reusing GI calculations

[cheerioboy]

To what extent can you modify your scene, and still use a previous GI calculation? I only save GI calculations for animations, but I'm curious if there might be a way for me to cut down on the time during render tests if I could reuse a GI calc, and still tweak material subdivs or light subdivs. Or does that still require a new GI calculation for proper results?

any insight into this?

[Dariusz Makowski (Dadal)]

Its quite simple.

GI.
U change geometry - need new GI
U change diffuse - need new GI
U change reflection - need new GI
U change refraction - need new GI.

U can change bump and dont need new GI
U could tweak-fine tune displacement - and it might work.

And thats it I guess...?