BlockAnnotations

Global drawing system that manages block insertions across all TechnicalDrawing instances.

Extends

• AnnotationSystem<BlockAnnotationsSystem>

Implements

• Disposable

Constructors

new BlockAnnotations()

new BlockAnnotations(components): BlockAnnotations

A block is a named, reusable geometry definition (e.g. a furniture symbol or a detail imported from a DXF). Multiple insertions of the same block share the same THREE.BufferGeometry, so only the transform (position, rotation, scale) differs per instance.

Register via TechnicalDrawings.use:

const blocks = techDrawings.use(BlockAnnotations);

Typical workflow:

// 1. Project external geometry to drawing space
const projected = TechnicalDrawing.toDrawingSpace(ifcLines, drawing);

// 2. Register the block definition (global — do this once)
blocks.define("CHAIR", { lines: projected.geometry });

// 3. Insert on any drawing
blocks.add(drawing, { blockName: "CHAIR", position, rotation: 0, scale: 1, style: "default" });

Parameters

Parameter	Type
components	Components

Returns

BlockAnnotations

Overrides

AnnotationSystem<BlockAnnotationsSystem>.constructor

Properties

definitions

readonly definitions: DataMap<string, BlockDefinition>

Named block definitions in block-local XZ space. Register via define. Geometry is shared across all drawings and insertions.

Methods

define()

define(name, definition): void

Registers a block definition by name (global — not tied to any drawing). All geometry must be in block-local XZ space (Y = 0). Use TechnicalDrawing.toDrawingSpace to project external geometry first.

Replaces any existing definition with the same name without disposing the old geometry.

Parameters

Parameter	Type
name	string
definition	BlockDefinition

Returns

void

---

pick()

pick(ray, threshold): null | string

Overrides the base pick to use the correct LineSegments.raycast (pair-based) rather than THREE.Line.prototype.raycast (continuous-line).

Parameters

Parameter	Type	Default value
ray	Ray	undefined
threshold	number	0.05

Returns

null | string

Overrides

AnnotationSystem.pick