Defines a single object that combines one or more objects.

Using blocks lets you:

  • Create parts libraries.

  • Update all instances by modifying the block definition.

  • Keep a smaller model size by using block instances instead of copying identical geometry.

  • Use the BlockManager
    command to view information about the blocks defined in the model.

  • Use the Insert
    command to place block instances into your model, which scales and rotates the instance.

To define a block

  1. Select

    the objects.

  2. Pick

    a base point for the block.

  3. This is the point around which the instance will be located, scaled, and rotated when it is inserted.

    A control point is placed at the base point of the block.

  4. Type a name and description for the block definition properties.

  5. You can also add a URL to the block.

    The objects you selected are converted into a block instance.

To redefine a block

  • Follow the steps for defining a block and re-use the same block name.

Block Instances and Layers

The properties of the geometry (curves, surfaces, etc.) that are contained in the block instance are controlled either by the layer properties or object properties of the geometry itself. Block instances that you insert to the model insert onto the current layer and can be moved to any other layer. There is no relationship between the block instance’s layer and the geometry contained in the block. For example, the block geometry does not change to match the layer color onto which the block instance is inserted.

When the block contains objects on a specific layer, turning that layer off will turn off only the objects on that layer. However, if the layer the block instance is inserted on is turned off, all of the objects will disappear.


  1. Create an object on Layer 01.

  2. Make this object into a block.

  3. Make Layer 02 current.

  4. Insert an instance of the block you just made.

  5. Turn off Layer 02.

  6. The block instance placed on Layer 02 disappears because the (invisible) insertion point of the block instance is on Layer 02, but the original block instance was inserted on Layer 01 when it was created, so it does not turn off.

  7. Turn Layer 02 back on and make it current.

  8. Make some new geometry on Layer 02.

  9. Make this into a block.

  10. Make Layer 01 current and insert an instance of this new block.

  11. Turn off Layer 02.

  12. Because the geometry is on Layer 02, the block instance you inserted onto Layer 01 disappears. The original block instance also disappears because both the geometry and the insertion point are on Layer 02.

Two factors are involved: the layer or layers of the original geometry (there is nothing to stop blocks from containing objects on different layers) and the invisible insertion point of the block instance, which can be on any layer.

Locking Layers

When you lock a layer, only the layer that contains the insertion point of the block instance is locked. If a block has objects that are on the locked layer, but the block instance insertion point is not on that layer, the object itself is not locked because the controlling factor is the layer of the block insertion point.


objects will not be maintain their grouped status inside a block.


Rhinoceros Block Blocks

Block > Block Definition

Rhinoceros Menu2 Blocks

Edit > Blocks > Create Block Definition

Rhinoceros key 008 Blocks


+ B

Rhinoceros Gray Book Open Blocks Related topics…


Manages the block definitions in the model.


  • In the Block Manager dialog box, set block properties.

Block Definition list


Displays a list of block definitions in the model.

Link Status

Displays the status of block instances linked to external files.

Up to date

The block definition and link file match.

Linked file is older

The linked file is older than the block definition.

Linked file is newer

The linked file is newer than the block definition.

Linked file is different

The linked file and the block definition do not match.

Not linked

The block definition was not created by importing a file.

File not found

The file that was used to create the block definition cannot be found.

The missing block location is marked with a text dot object listing the missing block name.

To resolve the issue

  • Click the Properties button to locate the missing block file, and then click the Update button to restore the missing block.

  • Or, click the Delete button to remove the link.

Link File Name

The name of the file that was imported to create the block definition.

Update linked and embedded blocks when opening this file


Updates externally linked blocks automatically.


Prompts to update externally linked blocks.


Never updates externally linked blocks.

Hidden blocks

Show hidden block definitions

Allows display of block names beginning with “*”.




Exports the block’s component objects to a file.


Delete all instances of the selected block.


Redefines the block definition to match the original imported file. Use the information in the Link Status column to determine if the file needs to be updated.

Used by

Lists block definitions that contain the selected block as a nested block.


Counts the number of instances of the block in the model. Nested instances are not included in the count.

Block Definition Properties

Block Definition Name

The block name.

File name

The external file name linked to the block definition.


Change the name or location of the external file.


Break the link to the external file. The block becomes embedded.

External File

For a file inserted as block instance.


Insert geometry into the current file. This will not update if the external file changes.

Link and embed

Insert geometry into the current file and maintain a link to the external file. Linked geometry can be updated when the external file changes. See: BlockManager
. If the external file cannot be located, the geometry is still defined in the current file.


Maintain a link to the external file only. Linked geometry is updated when the external file changes. See: BlockManager
. If the external file cannot be located, the geometry will not appear in the current file.

Do not read linked blocks from this file

If the external file contains linked blocks, these will not be inserted.

Use relative file path

The relative path to the external file.


Optional description.


Optional web link.




Rhinoceros BlockManager Blocks

Block > Block Manager

Rhinoceros Menu2 Blocks

Edit > Blocks > Block Manager

Rhinoceros Gray Book Open Blocks Related topics…


Sets a base point in a model that is used when inserting the modeling as a block definition.


  • Pick

    a location.

By default the base point in any model is 0,0,0.

The ModelBasepoint command lets you set that point. The set base point has no effect in the current file, it is only a handle when inserting it into another Rhino model.

Rhinoceros ModelBasePoint Blocks

Block > Set Model BasePoint

Rhinoceros Menu2 Blocks


Rhinoceros Gray Book Open Blocks Related topics…