well, you can certainly use a simple white map, but the texture i provided is slightly more complex. it’s more like a gradient, so that each panel emits more light from its center than from the edges, since that’s the way it works in real life.
if you keep on getting black renders, you might want to check if your camera is inside or outside the box. if it’s outside, nothing from the inside will be seen. also check that final gather is turned on or the box won’t emit any light.
good luck!!






