the target and the tools share

tools is one to a hundred solids. The tools stay separate, live solids. Moving or disposing a tool later does not change the target. A tool is drawn only if you add it to the scene.

Cut openings into a wall

import {
  OpenGeometry,
  Solid,
  Wire,
  OG_OPERATION_EXTRUDE,
  OG_OPERATION_SUBTRACT,
  OG_PRIMITIVE_CUBOID,
  OG_PRIMITIVE_RECTANGLE,
  OG_TRANSFORM_TRANSLATE,
} from 'opengeometry';

await OpenGeometry.create(
  { wasmURL: '/opengeometry_bg.wasm' },
  { workerURL: '/tessellation-worker.js' },
);

const wall = new Solid(OG_OPERATION_EXTRUDE, {
  profile: new Wire(OG_PRIMITIVE_RECTANGLE, { width: 6, breadth: 0.2 }),
  distance: 3,
});
const door = new Solid(OG_PRIMITIVE_CUBOID, { width: 0.9, height: 2.1, depth: 0.4 });
door.transform(OG_TRANSFORM_TRANSLATE, { offset: [-1.5, 0, 0] });
const pane = new Solid(OG_PRIMITIVE_CUBOID, { width: 1.2, height: 1.2, depth: 0.4 });
pane.transform(OG_TRANSFORM_TRANSLATE, { offset: [1.2, 0.9, 0] });
wall.operate(OG_OPERATION_SUBTRACT, { tools: [door, pane] });
console.log(wall.getReport()?.report.operation, wall.validity().valid);

An arched opening

Make an arch as one closed profile, a straight sill, two jambs and a half-circle head, and extrude it through the wall. This works through a straight or a curved wall:

import {
  OpenGeometry,
  Solid,
  Wire,
  OG_OPERATION_EXTRUDE,
  OG_OPERATION_SUBTRACT,
  OG_PRIMITIVE_PROFILE,
  OG_PRIMITIVE_RECTANGLE,
} from 'opengeometry';

await OpenGeometry.create(
  { wasmURL: '/opengeometry_bg.wasm' },
  { workerURL: '/tessellation-worker.js' },
);

const wall = new Solid(OG_OPERATION_EXTRUDE, {
  profile: new Wire(OG_PRIMITIVE_RECTANGLE, { width: 4, breadth: 0.3 }),
  distance: 3,
});
const arch = new Wire(
  OG_PRIMITIVE_PROFILE,
  {
    start: [-0.3, 0.4],
    segments: [
      { to: [0.3, 0.4] },
      { to: [0.3, 1.5] },
      { to: [-0.3, 1.5], arc: { center: [0, 1.5], counterClockwise: true } },
      { to: [-0.3, 0.4] },
    ],
    closed: true,
  },
  { plane: { origin: [0, 0, -0.5], normal: [0, 0, 1], xDirection: [1, 0, 0] } },
);
const cutter = new Solid(OG_OPERATION_EXTRUDE, { profile: arch, distance: 1 });
wall.operate(OG_OPERATION_SUBTRACT, { tools: [cutter] });
console.log(wall.getReport()?.handlers);

Use one arch-profile prism. A rectangle prism plus a half-cylinder, whose sides touch along the cylinder, can fail through a curved wall.

The report

solid.getReport() returns the report of the last boolean, or null:

report.operation: 'union', 'intersection' or 'subtraction'.
report.face_mappings: for each face of the inputs, the faces of the result that came from it.
report.contacts and report.coincident: where the inputs touch.
handlers: the kernel methods that made the result.
revision: the shape revision of the result.

A rebuild or a mirror clears the report.

When a boolean is refused

A refused call throws an OGError and leaves the target as it was. details says which methods were tried:

import {
  OGError,
  OpenGeometry,
  Solid,
  OG_OPERATION_SUBTRACT,
  OG_PRIMITIVE_CONE,
  OG_PRIMITIVE_CUBOID,
} from 'opengeometry';

await OpenGeometry.create(
  { wasmURL: '/opengeometry_bg.wasm' },
  { workerURL: '/tessellation-worker.js' },
);

const cone = new Solid(OG_PRIMITIVE_CONE, { radiusBottom: 1, radiusTop: 0, height: 1 });
const box = new Solid(
  OG_PRIMITIVE_CUBOID,
  { width: 0.5, height: 0.5, depth: 0.5 },
  { plane: { origin: [0, 0.8, 0] } },
);
try {
  cone.operate(OG_OPERATION_SUBTRACT, { tools: [box] });
} catch (error) {
  if (error instanceof OGError)
    console.log(error.code, error.details.families, error.details.attempted);
}

CoverageGap: the kernel has no method for this pair yet. details.families names the pair, such as ['cone or frustum', 'cuboid'].
UnresolvedIntersection: the kernel could not trace the intersection.
toolIndex and ogIds name the tool that failed.

Some refused cuts are slow, because the kernel tries several methods before it refuses.

Instances

If the target’s shape is shared, pass { instances: 'all' } to cut every instance, or call makeUnique() first. Otherwise the call throws SharedShape. A tool may not be the target or have the target’s shape.

​Cut openings into a wall

​An arched opening

​The report

​When a boolean is refused

​Instances

Cut openings into a wall

An arched opening

The report

When a boolean is refused

Instances