loaded from the content (Teapots_PortalOFF.lws and Teapots_PortalON.lws)tried here: LightPortals.zipThis example can be
For copyright reasons, a gradient has replaced the HDR image for this scene. The effect is more interesting with a proper HDR image.
Area and NGon lights can be used as portals. Portal lights are guides placed in indoor scenes that help the renderer to concentrate environment lighting through openings like small windows.