I have this library scene which is full of instanced group of the same model. The vert count says only 58, but when actually rendering it shoots to 1.7M due to all the books. However, the rendering is fast because Blender seems to exclude unseen objects.
However, when I turn on Indirect Lighting because I want it's effect, now the rendering time is exponentially higher. It seems to be longer proportional to vert count, even occluded ones.
Hiding some model is not an option since the camera will move around and eventually will reach the hidden part that I set. (Imagine a zooming all the way on this corridor)
Is there any solution to make indirect lighting calculate only the relevant model that matters in the current frame automatically, like the normal rendering without indirect lighting?
In this scene I even have a mist, so technically I can exclude everything further than the visible range. I thought things like setting camera's far clipping plane can help excluding things for Blender to consider but that is not the case. Rendering time is the same even with far plane as low as 100.