SuspendUpdates
From Director Online Wiki
Set sprite(<3DspriteNum>).suspendUpdates to TRUE to prevent the sprite from being updated as part of the normal screen redraw operations.
A disadvantage of this is that trails will be created in the 3D sprite if you drag another window over the top of it.
To resume normal redraw behavior, set sprite(<3DspriteNum>).suspendUpdates back to FALSE, its default value.