That's progress, how pleasing.
Talking about the environment map, it should be possible to get more of it without changing the ressource.
dechrigi wrote:For the moment I just tried turning up the gain
That's the first step indeed. There is now sufficient light coming from the env, as verified by the linear/camera tonemapping.
Now, did this first step enhance shadows ? I don't think so, only relatively to the exposure level, not by increasing the discrepancy of the source's powers. At this point you could have nearly the same result with a white-ish background I think.
What is all this about ? Nothing, just an introductory movement: you may want to decrease the environment texture C parameter in order to set the black point muuuch darker. Eventually you will have to counter-balance the global energy loss by increasing the gain (B parameted)
proportionally. Not: equally, as B is a multiplier and C a threshold for the lowest value; it sums to the B multiplied value, and actually the threshold must be set lower in order to bring burned out regions back in the middle levels. Then you will enjoy your map to a larger extent !
That's a bit of a circumvolutive explanation, hopefully it makes sense
PS: in fact it should be possible to compress the full dynamic range to the film capacity with only the B and C parameters. Rethorically speaking, as this would reduce again the range to about nothing.