Why my BSP box can't cast shadow on anther BSP box?

As the pic show ,I have putted a BSP box in "Lightroom " demon ,and one of the BSP box can cast shadow on the floor ,but the another one can’t cast shadow on BSP box which is under it .Why?


Hey ChenJuye-

Are you rebuilding lighting after adding the second bsp to your room? Anytime the BSP is moved or resized, lighting will need to be rebuilt for the shadows to appear correctly.


I add a model in to my scence,then build the lighting,but still noshadow

Which version of the engine are you working in? Working in 4.5.1 I was able to add a piece of bsp then build lighting. I added another bsp on top of the first and built lighting again and the shadow of the second showed up on the first.