To Assign Environment Maps to a DGN File

Select the Environment Maps tool.
The Environment Manager dialog opens.
Confirm that Enable is checked.
From the option menu, select Image Cube.
Click the Browse For File icon for the face of the cube that is required.
The Open file dialog opens.
Select an image file.
Click the Open button.
If no image files have been applied previously, the selected file is applied to all faces of the environment cube.

If image files have been applied previously, the selected file is applied only to the selected face.
(Optional) To apply a different image or images to some of the other faces of the environment cube, click the Browse For File icon for the required face and select the image file as above.
Click OK.
The Environment Manager dialog closes.