External 'God Rays'

[bubs]

I can manage to create nice 'god rays' on interior scenes, like this example I posted a while ago. http://www.indigorenderer.com/forum/dow ... &mode=view
But for the life of me I cannot get them to work on an external scene... can someone advise if these are possible, and if so a quick 'how to' would be greatly appreciated!

[thesquirell]

I managed to pull something out on my pic: http://www.indigorenderer.com/forum/dow ... &mode=view

It would help me a lot if you share your scene set-up. The basics are, there is a giant cube around the scene object, HG is almost white, a little bit of absorption, and some objects to block the light path.

[bubs]

Thanks thesquirell I'll give it a try... I was trying to redo this scene as 'out of the box' Indigo, at the minute the sunny haze in the centre of the image was added in photoshop

[Oscar J]

Gorgeous man, just gorgeous!

[thesquirell]

I love those birches!

Now, about the quick how to.
Put the cube around your scene objects so it covers all of your tree models. You don't need it infinitly wide and long. For the material for this cube, use Specular type, with these settings:
IOR=1, Cauchy B Coefficent=0;
Absorption Spectrum=RGB (241,241,241 (80 % Brightness in C4D)), Gain=80%, Gamma 1;
SSS=On, Scattering Spectrum= Uniform, Value 0.003
Phase Function= Henyey Greenstein, Value= 0.98, 0.98, 0.98, Gamma 2.2

This worked for my scene, but I am guessing, just as in every case with sss, and displacement, bumping, etc. it depends on your scene scale.

For getting these parameters right, I usually play with boxes and matches. Every model is replaced with thin, tall boxes, and the ground is just ground, without any texture. It speeds up the process, of getting them right, especialy when there is no light transmission on the leaves. Best of luck, and have a great time with awesome Indigo!

[bubs]

Put the cube around your scene objects so it covers all of your tree models. You don't need it infinitly wide and long. For the material for this cube, use Specular type, with these settings:
IOR=1, Cauchy B Coefficent=0;
Absorption Spectrum=RGB (241,241,241 (80 % Brightness in C4D)), Gain=80%, Gamma 1;
SSS=On, Scattering Spectrum= Uniform, Value 0.003
Phase Function= Henyey Greenstein, Value= 0.98, 0.98, 0.98, Gamma 2.2

Thanks for this. However, I am getting exactly the same results as every other method I've tried... a completely black render... not so much as a single pixel of light...

[thesquirell]

Usually that happens to me when I put my camera is in some sort of a medium, whose object's normals are pointing in the wrong direction. Did you try checking that up?

[bubs]

Usually that happens to me when I put my camera is in some sort of a medium, whose object's normals are pointing in the wrong direction. Did you try checking that up?

Yeah, was the first thing I checked. I am getting 'something' coming through when I change to Reinhard tonemapping tho... looks more like one of kklors crazy scenes at the minute tho!! (unfortunately not in a good way tho!!! )

[thesquirell]

Hahah, kklors is a great artist, I love his work, so it's a good thing, actually! Even in a bad way! Well...I used BiDirMLT render mode to get mine, with some standard camera ISO and EV adjustments. Try upping them alot, to see if they produce an image. If everything is as it should be, and your scene is complicated, it is just a clearing up/render process that is taking you from the pitch dark to the...some sort of an image. What kind of a host 3D app are you using? I am using C4D, but maybe there are some other members that could help you "from the inside". If you are using C4D too, you could send me .c4d file of your scene (promise not to steal anything) and maybe I can work something out for you.

[bubs]

Hahah, kklors is a great artist, I love his work, so it's a good thing, actually! Even in a bad way!

He blows my mind on a weekly basis!

What kind of a host 3D app are you using?

I'm SketchUp user (there's a clue in the forum post ) I'll try to have another play about soon, but way too busy at the moment! Thanks for your help tho!

The birches are from Xfrog by the way.

[Oscar J]

I love those birches!

How I misread this!

[bubs]

[thesquirell]

OMG, not again, I think I am starting to sound like a creep around here. First, I said something like "raped" in French, misspelling the word "voila" for "viola" (thanks CTZn for pointing that out), and now this... xD
Anyway, I am sorry I couldn't help you more with this, if you would like to, you can jump into the c4d very quickly and just import your scene there, and I could fix it for you. Since I am all out of ideas, there maybe something wrong with the exporters, but I never used SketchUp in my life, only Maya, 3Ds Max, and now C4D...
Let us know if you mange to find a solution.