Blocks

1. What is a Block? (The Master Definition)

A Block (DucBlock) is an authoritative, reusable definition of a set of elements.

• Single Source of Truth: There is only ONE master Block definition of a kind stored in the document’s block registry.
• Blueprint: A Block defines the geometry, visual styles, and spatial arrangement of a reusable component.

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2. What is a Block Instance?

A Block Instance (DucBlockInstanceElement) is a live spatial reference placed on the drawing canvas that derives its geometry and layout from a master Block definition.

• One-to-Many Relationship: While a document contains only one master Block definition, multiple instances can be placed across the canvas relative to that single block.
• Automatic Synchronization: When the master Block definition is updated, all live instances will automatically synchronize to reflect the design change instantly.

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3. Instance Overrides

• Granular Customization: An instance can override specific properties of its inner elements without detaching from the master Block.
• Selective Synchronization: When the master Block is modified, all non-overridden properties of every instance update automatically, while individual instance overrides are preserved.

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4. Duplication Arrays

• Pattern-Based Replication: A single block instance can define a linear or grid duplication array with specified counts and spatial offsets.
• Unified Management: The entire array is managed as a single logical entity, automatically rendering repeated instances across calculated spatial offsets while remaining fully synchronized with the master Block definition.

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5. Block Collections

As engineering projects grow to contain hundreds of reusable blocks, organizing these assets becomes critical.

A Block Collection (DucBlockCollection) is an organizational folder or pocket of blocks:

• Not Canvas Groups: Unlike visual groups on the canvas (groupIds), a Collection is a structural data organization hierarchy within the document container.
• Nested Folder Structures: Collections can contain blocks and sub-collections, allowing engineering teams to build clean, categorized asset libraries directly inside the .duc file.