Fog

[Cruz]

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

[Cruz]

No one?`

[blackbox]

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..

[Cruz]

This really needs to be in the (online) documentation!

[Metzger]

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.

[bazuka]

u mean something like this

http://www.vimeo.com/20211627

[Cruz]

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
http://www.spot3d.com/vray/help/150S...ronmentfog.htm

[bazuka]

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?

[Cruz]

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?!?)

[bazuka]

Here is something for start (not 100% identical but close enough)

[Cruz]

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)

[bazuka]

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

[bazuka]

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 (http://www.dualheights.se/caustics/)

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...

[Cruz]

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?

[bazuka]

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