I’ve searched the forum before and I have enabled env fog and inserted a vray env fog node with some success.
However I still cant find any proper descriptions how to get env shadows like god rays or underwater effects.
Also I would like to define a sphere like radius for fog so I can have objects coming out of it.
Are there any tuts or threads on here that I missed? I just cant figure out howto set up the other fogs for lights etc.
any help would be great!
crz
No one?`
I’ve been searching too but so far come up empty handed, if anyone has some links or tips on FOG it would be a big help..
This really needs to be in the (online) documentation!
There was a volume shader post somewhere in the forum. It explains V-Ray ENV FOG shader which looks stunning when you use an IES light and have objects to cast shadow.. If I have time I will post a tutorial video.
u mean something like this
Yes! I’m esp interested in the caustics/godray effect.
I’ve managed to make a primitve that has primary visability and cast shadows off and connect it to the Vray Env Fog via the relationship editing using a set.
I don’t get godray lights/shadows and I cant assign a procedural texture to the density as shown here
i think i could make some sample scenes when i get home from this fog examples 
stay tuned
p.s. just let me know what sample would u like me to make 1st, Example 5: Volumetric caustics?
hey bazuka, that would be amazing!
I hope this is not too much work, but these are the 3 main topics/scenes I’d be interested in.
1. (Spot-)Light a sphere or box as gizmo with god rays/shadow fog
if possible the differences between scatter, light and env fog.
2. Caustics for underwater scene
3. More than 1 Different Fogs in a scene.
i.e. One env fog in a box and then a sphere gizmo with an ambient light simulating a streetlamp. I’m pretty sure this is relationship editor stuff and binding a light fog to a light (which i have no clue how?!?)
Here is something for start (not 100% identical but close enough)
caustics_subdivs.zip (8.41 KB)
Hey Bazuka, thanks alot for the scenefile.
Looks pretty nice and simple in your rendering. I’ve been busy on an other project so this is kind of on hold but I opened it up and tried to find out what you did that was different to how ive been trying to achieve this up untill now. I thought you might have a noise or some kind of scatter texture from the look of it.
I will have to investigate further 
thanks man!
cant wait for 2) and 3)
nice u found it useful, am also a bit busy, but i hope ill make the scenes for a weekend ;), noise is not a texture thats the photon limit (30 photons)
cheers
2. Caustics for underwater scene
this one is simple all u need is a caustic seq map, for the video i did i used this nice app (Caustics Generator - Seamless water texture rendering)
and all u need to do is connect the map to light color
3rd sample im not sure i understand what u want, could u paste me the link of a image…
Have to try this when I’m back at work. No Vray on the weekend here
The third thing I was interested in was being able to create more than one effect at the same time in one render.
This is probably a bad example picture but here you can see it seems like 2 effects going on.
There is a simple env fog going on. Slightly fading away in the Background.
In the foreground all the street lights have a glow rather than a fog.
Instead of rendering out a MatID for the lamps and doing it in Nuke, I would like to know if its possible to set up a scene with different gizmos.
So from how I imagine it there would be a big Sphere encompassing the scene linked to the Env fog and a second fog set up to a group of Sphere gizmos placed around the lights.
Normally I would agree to do this with one fog but if you dont want a dense main fog and stronger glow around lights It would be great to control them seperately.
I think this is possible in max with the post glow and light fog?
This would also bring me to a 4) scenario … How can I link a fog to just one spotlight?
well if u take a look the pic ull notice that fog is all over the place/street, and the thing around the street lamp is an actually a glow + small amount of env. fog, but more glow than fog, i could make some similar scene and ull see
cheers
youre a champ!
looking forward to it
Thank you for this example, I too have been searching for the answer as to how to do this effect with Maya and VRay. I’m going to try it today. I was trying to make light rays come through a window into an interior scene. This should work for me, correct?
Bazuka, can you tell me how you set up this volume caustic scene? If I’m correct, you turned on caustics and put the VRayEnv fog into the environment shader slot? Is there anything attached to the spotlight?
Thank you.
Sam
Hi Sam,
setup is really simple as u can see there is only 1 light and thats it (i just added the vray light settings for photon control, but i think that u dont need it, try to turn it off)
everything else is going in render settings (caustic ON), and VRayEnv fog node…
