It's definitely making more sense. However, the one thing that you still haven't clarified is what happens to base emission when you use emission scale?OnoSendai wrote:The emission scaling functionality now is basically a superset of the old efficacy scale functionality.Whaat wrote:Thanks a bunch! I guess the confusing part for me is that I still don't see anything about efficacy. Is emission scale the same as efficacy scale? What happened to power (watts) and overall luminous efficacy? (lm/W) These are familar terms to many users. All of my emitter presets were based on these values.OnoSendai wrote: EDIT: attached latest manual, which contains documentation for new shader language functions, and emission_scale.
How do I create a simple 100W incandescent bulb now?
The old way of setting the power drawn (Watts), and overall luminous efficacy (lm/W) was basically a convoluted way of specifying the luminous flux (lm) of the light, which is just the product of the power drawn, and the overall luminous efficacy.
With the new emission scale system, you can just set the luminous flux directly. In addition, you can also scale the emission of the light according to other measures, such as luminance, luminous intensity, and luminous emittance.
To create a 100 W incandescent bulb, using a figure of 13.8 lm/W from wikipedia ( http://en.wikipedia.org/wiki/Luminous_efficacy ), and 100 W, the luminous flux of the bulb is 100 W * 13.8 lm/W = 1380 lm.
For example, if I define base emission value to be RGB spectrum R=1000,G=1000,B=1000, that defines an emitter with spectral radiance in units of W m-3 sr-1. If I then set the emission scale for that material, does Indigo then normalize the RGB values and then set the luminous flux purely from the emission scale value, or do the two values (base emission and emission scale) work together some other way?
Also, what about blackbody spectra defined in base emission value? In the absence of the emission and emission scale parameters, does the spectral radiance value=1? How is the luminous flux calculated in this case?
What I am asking in a round about way is whether you can define a 100W incandescent emitter (say 2800K blackbody) WITHOUT using emission scale.
One last question that I don't think has been addressed: Can you use IES profiles with emitting materials? If so, how??