Duplicating Objects

Use

When you duplicate an original object, it is either ‘instanced’ or copied depending on the method you use.

Features

Copying

Copying creates an additional object that is identical to the original, but the mesh is no longer shared between the objects. Therefore, the actual geometry of the object is saved multiple times. These objects are now called the ‘original objects’.

Instancing

When a model contains multiple objects with identical geometric meshes, the actual geometry of the object is saved only once; the ‘original object’. The object is then duplicated as many times as the object is used in the model, for the different locations and orientations throughout the scene.

‘Instanced objects’ have the same mesh as the original, but a different transformation matrix (position, orientation, and scale). For example, if a spark plug is used eight times in a V8 engine, seven instances are created that point to the original object and its geometry.

Instancing objects reduces the size of the file, helps save memory, decreases render times, and increases the data transfer rate.

When you edit the geometry of an instanced object, all the objects based on it are updated to reflect the changes. Transforming, applying modifiers, and adding animation to individual objects does not modify any other instances of that object.

As all instanced objects point to the same polygonal mesh, you can see which mesh this is in the Object Properties window.