[Radiance-general] the reference illuminance?

[Lars O. Grobe]

> The tested illuminance value of the indoor point in the evening is 20 lux, but
> the simulated value is 0.0 lux, so how to adjust the calculated value to 20
> lux?
>   
I do not know the parameters you used, but 0,0,0 means that most
probably you have no ambient calculation. As most parts of your room
will receive only indirect illumination, this will result in zero. Try
setting -ab to 2. To understand the effect of -ab for your scene, render
images of your room using -ab 0, -ab 1, -ab 2, -ab 3 with -av set to 0 0
0 for all renderings. You should see only a bright splotch of (direct)
sunlight for -ab 0, and increasing luminances for the areas receiving
reflected light with higher -ab bounces. Try it!

Also make sure to measure illuminance slighty OVER the plane - if you
are INSIDE geometry we all do not know what you will get for illuminance...

CU Lars.