RGB based smoke lighting

[ben_hamburg]

Hey guys,

I?m not sure I completely get how to use the RGB channel of the fire/smoke Sims.

At first I was thinking the RGB channel was kind of useless, since I could always change the color of the smoke in the render options by using "constant color" or a gradient.
But that wouldn?t work for different smoke sources in one emitter, since then all sources would have the same color/gradient.

Here is qhat I?m thinking right now:

1. I can tick "RGB" in a phoenix source and change the color.
2. If I now choose RGB based for the smoke in the render options, it will render the smoke with that color.
3. If I use multiple sources in one sim, I can use different colors and the smoke will render with different colors for each source.

Correct so far? Or are there any other uses for the RGB channel/render option?

[Svetlin.Nikolov]

Hey,

Well, the RGB channel is not vital to each and every kind of fire/smoke sim - you would want to use it when you have different colors in the same container which you cannot get at render time by mapping. Otherwise there is no point in it taking up cache file space, even though we found a better compression for RGB sometime around 3.0. However it's very important for getting realistic rendering with explosions where you often need to have different materials mix - soil, dust, smoke from burning materials, steam.

So, one use of the RGB channels is to have several sources emit in different colors and then the advection will mix these colors.

Additionally, you could map the RGB color for the surface of the emitter, which will produce different colors from the same source.

Hope this helps, cheers

[ben_hamburg]

Yeah, thanks, just making sure I got it right. Phoenix is so much fun, I?m so glad I have my short movie now to use it a lot more than usual...