[subspark]

Maxwell 1.7 has a fantastic new physical sky system. Unfortunately it is incomplete in its simulated accuracy. Is NL planning or currently working on Mie & Releigh scattering? And if so, will the feature be introduced in Maxwell Render 1.8?

Cheers,
Paul.

[KurtS]

I guess you mean Rayleigh-Mie?

[subspark]

Both are different and separate scattering properties actually.

The blue color of the sky is caused by the scattering of sunlight off the molecules of the atmosphere. This scattering is called Rayleigh scattering. It's more effective at short wavelengths (blue end of the visible spectrum). Light scattered down to the earth at a large angle with respect to the direction of the sun's light is predominantly in the blue end of the spectrum.

The scattering from molecules and very tiny particles (< 1 /10 wavelength) is predominantly Rayleigh scattering. For particle sizes larger than a wavelength, Mie scattering predominates. This scattering produces a pattern like an antenna lobe, with a sharper and more intense forward lobe for larger particles.

Mie scattering isn't strongly wavelength dependent and produces the almost white glare around the sun when a lot of particulate material is present in the air. It also gives us the the white light from mist and fog.

Theres actually a dramatic 'absence' of particles in the air of the polar regions where Mie scattering is not a present phenomenon. Very interesting!

I hope Mie and Releigh Scattering will be simulated in a future version of Maxwell and soon.

Cheers,
Paul.

[Thomas An.]

... but what is the reason exactly that the current system seems insufficient to you ? ... and ... how did you conclude that the current implementation does not supersede (or replace comparably) the Rayleigh-Mie methods ?

[subspark]

Basically all I am requesting for is distance fog. Thats as simple as I can put it for you. Maxwell doesn't perform this simulation just yet but it is something I'm sure most of you would wish for especially when making large outdoor areas.
Hope that explains it a bit better.

Cheers,
Paul.

[Thomas An.]

Basically all I am requesting for is distance fog.

gotchya ... yeah, fog is a reasonable expectation for the sky system.

[Hybaj]

The developer of Indigo has already done an atmospheric scattering implementation into his renderer but the rendering times are beyond anything really usefull. I suspect it would be the same for Maxwell since the technologies are very much the same.

to see what's going on look at this thread http://www.indigorenderer.com/joomla/fo ... php?t=4235

Actually if you really want to do the typical blueish foggish haze, then why not toss the z-depth information into aftereffects (or any kind of composition program that has 3d fog capabilities) and play with the 3d fog until it looks just ok. It requires a bit of color tweaking but I do this every time I need to have haze in my pic with good results

[-Adrian]

This reminds me of two old photos.



The sky was hardly visible, as the sun's brightness was spread over half of it. The camera saw more of the detail behind. Could be that kind of effect.

[subspark]

Thanks for the suggestion, Hybaj. Actually, I use AfterEffects every day in my visual effects studio. This is an approach I have taken for the meantime.

Nice images, Adrian! Did you take those?

Cheers,
Paul.

[-Adrian]

My father made them, with an "analog" camera. I had them in an album and quickly scanned them.