It is similar to 'power' in that it controls the 'brightness' of the emitter using real-world values. For example, the emission of most light bulbs is printed on the box in lumens.Pibuz wrote: 1. what is emission scale?
I'm not sure....if you take a look at the Render Log in Indigo when using Sun and Sky, it does show what luminance values are being used for the environment.2. what is the numeric value of the emission scale of sun and sky?
This corresponds to the previous default in older SkIndigo versions of a 100W bulb with an efficacy of 17.5 lm/W. To get lumens, multiply efficacy (lm/W) by number of watts.3. why a default emitter material is set to 1750 lm by default?
Try not to get overwhelmed with emission scale. Just think of it as a multiplier for the emission. Using layers is recommended for greater control. It is true that more samples are given to emitters with greater luminance so a useful trick for getting emitters to converge faster (when combined with sun/sky) is to crank up the emission scale value so that it is similar to the value for sun/sky and then scale it back down using the light layer gain control within Indigo.4. how do I work with the emission scale parameter? I thought that parameter was introduced to make each light layer's calculation more handy: if I set same emission scale scale to two different materials, the one which has more power takes more CPU power. Is this correct? But..
Hopefully I have already answered this indirectly. There is still a gain parameter when setting up a blackbody spectrum but I think Indigo over-rides this value using whatever emission scale you have set.5. where do I set the power of the emitters? Where is the gain parameter gone? does it still matter?
A tutorial on this subject is would definitely be helpful. I have attached a sample SKP scene that should help a bit.