Merging display layers or render layers when importing files

User Guide > Rendering and Render Setup > Rendering > Visualize and render images > Visualize scenes and render images > Work with render layers >

When you import a file into Maya, you can merge the display layers or render layers from the imported file into your current scene. You can merge layers of the same name or of the same index number.

For example, if you choose to merge display layers by name, then all objects on the layer named MyLayer of the imported file will be merged with objects on the layer named MyLayer of your current scene. The merged layer will retain its name MyLayer.

To merge display/render layers by layer name

Ensure that the layers that you wish to merge share the same layer name.
Click on the Display/Render radio button in the Render Layer Editor to view the desired layers.

To change the layer name, double-click the layer for the Edit Layer dialog box to appear.
Select Window > Settings/Preferences > Preferences, click the Files/Projects category, and in the Display Layer section (or Render Layer section), select By Name.
Import the file by selecting File > Import.

To merge display/render layers by layer number

Ensure that the layers that you wish to merge share the same layer index number.
Click on the Display/Render radio button in the Render Layer Editor to view the desired layers.

To edit the layer index number, right-click the desired layer and select Attributes from the right-mouse menu to display the display/render layer’s Attribute Editor. Enter the layer number in the Number attribute.
Select Window > Settings/Preferences > Preferences, click the Files/Projects category, and in the Display Layer section (or Render Layer section), select By number.
Import the file by selecting File > Import.