GI cache area

[N-drju]

I've been wondering - is it necessary to calculate a GI cache of the entire render? Or is it fine to render just part of the image in order to obtain the lighting cache file?

I always render the entire image to produce GI cache files but just recently started to have doubts... Perhaps a smaller crop would do and it's all just a waste of time otherwise?

[Dune]

You have to calculate the light from all directions for GI, so from sky but also from reflected snow or so, so I think it's very wise to take the whole thing. You could reduce size of course, just for the GI.

[N-drju]

You could reduce size of course, just for the GI.

Maybe. Though I'm afraid this may cause differences between the crops.

I tried calculating GI cache with a smaller version of a big render, but I had visible differences on a building wall - where the crop edges met. I'm not sure if this was it however - this render could not be fixed at all, no matter what settings were used.

Nevermind though - the point is I'm afraid this may cause problems, though I'll check it again when the new CPU arrives!