InstanceDefinitions, References, and Objects

Hi All,

I’m trying to finally wrap my head around the blocks in rhinocommon and I’m not quite sure I understand all the different terms. Below is my understanding of the following terms. Can somebody confirm if I have the correct understanding?

InstanceDefinition – a block in the Instance Definition table. This block lives in the rhino file but not in model space.

InstanceObject – the actual block placed in model space.

InstanceReference – a reference to the block placed in model space

InstanceDefinitionGeometry – the geometric elements of the block (not placed in model space) definition

InstanceReferenceGeometry – the geometric elements of the block placed in model space

How about this?

Instance Definition - The definition of an Instance, or Block. An Instance Definition is simply a collection of one or more objects (i.e. Instance Definition Geometry) that has a name. Instance Definitions are stored in the Instance Definition Table, which is store in the document.

Instance Reference - A reference to an Instance Definition, along with a transformation to apply to the definition.


Thanks Dale for helping clarify. Cheers!