VrayEnviFog + GI + texture as source of light - quality - accuracy problem

V-Ray for Maya V-Ray for Maya :: Issues
1

Heya

I have a 8 bit image.
I have a fog covering the geometry with the image
I enable GI in order to render the light penetrating fog using IRR+LC as its a lot faster than raytracing.
I enable GI in envi fog settings and set it to 10 - no reason why 10 just test.
Now when I render that it renders very quick. But I cant change the size of samples or fog samples? Not sure. No matter what I change in GI settings I always get the same fog-light distribution. Big blurry dispersion of light.

How can I make it more accurate so it picks colors better off the geometry. I have lots of different colors and shapes coming from my texture and GI is blurring it all together and spitting off 3-4 variations of color rather than all.

Is there a way to increase sampling/quality of it?

I tried raytracing > light > no GI > samples in fog I had to hock up all the way to 2k and it still looks very bad…

I’m trying to create nice fog that does 2 things.
1 Create depth in scene and fade out objects - that can be done using blurry gi and so on.
2 Create glow from objects to nicely penetrate the fog - I would love to add some noise texture in density of fog but last time I tested it my renders went from 5 min to 1h+…

Thanks, bye.

2

Can you show a few images? I’m not sure I understand what your results look like.

Best regards,
Vlado

3

Hey Vlado

Right I tried to do test scene so I can send it up to you but I failed. It somehow did what I wanted but when I take it to larger scale for my project it dont work too well. I’ve attached few links below with the fog I’m trying to create.

specially this one

I really like how fog in this one just interact with light and so on. I know that when I use EnviFog with 3d texture in it it will render for ages. So my idea was to render it out to deep exr and then add depth to it in post/nuke with 2d/3d maps in 3d deep space. Not sure if it would work just a theory.

None the less I fail to create the light dispersion in fog for it. It always just end up being blurred with 500 pixel radius instead of 25 as I would want it… Not sure this one idea has been bugging me for a loong time. Will try to get you some real live scene that you can have a look at and see there is a way of improving it…

Thanks, bye.