Paste Options - In the Menu Bar, click Edit > Preferences, then on the left side of the dialog box, select Copy and Paste.
Paste Touch Sensors - Pastes all touch sensors from the copied nodes and their subtrees. Before doing this, check whether you want this before continuing.
Paste Animation Curves - Pastes all animation curves from the copied nodes and their subtrees. Before doing this, check whether you want this before continuing.
Merge Materials - Merges all materials with the scene's material pool. Before doing this, check whether materials from the copied nodes and their corresponding subtrees should be merged with the scene's material pool or not. All materials are compared with the pool materials. If all properties of a material are equal with one in the pool, including its environment, it is not added as an additional material. Instead the material from the pool is used. If a material has no counterpart in the pool, it is added. If this is unchecked, all materials are added to the pool, which may result in copies of materials.
Environments - Merge with Scene: Merges the environments with the environments in the scene, using the same strategy as merge materials.
Use Scene Default - Discards all environments and sets the default environment of the scene to all materials.
Note: If this option is selected, the material comparison assumes the default environment as the environment set for the copied materials.
Add Copy to Scene - Adds a copy of the environment to the material pool. If the environment is a switch, all environments of the switch are copied, as well. This option is only available when materials are not merged, so the Merge Materials option must be toggled off.
Show Dialog - When checked, the dialog will not appear again and the copy paste will apply the last given settings.