How to set up absorption color

[LudvikKoutny]

Hi,

I am having a hard time figuring out where do I set up absorption color for PhoenixFD sim grid. I need to get that tinted absorption effect where smoke reflects more of one color and absorbs more of the another, basically like this:

Thanks.

[georgi.zhekov]

Hello,

This is still in the "To Do" list I'm afraid.

[Guest]

You can achieve a similar effect with volumetric render settings by adjusting the smoke opacity and smoke color curves. Here's some quick test.

[LudvikKoutny]

You can achieve a similar effect with volumetric render settings by adjusting the smoke opacity and smoke color curves. Here's some quick test.

That is not what I am after. I need the volume color to respond to the light


Georgi Zhekov:
Thanks, hopefully it will be available soon. Right now, PhoenixFD volume material controls feel very simplistic and hardcoded, compared to a proper volume material such as VrayScatterVolume.

[georgi.zhekov]

Yes, there is quite a lot of space for improvement - we just need to get there

[Ivaylo Katev]

Use the smoke channel as blend mask for two colors, blue and orange, and put the output as smoke color The result will be different coloring for the dense smoke and the sparse smoke
Btw, just small physical clarification of the effect, sometimes understanding the nature of some effect can be helpfull. This is not difference in the absorbtion and reflection, it's actually smoke made of transparent particles.
The most volumetric shaders are using "dust" model , i.e. the smoke is made of small opaque colored particles. However all the materials become transparent at certain size, and if the particles are small enough (or the material is transparent even at macro scale), the smoke will look like this. In this model the peripherial color is NOT the opposite, its just white, but it looks blue because it's compared to orange (but nevertheless in this image it is really blue).

[Svetlin.Nikolov]

In summation, we have colored absorption in the TODO list and it won't be hard to implement, but it might slow the rendering down so we need to be careful when adding it. Hopefully we'll have this in the next few months.

Cheers!

[hammerbchen]

Hi,

While playing around with my new Nebula test, I realized you could get some "absorption" looking of the smoke by using "Based on Smoke" and adjust the color gradient you prefer.


Cheers,

Hammer